By Steven Goddard,
The headline reads “NASA Satellites Detect Unexpected Ice Loss in East Antarctica”
ScienceDaily (Nov. 26, 2009) — Using gravity measurement data from the NASA/German Aerospace Center’s Gravity Recovery and Climate Experiment (GRACE) mission, a team of scientists from the University of Texas at Austin has found that the East Antarctic ice sheet-home to about 90 percent of Earth’s solid fresh water and previously considered stable-may have begun to lose ice.
Better move to higher ground! NASA also reported :
In 2007, NASA generated this map (below) of Antarctica showing just how hot it is getting down there in the land of Penguins.
Now I am really worried! But wait……. There are a few minor problems.
Assume for a minute that we accept the GRACE numbers. The first problem is Antarctica contains a lot of ice : 30 × 10^6 km³. At 100 km³ per year, it will take 300,000 years to melt.
The next problem is with the NASA temperature map. From the NASA article “The scientists estimate the level of uncertainty in the measurements is between 2-3 degrees Celsius.” They are claiming precision of better than 0.05°C, with an error more than an order of magnitude larger than their 25 year trend. The error bar is large enough that the same data could just as easily indicate rapid cooling and blue colors. That will get you an F in any high school science class.
And that is exactly what happened. The hot red map above was preceded by a cold blue map which showed Antarctica getting cooler. What motivation could NASA have had to change colors without mathematical justification?
NASA justified their heating up Antarctica with this comment :
This image was first published on April 27, 2006, and it was based on data from 1981-2004. A more recent version was published on November 21, 2007. The new version extended the data range through 2007, and was based on a revised analysis that included better inter-calibration among all the satellite records that are part of the time series.
As I have already pointed out, this is absurd. Their error bar is so large that they could have painted the map any color they wanted. Apparently someone at NASA wanted red.
But why are we looking at temperature trends anyway? The real issue is absolute temperatures. Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing. How can you melt ice at those temperatures?
http://en.wikipedia.org/wiki/File:Antarctic_surface_temperature.png
I overlaid the Antarctica summer temperature map on the GRACE “melt” map, below. As you can see, GRACE is showing ice loss in places that stay incredibly cold, all year round.
The problem with GRACE is that it measures gravity, not ice. Changes in gravity can be due to a lot of different things beneath the surface of the ice. Antarctica has active magma chambers. Plate tectonics and isostasy also cause gravity changes.
We should be clever enough not to be blinded by technology. The claims that ice is melting in East Antarctica don’t have a lot of justification.
This study rubs me the wrong way.
“How can you melt ice at those temperatures?”
With a volcano… or a blow torch!
As usual, they are lying through their teeth.
I wish these nut jobs would put half this much time, money, and effort into at least trying to do something worth while……………
“”“Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002” “”
and frankly no one has noticed.
I guess the moral is, don’t go to sleep on the beach……
You don’t have to melt ice to reduce its quantity. Ice will sublime directly into water vapor when it’s cold enough, the winds are strong enough, and the effect lasts long enough.
A cold dry wind will sublimate the ice away, given enough time.
Perhaps wind has an effect on the Antarctic ice as it seems to have an effect on the Arctic, to a degree.
OK I’ll stop the sarcasm.
This is really starting to piss me off, why don’t NASA do their own job, as space association, and let NOAA fudge the data themselves, kapeesh?
Actually, in too many high school science classes erroneous assumptions will get you an A. That’s part of the reason why part of the public swallows these mangled half-truth stories.
NASA lies.
It’s a good thing they weren’t under oath to present “the truth, the whole truth, and nothing but the truth.”
Leaving out that tiny little fact that with 30 million km³ it will take 300,000 years for it all to melt serves to create a feeling that there’s a need for panic, a rush to fix an imaginary problem. In other words, a lie.
300,000 years. Hmmm … I wonder how many ice ages our descendants will face during that time.
Oh, how silly of me. We’ve already been told how we’ll be extinct by 2050, that the planet will become like Venus. Right.
Perhaps the high priests of climate “science” need to change the animal whose entrails they’ve been examining.
Does anyone monitor volcanic activity below the sea-ice? The British Antarctic Survey have sometimes quoted seismic activity which could possibly explain detachment of floating sea-ice from the land born ice. Is it unreasonable to suggest that sub-sea eruptions could thin the underside of the ice shelf? The air above could remain below minus 10ºC all year but the ice become thinner.
“They are claiming precision of better than 0.05°C, with an error more than an order of magnitude larger than their 25 year trend. The error bar is large enough that the same data could just as easily indicate rapid cooling and blue colors. ”
It is simply astonishing that this kind of CRAP is being published. We are in more trouble than I even thought (and I’m REALLY pessimistic).
Am I maths deficient or are they claiming to be able to make a reliable measurements to six decimal places?
Can we get some anti-alarmist legislation making it a civil offense to overstate official scientific reports based on some easily defined circumstances, such as this one. We already consider this academic dishonesty. Why not apply it to government. It would make the most interesting congressional debate.
Gosh. Not only is the BP spill insignificant compared to the volume of water in the gulf of mexico, it is insignificant compared to the volume of antarctic ice that somehow figures out a way to melt at << -20 deg-C !
I wonder if GRACE looks at any landmasses that have no ice and finds them melting at comparable rates?
The accelerating land ice melt scenario poses a problem for sea level rise because if too much is attributed to melting land ice then the steric component due to increasing sea temps must be reduced. The only solution is to exagerate the rise to 3 cm/ year to accomodate both scary scenarios.
http://www.argo.ucsd.edu/global_change_analysis.html#temp
Looking at the mass component of sea level rise from 2004 to 2008 as determined from Grace it appears that it reaches its largest amount in the fall when the Antarctic land and sea ice should be at its highest. Does this make sense?
When the time comes to cut American government spending, and that time is coming, I know a bureau and a university which are deserving candidates for cuts.
In this article from the Mail & Guardian, in which the study’s author, Jianli Chen, of the University of Texas at Austin was interviewed;
http://www.mg.co.za/article/2009-11-23-worlds-largest-ice-sheet-melting-faster-than-expected
this statement jumped out at me;
“The scientists used a computer model to take account of ongoing movements in the Earth’s surface caused by the retreat of glaciers at the end of the last ice age. Uncertainties in the model gave the scientists only a broad estimate of ice loss in the East Antarctic ice sheet of between five-billion and 109-billion tonnes a year.”
It is then used to justify the claim that:
“The East Antarctic ice sheet, which makes up three-quarters of the continent’s 14 00 square kilometres, is losing about 57-billion tonnes of ice a year into surrounding waters, according to a satellite survey of the region”
Nice to be accurate within an order of magnitude or so… Seems like another garbage model to me.
Also interesting is that Jianli Chen also turns up in this 2006 Washington Post article touting his model showing a rapidly melting Greenland ice sheet:
http://www.washingtonpost.com/wp-dyn/content/article/2006/08/10/AR2006081001557.html
Between Jianli Chen and Jinlun Zhang we seem to identified the primary sources of most Earth’s supposed ice losses…
Mike G , great question. Also, antarctica is basically an archipelago, and as tides move in an 18 year cycle this to could affect the very percise numbers claimed; as well as magma movemments within the mantel.
Johannes Rexx says: “You don’t have to melt ice to reduce its quantity. Ice will sublime directly into water vapor when it’s cold enough, the winds are strong enough, and the effect lasts long enough.”
Wrong. Cold ice temperatures reduce sublimation.
I wonder as to the likelihood that the melting of five or ten percent of the Eastern might lower the temperature of the oceans sufficiently to bring about a glacial period.
Johannes Rex,
From Sci-tech Encyclopedia
As Chis B hinted ,more like wind ablation than sublimation.
I know NASA is an arm of the government and the government (at present, but that’s changing) uses global warming to pass laws and regulations it wants. But where is the NASA that made the earth stand still to see a man take a step onto the moon?!
All together now:
M-I-C
K-E-Y
M-O-U-S-E
Mickey mouse study from a mickey mouse organisation trying oh-so-desperately hard to retain some relevance and funding.
This is just so unscientific.
Are you kidding me? This analysis is completely and utterly without scientific merit. I’m usually relatively interested in Goddard’s work but this is without a doubt a time when I can’t agree in the slightest. Antarctica (like most anyone knows) does not lose the majority of its ice through melting but rather through marine terminating glaciers having their ice go over the grounding lines. Antarctica does not even allow for significant melting due to temperatures being too cold. When you see accelerated mass losses like in Antarctica, it is due to increases in glacier velocity without subsequent increases in input ice. Thus more ice leaves then is replaced by meteorological conditions. The acceleration of glaciers in Antarctica is due to many reasons. In some regions it is due to the removal of buttressing ice shelves, in others it is due to grounding line retreats associated with increased subsurface ice melt by warming waters. There are also instances in the antarctic peninsula where there is melting occurring but because of its low resolution, grace does not see the mass loss as significantly as it has been.
Overall, to approach this topic in the manner that Goddard has is simplistic and shows that he did not read into the core literature which suggests why West Antarctic in particular is losing ice. As an individual who studies glaciology and has done so in Antarctica, I find it very important for individuals to become informed on the issues there, therefore I ask that this post be revised so as to not misrepresent what scientists are saying about what causes mass changes in the region.
How do you melt ice when it is below freezing?
By the magic that is AGW, and its satanic gas CO2.
With CO2, you do not need temps to be above freezing for ice to melt.
With AGW any new information, whether warm or cold, above or below freezing, wet or dry, is always proof that the world is facing a climate catastrophe.
To clarify that is warming ocean waters which has been remarked in numerous studies off the coast of the WAIS (see rignot et al. 2008a or b, Allison et al. 2009 and so on…)
There is an anomaly for the geoid given by GRACE:
http://earthobservatory.nasa.gov/Features/GRACE/page3.php
It is the difference for the month of August of 2002 from the average of the year for 2001 for the whole globe.
So on a scale of tens of meters, (as the GOCE plot of two months shows in the other thread,) anomalies are of the order of mms all over the globe. Models are fitted on these anomalies and give the estimates shown. These are gravity anomalies. The ones around Antarctica are used by this team to sell AGW. We are not shown the fits for other parts of the globe, which also must be changing according to the GRACE geoid. Maybe North America will be accumulating ice since there are positive anomalies there?
It seems very risky to me to assign these anomalies to ice melts, when the underlying continental shelfs may be redistributing on these scales. I know that Africa approaches Europe something like 2cms a year. From wikipedia plate tectonics:
The lateral relative movement of the plates varies, though it is typically 0–100 mm annually.[1]
Tectonic plates are able to move because the Earth’s lithosphere has a higher strength and lower density than the underlying asthenosphere. Their movement is thought to be driven by the motion of hot material in the mantle. Lateral density variations in the mantle result in convection, which is transferred into tectonic plate motion through some combination of drag, downward suction at the subduction zones, and variations in topography and density of the crust that result in differences in gravitational forces. The relative importance of each of these factors is unclear. Bold mine.
The research is interesting, the interpretation smells.
Seems to me there must be a policy decision to push the AGW panic button on all fronts.
SG asked: “The real issue is absolute temperatures. Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing. How can you melt ice at those temperatures?”
Keith Minto above pointed out that ice can be lost through sublimation. But also the ice sheets flow. They do not sit still. Ice from the interior flows toward to coasts. Warming along the coasts can affect the flow rate of ice from the interior.
My statements regarding mass losses being due to glacier accelerations have been proven without a doubt by Rignot et al. 2008a and b in which differential interferometric synthetic aperture radar is used to tangibly SHOW the increases in velocity measured using Radarsat, ERS 1 and 2, and Alos Pulsar. Finally, if this mass trend is incorrect as Goddard indicates, then why would the flux-gate method, the gravimetry method, and altimetry methods all have results which are extremely similar? Allison et al. 2009 summarizes all the studies which have been done on the mass balance of antarctica and only one method even suggests any gain and that study terminated in 2003 and was using low resolution radar altimetry instead of laser altimetry meaning basin level changes (such as on Pine Island Glacier, Thwaites Glacier and Smyth Glacier) could not be effectively seen or calculated.
Grace finds amazing scapegoat indeed. But it’s a lie. Look at the present temperature anomalies down there, exactly where the big melting is supposed to take place.
It looks like the cold spot is exactly where the big melt is supposed to take place. Whom are they kidding!?
To every complex problem, there’s a solution that’s simple, neat and wrong..
How can you have an error factor higher than the claimed change? This is preposterous. And the hot zones all appear to be shelf ice. Yawn. How about some measure of continental ice? And is the Eastern sea temps really above normal? This is a desolate area, with few measuring devices. The sats indicate the sea temps are falling. So why do they appear to be rising here?
Steve, where do you find that the temperature uncertainty in the satellite-derived temperatures are 2-3oC? You don’t see that in the links you provided. Where did those numbers come from?
-may have begun to lose ice.
Funny how a maybe is taken as a reason to declare catastrophic melting in subzero temps.
197 feet sea-level rise will happen in a blink of an eye, because fossil fuel C02 is a time-warp gas left here by visiting aliens bent on giving man something to destroy the planet with.
Great sci-fi stuff there.
“if all of this ice melted, it would raise global sea level by about 60 meter (197 feet).“
By now, I’d put more stock in Rain Dances.
Keith Minto says:
June 29, 2010 at 8:13 pm
“As Chis B hinted ,more like wind ablation than sublimation.”
Either way, that ain’t melt. Which, I believe, was Mr. Goddard’s point. Which in itself is funny, in a sad, pathetic way.
People actually earn a living, with our tax dollars, in an institution that is supposedly our best and brightest, and they apparently don’t understand that ice loss doesn’t equal to ice melt. They’re so wrapped up in “temp anomalies” that they can’t check an actual thermometer? It’s probably just as well. If they did look at the thermometer, we’d probably have to pay for a study that states CO2 has changed the properties of H2O to where it melts at much cooler temps now or some other such nonsense.
Funny my comments are still awaiting moderation despite an individual who commented after me having theirs accepted. Yet my comments have a substantial scientific basis and show actual flaws in the analysis compared to the other individual’s being a rant about AGW proponents. Not being accusational but I did try to put a lot of time and energy into the post for it to not appear…
ryanm…ur wish is my command…
The ice in Antarctica moves. At the South Pole it moves nearly 10 meters a year. Every year on New Years day they move the location of the pole as can be seen in the picture here:
http://www.trekearth.com/gallery/photo284509.htm
You don’t need either sublimation or melt to lose ice mass, and in this case the mass loss is not a result of either, but rather a result of ice thinning at outlet glaciers. This was initially detected by radar altimetry and later confirmed by satellite laser altimetry.
See this Nature paper: http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature08471.html
I have a question for those in a position to determine the answers.
If you spread 100 cubic kilometers of ice across the entire surface of the east Antarctic ice sheet, how thick would it be? And just for giggles, given the conditions in Antarctica, would that much sublimation on an anual basis be a realistic possibility?
richcar 1225 says:
June 29, 2010 at 7:50 pm
The accelerating land ice melt scenario poses a problem for sea level rise because if too much is attributed to melting land ice then the steric component due to increasing sea temps must be reduced. The only solution is to exagerate the rise to 3 cm/ year to accomodate both scary scenarios.
http://www.argo.ucsd.edu/global_change_analysis.html#temp
Looking at the mass component of sea level rise from 2004 to 2008 as determined from Grace it appears that it reaches its largest amount in the fall when the Antarctic land and sea ice should be at its highest. Does this make sense?
Interesting to see at your link that the steric component is now estimated to be 1/3 of sea level rise. IPCC AR4 had it at just under 1/2. I did some calcs on this and found the rise in sea level due to thermal expansion (steric component) would require much more excess energy than co2 could account for, event at IPCC inflated sensitivity values. It must have come from increased insolation, i.e. less tropical cloud cover.
But the new value gives more to melting, even though there is the dropping off of temperature and levelling out of ocean heat content globally since 2003. If they are right, it does mean significantly higher arctic temperatures, yet ice there increased in 2008 and 2009. I note the graph at your link only runs to 2008…
Perhaps they just keep fiddling with the proportions of the attributions so they can quote whichever study is convenient for the scare du jour.
I agree with JDN – we need to start looking at alarmist statements legally.
Alarmist statements have a real impact on society and individuals just as false representation does in commerse – in fact worse, because we can’t choose to not purchase the product – it is foistered on us with authority.
If NASA carries on business in any way, then their statements might fall under the US equivalent of the Australia Trade Practices Act. As many people invest based on these statements, maybe they could be construes to fall under corporations laws of financial institutions laws.
Were NASA’s statement touting an investment prospectus or a product, omiting the fact that Antartica would take 300,000 years to melt would be an omission of a material fact . If this was a prospectus, in Australia this would be a criminal offennce.
Are there any US lawyers who can comment on any prospect of forcing truth using existing laws?
Now isn’t that interesting !,worth an investigation by itself, 10 metres eh , bet it is moving north.
jeff brown
The quote is in the linked NASA article.
I get it now. Antarctica isn’t warming, melting and raising sea level. It is actually cooling, sublimating and not raising sea level.
And ice 1000km inland is rapidly finding it’s way to the sea at outlet glaciers with temperatures averaging -50C during the year.
And NASA has done everything they could to make sure that people understand that this has nothing to do with CO2 or global warming.
LMAO
I have a different problem with this study. I don’t find that it makes sense that the gains and losses would be where they are claimed to be:
1. Why is there a gain of 2 mm of thickness just inland of the place where there is a loss of 2 mm of thickness?
2. Why is there a gain of about a mm of thickness out in the ocean at the top of the image?
3. Why is there a “nimbus” of light blue (ice loss) on both sides of the West Australia Peninsula. The eastern side generally has lots of ice, while the western side usually has none … how can they possibly be losing ice at the same rate?
4. How can the ice loss at sea be the same as the ice loss on land? Why is there no change in loss at the point where the ice leaves the land and starts floating in the ocean?
5. The general trend over the period of the study was an increase in Antarctic sea ice area … why does this not show up in the GRACE graphic? Surely if it can tell us the difference of 1 mm in sea ice thickness, we should be able to the increase in sea ice.
For me, it doesn’t fly. I’d have to see a lot more data before I’d believe that this GRACE data is ready for prime time.
Finally, they have chosen a color scheme that paints everything within about ± 1 mm from zero the same color green … if (as they claim) a 1 mm loss is the size of the signal they are discussing, that’s enough less than helpful as to suggest deliberate action.
“The ice in Antarctica moves. At the South Pole it moves nearly 10 meters a year. Every year on New Years day they move the location of the pole…”
Isn’t this because of the wobble in the earth’s axis? Also, just an observation from a research trip in the austral summer of 1977-78. When I was working in the Dry Valleys on the coast of Antarctica the sun’s radiation was so intense during the peak of summer that the glaciers would send a stream of melt water down the valley and the noise of rushing water could be heard for miles. As the sun sunk lower on the horizon as summer came to an end, the mountains would cast a shadow on the glacier’s tongue and the sound of rushing water would cease abruptly. This sudden cessation of noise was surprising, almost as if a switch was turned off. It was fascinating to me how the sun’s energy and the glacial ice/water was in such a delicate balance. The cause and effect seemed obvious at the time; never occurred to me that CO2 was involved.
Brian Angliss
The GRACE map shows thinning nearly a thousand kilometers from the coast. That has nothing to do with outlet glaciers.
GISS does not show any significant warming in the waters around Antarctica.
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=5&sat=-1&sst=3&type=trends&mean_gen=05&year1=1960&year2=2010&base1=1951&base2=1980&radius=1200&pol=reg
RSS shows cooling around WAIS
http://climateinsiders.files.wordpress.com/2010/06/msu_amsu_channel_tlt_trend_map_v03_2.png
The poles are great places to lie about because relatively few people ever see them, let alone notice some kind of amorphous change over the decades. It’s bad enough when the AGW crowd talk about changes that are(n’t) happening in our neighborhoods but when it comes the the hidden corners of the globe – The poles, at depth, high desert – virtually all first hand knowledge to counter their statements is in very short supply.
Robert:
And how do you account for the uncertainty in the isostatic adjustments? It is the 900 pound gorilla that affects all of those unanimous studies you are quoting. In West Antarctica we have some idea about it, based on GPS measurements on exposed nunataks, but in most of East Antarctica there is no exposed bedrock, so it’s really just guesswork.
A couple of months ago a similar complaint was lodged here, to which one of the moderators replied that WordPress presented the comments to them in LIFO sequence, so that if the moderator took a break for an hour or two, comments could get considerably out of sequence. (Not that that’s necessarily what happened in your case.)
If glaciers are out-flowing faster because edge-ice has melted because of warming seas, shouldn’t there be a lot more icebergs among the sea ice? Is anyone tracking what the percentage or amount of bergs is? If not, why not?
Roger Knights
If there were a recent change in the rate of glacial movement near the coast, it would take tens or hundreds of years for the effect to propagate 1000km inland.
Ice is extremely viscous at -50C.
From Wikipedia
The Antarctic Plate is a tectonic plate covering the continent of Antarctica and extending outward under the surrounding oceans. The Antarctic Plate has a boundary with the Nazca Plate, the South American Plate, the African Plate, the Indo-Australian Plate, the Scotia Plate and a divergent boundary with the Pacific Plate forming the Pacific-Antarctic Ridge.
The Antarctic plate is roughly 60,900,000 square kilometers[1]. It is the fifth biggest plate in the world.
The Antarctic plate movement is estimated at least 1 centimeter/per year towards the Atlantic Ocean
1cm per year laterally measured, but this means there is motion and redistribution below of the masses that compose the plate, and it is logical to believe they are of the same order of magnitude. This is different from the isostatic corrections taken because of the ice volume. The ground moves and changes densities.
It is not possible to solve an equation with more unknowns than data inputs, which is what they are doing. They are ignoring changes in gravitational pulls due to tectonic motions which are of the same order of magnitude as the gravitational changes they measure.
I worked at Vanda Station in the Dry Valleys of Antarctica for 4 months.
The station is on the edge of Lake Vanda – a 5×1 km lake that is some 270 m deep. It is an inland lake that is fed by melt water from a coastal glacier and is about 15 km east of the divide of the transantarctic mountain range. It is very sensitive to climate change and during the eighties and early nineties it was rising by 600mm during the summer and losing 300mm from sublimation causing a net rise of 300mm per year. this rise has now ceased. The highest level the lake reached was 46 m above the 1985 level and that was 5000 year ago. It has also dropped to only 70m depth during some ice ages.
The point for this discussi0n is that in Antarctica there is negligible melt, sublimation is the main form of ice loss from the surface. This lake gives some indication of the rate of sublimation from the surface of antarctic ice (the rate would may be slower on the plateau as it is colder, but the air is also dryer which would increase sublimation).
On the other side there is accretion of ice from the atmosphere plus a miniscule amount of fallen snow (5mm / year near the divide at the head of the )Wright Valley.
However it is difficult to determine how much snow falls. Many people fail to understand that blizzards are blown surface snow – not falling snow. As these blizzards can have the air to 1000 ft full of snow it is impossible to detemine how much snow falls relative to what is just being blown around.
In December January when the sea ice on the Ross Sea has broken out then any cloud moving inland across the continent will leave snow where ever the cloud is in contact with the land – but it rarely falls as snow.
There is some 20 years of data on the rate of ablation of glaciers on the edge of the plateau and on various lakes in the dry Valleys but when NZ government formed NIWA (National Institute of Water and Atmosphere) they told the hydrologist in charge of this project to drop his data in a rubbish bin – which he did and then put it in his car. Hopefully it will emerge some day.
This was pretty criminal as his data on the glaciers would be very useful today to look at what is actually happening in Antarctica from 1974 to 1992.
Hope that provides some useful information for those not familliar with Antarctic ice.
The next problem is with the NASA temperature map. From the NASA article “The scientists estimate the level of uncertainty in the measurements is between 2-3 degrees Celsius.” They are claiming precision of better than 0.05°C, with an error more than an order of magnitude larger than their 25 year trend. The error bar is large enough that the same data could just as easily indicate rapid cooling and blue colors.
I’m not sure this is quite what they mean. Individual single measurements may have an uncertainty of 2-3 deg but that’s not the same as the uncertainty in the trend. If the uncertainty is due to a lack of precision then with a large enough sample the errors should pretty much cancel themselves out. Consider this analogy:
Say I want to measure the average height of an adult male in the UK but can only measure to the nearest foot. This basically means that anyone below 5ft 6in is recorded as 5 ft and anyone above 5ft 6in is recorded as 6ft (ignore those below 4ft 6in and above 6ft 6in for this purpose). The uncertainty in the individual measurements is clearly quite larege. However, providing I take a large enough sample – and one which is representative of the population as a whole I should still get a mean value which is not too far wrong. From a sample of 1000 I should get ~160 (16%) who are recorded as being 5ft tall and ~840 (84%) as being 6 ft tall. The mean of the sample would therefore be 0.16*5 + 0.84*6 = 5.84 (i.e. ~5ft 10in).
This is actually not a particularly good example because the uncertainty is not evenly distributed around the mean of the population. For example if the true mean height were 5ft 6in then we’d get around half measuring 5ft and half measuring 6ft (mean = 5ft 6in). The point being that if the uncertainty/errors are understood then they can be managed and – even if there is a bias – it won’t necessarily affect the trend.
It seems to me that the temperature of the oceans around Antartica is irrelevant. They are, and have been, above freezing for a very long time. Similarly the inland ice in antartica is at an average temperature which is below freezing. It seems to me that you will only get appreciable loss of ice when the inland ice moves towards the sea where it melts in the warmer waters. It is not at all clear to me what that mechanism might tell us about AGW. Any connection it might have to AGW is extremely obscure.
Of course, what we are really interested in here is not melting ice, or even rising sea levels. What we are really interested in is average loss of land area due to (possibly) rising sea levels. We don’t need any clever technology to check for average loss of land area. We need a good map from a hundred years back and a good map from today – and someone with time on their hands to compare the two.
Seems a lot of this “science” is about spending as much money as possible, rather than being as effective as possible.
Lets say that the active magma under the place is melting the lower regions of ice, for the sake of arguement. Cap and Trade isn’t going to do a thing about it.
0.1°C ±3°C
That’s the Antarctic situation cleared up then.
Steve Goddard,
It might be useful for you to respond in detail to Robert’s remarks which do not at all seem tangential to this discussion. Please?
Be careful. The entire atmosphere above you may come crashing down on you and crush you too.
Peter Foster says:
June 30, 2010 at 12:59 am
I worked at Vanda Station in the Dry Valleys of Antarctica for 4 months.
The station is on the edge of Lake Vanda – a 5×1 km lake that is some 270 m deep. It is an inland lake that is fed by melt water from a coastal glacier and is about 15 km east of the divide of the transantarctic mountain range. It is very sensitive to climate change and during the eighties and early nineties it was rising by 600mm during the summer and losing 300mm from sublimation causing a net rise of 300mm per year. this rise has now ceased. The highest level the lake reached was 46 m above the 1985 level and that was 5000 year ago. It has also dropped to only 70m depth during some ice ages.
???
This last sentence “It has also dropped to only 70m depth during some ice ages” implies that the melt stopped during the ice ages, right?.
You are saying that the observation that the rise has ceased points to the direction of cooling, no? Not enough summer melt?
Who was the hydrologist in charge?
anna v says:
June 30, 2010 at 12:37 am (Edit)
It is not possible to solve an equation with more unknowns than data inputs, which is what they are doing. They are ignoring changes in gravitational pulls due to tectonic motions which are of the same order of magnitude as the gravitational changes they measure.
Well said Anna. So in layman’s terms, it’s a load of old cobblers.
I’ve always wondered why NASA never went back to the moon, or managed to build new and approved space vessels.
Now I know. They ousted all the good engineers for climate extremists.
All that needs to be shown!
Construction Crane Buried in Ice Sheet
http://www.iceagenow.com/Construction_Crane_Buried_in_Ice.htm
Oh!,how silly of me, the DAGW is heating the steel thus the crane and towers are sinking
“Thinning reduces lateral traction and through grounding line retreat, basal traction…these events lead to accelerated ice flow and thinning directly upstream, which can then diffuse rapidly further inland [Joughin et al., 2003; Payne et al., submitted manuscript, 2004]…Ocean currents on average 0.5_C warmer than freezing appear to have precipitated a sizable drawdown ofice from the WAIS interior. Elsewhere, ice shelf erosion [Shepherd et al., 2003] and disintegration have preceded increased discharge from glaciers upstream [De Angelis and
Skvarca, 2003]. The consequences of a warming ocean on the grounded Antarctic ice mass needs more attention than it has received to date [Warwick et al., 1996].”
“Ocean temperature was estimated beneath each ice shelf from vertical profiles recorded at 22 stations (see Figure 1) occupied during a 1994 cruise around Pine Island Bay [Giulivi and Jacobs, 1997].”
Warm ocean is eroding West Antarctic Ice Sheet
Andrew Shepherd,1 Duncan Wingham,2 and Eric Rignot3
GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L23402, doi:10.1029/2004GL021106, 2004
Okay Goddard, your move. Prove its not warming there, and that glacier acceleration does not propogate inland. Due note, there is a plethora of evidence which shows that propogation occurs very quickly. I’ll look up the papers in a few minutes. Radar interferometry allows for direct measurements of glacier accelerations. It’s not guess work.
The whole truth!
VolcanoesThe South Pole
http://hotgates.stanford.edu:3455/SouthPole/554
“The profiles in Figure 8 show a particularly close correspondence between sudden, large-scale retreat and
sudden acceleration. In this case, a retreat of 1400 to 1600 m between 1998 and 2003 was associated with an acceleration of 40% for both glaciers.”
“The acceleration appears to be linked to frontal retreat and thinning. We suggest that thinning of the buoyant glacier termini under a prolonged negative mass
balance regime can explain both the acceleration and retreat
[after van der Veen, 1996; Vieli et al., 2001].”
Widespread acceleration of tidewater glaciers on the Antarctic
Peninsula
H. D. Pritchard1 and D. G. Vaughan1
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, F03S29, doi:10.1029/2006JF000597, 2007
“Between 1996 and 2007, Pine Island Glacier sped up 42% and ungrounded over most of its ice plain. Smith Glacier accelerated 83% and ungrounded as well.
Speed up propagates beyond the limit of the PALSAR data…
The inferred near balance of the 1970s suggests that the ocean changes responsible for that evolution originated for the most part around that time. This coincides with a period of increasingly more positive southern annular mode (SAM) [Marshall et al., 2004], which has increased westerly wind flow, leading to northward-drift of surface water and sea ice, and bringing warmer Antarctic circumpolar water (ACC) against the coastline.”
Changes in West Antarctic ice stream dynamics
observed with ALOS PALSAR data
Eric Rignot1,2
GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L12505, doi:10.1029/2008GL033365, 2008
Once again, the evidence supports my conclusion.
“Thomas et al. (2004b) showed that the ungrounding of the ice plain upstream of
the grounding line was the most significant control on glacier speed, and that the
corresponding perturbation in force balance could propagate far upstream
quickly.”
“One implication of these observations is that ice shelves do not need to
experience surface melting, rifting or collapse to cause significant glacier change.
A thinning ice shelf in front of a weakly grounded glacier may trigger a rapid
retreat with important consequences.”
“Jacobs et al. (1996) found that warm circumpolar deep water intrudes onto the
continental ice shelf in Pine Island Bay. Jacobs et al. (1992) subsequently showed
that the signature of ice shelf melting in the Amundsen Sea is observed in a
40-year time-series of oceanographic data collected in the Ross Sea. A warmer
ocean is the only plausible explanation for the simultaneous melting of all ice
shelves, the simultaneous glacier speed up from an entire region and the absence
of ice shelf thickening in response to faster flow (Shepherd et al. 2004; Payne et al.
2004).”
Changes in ice dynamics and mass balance of the Antarctic ice sheet
Eric Rignot
Phil Trans. R. Soc 2006, 264, 1637-1655
Thereby proving-
-Inland propagation occurs quickly
-melting on ice shelves is not required for the loss of mass
-important portions (pine island bay) of the WAIS are experiencing oceanic warming.
Lets see your evidence countering mine?
My take on this would be that the AGW crowd are putting their backs to the wall as they are surrounded by inconvenient facts. The window of opportunity for their fame and glory is rapidly diminishing. The American government is under pressure from up coming senate election, to do something about ” carbon ” or its all over red rover. Much money is at stake, not just in grants, but carbon trading per sec. Rabidness is getting louder, but less are listening.
As to the ice melting and or falling into the ocean, that makes the water cold, sucking heat out of the worlds climate. The southern hemisphere is having a touch of the unexpected colds at the moment. With some nasty looking cold fronts moving up from antarctic at this time it sure not getting warmer soon.
The alarmists are pointing at the melt of the arctic as proof of AGW,, this is also pumping heat out of the ocean. With both hemispheres pumping heat out of the ocean we can expect some nasty winters.
Warmer winters are a keystone of AGW how many cold ones will it take before they go ooh aah well umm er er maybe,,..
Robert
Suppose there had of been a recent increase in ice movement near the terminus of the glaciers. It would take hundreds of years for that to be expressed as changes in ice thickness 1000km away, as is claimed in the GRACE maps.
Ice at -30C is extremely high viscosity. If they dig a hole in the ground a mile away from your house, does it change the elevation of your house much?
http://www.nature.com/news/2005/050516/full/news050516-10.html
Willis,
the west side has more outlet glaciers than the east in this region (see Cook et al., 2005 )
Brian Angliss,
Leakage from outside the ice sheet occurs because the averaging function extends beyond
the boundaries of the ice sheet. To account for the omission of l = 1 we used degree-1 coefficients calculated from a combination of GRACE and ocean model output as described by Swenson et al. [2008].
Several studies pointed out already that the ice sheet losses were
accelerating, e.g., Interferometric Synthetic Aperture Radar (InSAR) surveys [Rignot and Kanagaratnam, 2006; Rignot et al., 2008a, 2008b], GRACE [Velicogna and Wahr, 2006b; Chen et al., 2006a, 2006b], and altimetry [Howat et al., 2008; Krabill et al., 2004]
Yet, results from the analysis of glacier motion and surface elevation changes suggest a continuous increase in
mass loss until 2006. This supports a quadratic trend for the GRACE mass observations, instead of a straight line.
Increasing rates of ice mass loss from the Greenland
and Antarctic ice sheets revealed by GRACE
I. Velicogna1,2
GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L19503, doi:10.1029/2009GL040222, 2009
TTY, see below:
Mass changes in three regions of Antarctica that display prominent geoid-height change are determined by adjusting predictions of glacier melting at the tip of the Antarctic Peninsula and in the Amundsen Sea Sector, and of the glacial-isostatic adjustment (GIA) over the Ronne Ice Shelf. We use the GFZ RL04, CNES RL01C, JPL RL04 and CSR RL04 potential-coefficient releases, and show that, although all data sets consistently reflect the prominent mass changes, differences in the mass-change estimates are considerably larger than the uncertainties estimated by the propagation of the GRACE errors. We then use the bootstrapping
method based on the four releases and six time intervals, each with 3.5 years of data, to quantify the variability of the mean masschange bestimates.
Regional ice-mass changes and glacial-isostatic adjustment in
Antarctica from GRACE
Ingo Sasgen a,⁎, Zdeněk Martinec a,b, Kevin Fleming a
Earth and Planetary Science Letters 264 (2007) 391–401
Once again, I am not trying to overflow people with literature. It is just I see that clearly individuals need to refresh their knowledge on antarctic glaciology prior to making posts they can not support with evidence…
http://www.wunderground.com/global/stations/89009.html
goddard says,
“Published online 19 May 2005 | Nature
East Antarctica puts on weight
Increased snowfall over a large area of Antarctica is thickening the ice sheet and slowing the rise in sea level caused by melting ice.
A satellite survey shows that between 1992 and 2003, the East Antarctic ice sheet gained about 45 billion tonnes of ice ”
Oh come on Goddard, that’s an old paper which uses an old method that has been shown to overestimate mass changes. Since that time there has been a plethora of studies which show clearly that Antarctica is losing ice. These studies include, Chen et al. 2006, Rignot et al. 2008a,b, Cazenave et al. 2009, Velicogna 2009, Chen et al. 2008, Allison et al. 2009, Pritchard et al. 2009, Gunter et al .2009… the list goes on. Do you know there hasn’t been a single study using laser altimetry, grace or radar interferometry that has put a positive mass balance on Antarctica. There’s a reason for that.
Your example is using radar altimetry which has a bias towards overestimation of ice gains in regions which are sloped or on smaller glaciers cause of its low resolution.
“Radar altimeter signals
penetrate the near-surface snow and ice layer, and the
results can be affected by the internal structure.
Satellite-borne radar altimeters have a relatively large
footprint (2–3 km), which can lead to a bias over
rough or sloping terrain, and challenge measurement
accuracy in narrower outlet glaciers.”
Allison et al. 2009
People always drag out that study and yet its so easy to refute because laser altimetry is MUCH MORE ACCURATE and show losses. Radar interferometry shows accelerations leading to more losses and GRACE shows a mass loss. Your point is moot and without scientific merit. The glaciological community does not even use old radar altimetry anymore because of these biases. We have been waiting for the new cryosat-2 to start gathering data because of its higher resolution radar altimeter.
Now please, don’t drag out that study anymore unless you have a means of defending the results. Notice the authors of that study have since been collaborators in my previously mentioned studies…
Last winter, temperature at the South Pole hit -106 degrees and the last time I looked, the average annual temperature in Antarctica was -58 degrees. That means in order to melt any ice, the temperature must rise 58 + 32 degrees = 90 degrees just to get to the melting point of ice. I don’t think the Antarctic ice sheet, which is well over 10,000′ thick, is going to melt at these temperatures.
West Antarctica is surrounded by ocean water, which has warmed during the 1977-1998 warm period, and has caused minor melting, but that’s a totally different story than the main continental ice sheet which lies well to the east and shows no signs of melting.
We know there is liquid water beneath the Antarctic ice: Lake Vostok for example. So, the whole premise of this post is wrong.
The very NASA article that “Steven Goddard” links to explains how ice can be lost without surface melting. The very question that so confuses him is answered already!
Secondly, uncertainty in absolute measurement isn’t the same as uncertainty in relative changes. This is a well-known situation in measuring temperature, where we can’t be sure of the exact temperature, but we can measure changes (or anomalies) with great precision.
Anthony Watts, this isn’t the first post by “Steven Goddard” displaying a woeful lack of regard for basic research or fact-checking. Continuing to post his “insights” will damage your credibility. Does this concern you?
“this is astonishing”, “this is incredible”, “it’s absolutely criminal”, “where do these people come from”, “lies, lies, lies”, “NASA’s a joke”, “this isn’t science”, “this is political, it’s NOT science”…….
Sure sounds like people are beginning to wake up. Wonder what’s going to happen when we realize the truth of what was going on while we were asleep in bed with visions of sugar plums dancing in our heads? The bigger government becomes, the harder it is to keep it in check. Eventually it reaches a critical mass and becomes a runaway, out of control, no stopping it, etc., etc., …. (the more we want, the more we’re going to pay –or– the less we watch, the more we’re going to lose –or– there is no autopilot for life, liberty, and the persuit of happiness).
To Robert & David,
It’s comfortable taking pot shots against Steve Goddard from the sidelines, isn’t it? So let’s see you both man up and write your own articles like Steve does. Show us how either of you withstand drive-by criticism.
Robert,
You used an interesting phrase in your last post – “is using radar altimetry which has a bias towards overestimation of ice gains in regions which are sloped”
You do understand the difference between “gaining” ice and losing ice?
Robert,
Again, you wrote “overestimate mass changes”
Overestimation is a completely different concept from having the wrong polarity.
Methinks you are being extremely intellectually dishonest.
Robert,
One more point re your dishonest posting.
This article is about East Antarctica, and you are referencing studies and data which include West Antarctica.
anna v,
Thanks (again) for your contribution and insight here. I’ve learned much truth/facts from you. Noticed you were missing for a period of time back a few months ago and were hoping you were okay, what with all the “problems” there in Greece.
Your observation – Seems to me there must be a policy decision to push the AGW panic button on all fronts. is spot on. The Obama administrations Department of Politics & Propaganda is burning the mid-night oil – (well, they have to do something with all that oil gushing up in the Gulf) and they are damn good at it. Unfortunately, it’s 1 of ONLY 2 things the administration is good at. The other is being TOTALLY inept at everything else – – well, there is 1 other thingthey’re great at, but let’s not get into personality disorders.
@ Robert “Lets see your evidence countering mine?”
I don’t see he has to provide any evidence countering yours – the “evidence” you provide is merely conjecture.
Firstly, if the ice is reaching the ocean faster, why would the absolute temperature make any real difference? The ocean is significantly warmer then the melting point of the ice and therefore ANY ice at ANY time reaching the ocean will be forced to melt – this is always going to be the case regardless of its absolute temperature. Secondly, even if the ice in glaciers close to the ocean were to melt entirely the ice further inland will not readily reach the sea since it is effectively locked to the terrain beneath it. Finally, if the ice on the glaciers has been flowing to the sea for some considerable time then you need to explain why the glaciers are still there at all given that actual precipitation is very low in Antartica (of course you don’t actually need precipitation for ice to form).
Realistically, how can there at once be glaciers in the Alps whilst simultaneously claiming that glaciers in Antartica are melting at a dramatic rate.
Robert,
you make some interesting technical points. However, I’ve always taken ice extents from cryosphere today, and they show a positive anomaly for the SH. Yet you seem to be claiming the opposite.
David
A claimed trend of 0.03-0.05C per year with an error of 0.12C per year is meaningless. Particularly when the same organisation was previously showing a trend of -0.1C per year in the same region.
In fact, it is complete nonsense.
David
Does it concern you that you are defending unsupportable positions?
Is the paper claiming accelerated melting? No, it’s claiming accelerated mass loss.
Ice loss in Antarctica is primarily due to calving at the terminus of the ice flows – on the order of 95%+ of all ice mass is lost by ice breaking off and forming icebergs. Very little of the annual ice loss in the Antarctic is due to melting, and this occurs in only a few locations.
Temperature does influence this process. Warmer water can undermine the integrity of the ice tongue, and cause accelerated calving. Warming temperatures in the accumulation zone of the glacier, as long as they are still below freezing, can increase the annual accumulation rate – which can go into accelerating the ice flow, or increasing the ice sheet thickness, or a bit of both. So temperature anomalies, depending upon location, can lead to increases or decreases in ice mass.
Please understand that glaciers and ice sheets lose mass in below freezing temperatures – tidewater glaciers like Columbia Glacier still lose ice in the winter, as do the Greenland and Antarctic ice sheets.
I would urge readers of this blog to pick up or rent a copy of The Physics of Glaciers if they are interested in an in-depth discussion of glacier processes. This video (http://courses.washington.edu/ess431/Pictures/VG83_main_stream_arrival_Mpeg4_u1.mov) of Variegated Glacier will give you an idea of how fast these rivers of ice can move. Granted, Variegated Glacier is a surge glacier, but ice moves on the order of kilometers per year in some flows on these ice sheets. Jakobshavn Isbræ comes to mind.
stevengoddard says:
June 30, 2010 at 6:58 am
Robert,
One more point re your dishonest posting.
This article is about East Antarctica, and you are referencing studies and data which include West Antarctica.
Perhaps the original poster should have confined his discussion to East Antarctica then?
Goddard,
i made a mistake in the way I wrote that statement. Radar altimetry has a bias towards more positive mass balance measurements is the correct way it should have been written. Once again, I refer you to Allison et al. 2009 for confirmation that it was just an error in sentence structure. Radar Altimetry does in fact have a bias towards more positive values because altimeter mode is downward facing which results in a lower resolution swath. Angled radar such as used in radar interferometry, counterintuitively has a much greater resolution all to do with the way the signal reaches the ground and so on.
The result is that radar altimetry overestimates positive mass changes on sloped regions such as the Antarctic Peninsula. And the other result is that radar altimetry’s low resolution (2-3 km) doesn’t identify individual basin level changes. For example a small glacier can lose much more ice than its surroundings but because of the low resolution data, the glacier losses are smoothed out. Once again, you can look this up yourself if you think i’m being “intellectually dishonest” but the truth of the matter is that you were nitpicking my own sentence errors because you could not refute the overwhelming science I presented.
Smokey says:
June 30, 2010 at 6:39 am
“To Robert & David,
It’s comfortable taking pot shots against Steve Goddard from the sidelines, isn’t it? So let’s see you both man up and write your own articles like Steve does. Show us how either of you withstand drive-by criticism.”
Look, I don’t step into the fray a whole lot here because there are some articles I really enjoy but it was clear from the outset of this article that Goddard did not adequately research the literature or understand how Antarctic mass changes are occurring and what are the primary drivers behind these changes. It is not hard to find the accurate information pertaining to the region but yet it is clear that he did not attempt to do so.
He essentially questions Grace mass anomalys based upon the idea that no melting is occurring but yet ignores that the overwhelming majority of ice changes in Antarctica are due to accelerations of glaciers and increased ice discharge. That doesn’t fly with. If you’re going to make a post, you have to take the time to research the subject.
David Smith says:
June 29, 2010 at 7:56 pm
When the time comes to cut American government spending, and that time is coming, I know a bureau and a university which are deserving candidates for cuts.
__________________________________________________________________
How about the WWF who recieves 20% of its funding from government
“World Wildlife Fund financial condition June 30 2001: Government Grants $24,589,994 “
I would like to see most government spending cut to the bone and most of the bureaucracy and pork cut. I would also like to sef lobbying and campaign contributions by activist groups, corporations or foreigners made illegal. I thought we were supposed to have a government by the people for the people not a government by the corporation for the corporation.
I would also like to see the “read the bill law” passed.
Goddard,
pertaining to your criticisms of those studies being on Antarctica as a whole, Rignot et al. 2008a calculated ice losses for both the EAIS and WAIS and conclude that the EAIS is slightly negative. Velicogna 2007 concludes that it is in balance, but Chen 2009 (another one i forgot to mention) is the most recent study and shows that since 2006 the EAIS has been losing ice extensively at -57 Gt per year. Based upon my assessment of the literature, the EAIS was in balance or slightly positive during the 1990s, balance or slightly negative during the early 2000s and extremely negative since the early 2000s. This goes hand in hand with thinning occurring on cook and totten glaciers in EAIS according to Shepherd and Wingham 2008…
You can accuse me of intellectual dishonesty all you want but I have made a legitimate effort to prove my case and to show that the literature and evidence supports my conclusions. Where is your evidence? I think that until you research a little bit more into this subject you should stick more to your specialties.
David says:
June 30, 2010 at 6:12 am
“Secondly, uncertainty in absolute measurement isn’t the same as uncertainty in relative changes. This is a well-known situation in measuring temperature, where we can’t be sure of the exact temperature, but we can measure changes (or anomalies) with great precision.”
David: It is also true that the variation of changes can range all the way from zero (the best case for precision) to being equal to the pooled estimate of the variation of the original measures which gave rise to the computed change. Also, in any statistical comparison, the sample size associated with the test statistic, which is used to calculate degrees of freedom for the comparison, is 2xn for the raw data and only n for the change data. One must have all of the raw data in hand before any conclusion about “precision” and the effects of using “changes” can be reached.
Robert,
Looking at the mass component of sea level rise as determined from Grace, I assume that the effect is primarily due to ice loss from Antarctica where 90% of the land ice is.
http://www.argo.ucsd.edu/global_change_analysis.html#temp
However, the graph from the above ARGO site clearly shows that sea level rise from positive mass gain is in the fall when I assume that the glaciers in antarctica are likely surging after gaining weight from the polar winter. In the spring at the end of the polar summer there appears to be a drop in sea level or a mass gain on the continent?
It seems to me that surging glaciers is not a sign of retreat due to warming seas but rather due to increased mass developed over the polar winter. Can you explain?
Robert and David,
Do you have a link of a study/proof of the stability ind time of the underlying planetary gravitational fields?
This is my third post where I stress that measuring differences in height and accelerations of these differences may have a gravitational input G1 from diminishing ice, and G2 from isostatic changes because of diminishing ice, but what is being quoted ignores G3, which is the field coming from the bulk planet, huge in mass with respect to the surface effects measured, and where we know there are tectonic and magma motions that move masses and change densities that are much higher than the density of H2O as ice.
I have not seen anybody addressing this problem, of too many unknowns for the data given. What is coming out of the fits is G1+G3, and I see no way of disentangling them except hand waving.
That G3 is large is evident in the geoid given by GRACE, http://earthobservatory.nasa.gov/Features/GRACE/page3.php where changes are not isolated on the antarctic.
A truthful analysis would be to give the maps for the whole globe, not interpreted as ice, but as gravitational changes. There is no physics reason that gravitational changes will be isolated in the other tectonic plates and leave the antarctic plate to play with the ice only.
So before flooding us with more of the same behind pay wall references, why don’t you give a link where this gravitational question is explained?
This is outright falsehood, FTA:
“..that the East Antarctic ice sheet-home to about 90 percent of Earth’s solid fresh water and…”
Uh, no. Antarctica as a whole is home to about 90 percent of Earths’ solid fresh water, not just the east side. The way this was phrased it cannot be excused as bad wording, that’s a lie.
Steve, I’m afraid you are the one who did the dishonest reporting in this article. David and Robert are correct.
I also believe you understand the factors behind changes in mass balance of glaciers and ice sheets but purposely chose to ignore those in order to once again try to discredit any science showing loss in the mass of ice on the planet. From your incessant use of PIPS2.0 it is clear that you only believe in science or models when it suits the point you are trying to make. The reality is there are declines being observed in ice on the planet no matter how hard you try to mislead others less well read on the subject.
David with regard to your comment
“Anthony Watts, this isn’t the first post by “Steven Goddard” displaying a woeful lack of regard for basic research or fact-checking. Continuing to post his “insights” will damage your credibility. Does this concern you?”
Don Easterbrook has posted a comment largely supporting Steve’s post.
I would be interested in hearing your opinion on his knowledge on the subject of glaciology?
Robert says:
June 30, 2010 at 5:19 am
Robert, Steve doesn’t have any evidence countering yours. And I wouldn’t expect him to even attempt to give counter evidence. After reading several of his posts, it seems his tactic is repeatedly to mislead people. I think there are other article authors on this site that are more honest in their reporting, Willis recently did one that was just a basic reporting of the science w/o putting in a bunch of conclusions or inflamatory statements and that was much appreciated, but Steve doesn’t seem capable of doing that.
latitude says: June 29, 2010 at 7:17 pm
I wish these nut jobs would put half this much time, money, and effort into at least trying to do something worth while……………
I completely agree, and so many visitors to this blog say exactly the same thing!
If the total of land-based ice is diminishing then total seawater must be increasing at an increased rate. Is it? And why should humans worry if it is? Globalisation and technological growth is making more of the world’s barren land practically inhabitable and therefore, fuctionally speaking, there is more good earth for humans to flourish on than ever.
Steven Goddard:
Are you not aware that it is possible for the ice to gain mass in one place, while at the same time losing it in another place? The results from GRACE show the net change, which is, as you can see but refuse to believe – negative.
So, the fact that the ice is depleting while snow is being added merely means that the actual loss rate is even greater than the figure derived from GRACE.
The added snow, on the other hand, is yet another sign of warming. Is this confusing? It confused many people on this blog last time the subject came up. Don’t you have some experts on the subject? Climatologists, or something?
PS: Smokey – I believe facts are important. If this means spending time to get things right, then I find the time or remain silent. But if it’s just a matter of reading the referenced source and discovering that it has been misreported, then that’s not hard, is it? Basic scepticism demands that people should check what is being said. When I discover that “Steven Goddard” is not being accurate, then I lose faith in anything he has to say. NASA, on the other hand, have a good track record with discovering and correcting mistakes.
I prefer to get my science from scientists, not anonymous, unpublished bloggers.
Glaciers calve more ice off into the ocean when they are receiving more snow in their interior.
Increased glacial flow is normally a sign of an expanding glacier. Decreased glacial flow is a sign of a retreating glacier. When a glacier disappears, glacial flow drops to zero.
Here is another Nature article which disagrees with the GRACE map about ice loss in the interior of East Antarctica.
http://www.nature.com/news/2008/080113/full/news.2008.438.html
“Antarctica: gaining weight in the middle, but losing more at the edges.”
Game, set and match to Robert
jeff brown
Your ad hom attacks are getting incredibly annoying.
If you have a specific objection, state it clearly. You appear desperate.
David
Again, this article is about East Antarctica. Please don’t waste my time changing the subject.
Fred windsor
Do you have anything intelligent to add to the discussion? Your crew is completely incapable of staying on topic.
Phil,
What part of this sentence isn’t clear to you?
“Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing.”
Perhaps I am assuming to much in expecting that commentors have basic map reading skills?
So both Robert & David make excuses for not submitting their own articles, and continue to take their pot shots at Steve Goddard — who steps up to the plate with several new articles a week.
Anyone can be a critic, and that’s what these two are doing: looking for any possible opportunity to criticize — while admitting they don’t personally have what it takes to write an article. At the very least, they could emerge from their mom’s basement long enough to answer anna v’s comments.
Decreasing temperatures at higher elevations of a glacier can also cause reduced flow, because the viscosity of the ice increases at lower temperatures.
Ryan says:
June 30, 2010 at 7:05 am
“… if the ice is reaching the ocean faster, why would the absolute temperature make any real difference? The ocean is significantly warmer then the melting point of the ice and therefore ANY ice at ANY time reaching the ocean will be forced to melt – this is always going to be the case regardless of its absolute temperature. ”
“Secondly, even if the ice in glaciers close to the ocean were to melt entirely the ice further inland will not readily reach the sea since it is effectively locked to the terrain beneath it.”
You are incorrect with your first point. Ice melts quicker in warmer water. If you put an ice cube in a warm glass of water it will melt quicker than in a cold glass of water. Also note that the oceans around Antarctica are in many regions very close to the melting point and might otherwise have become ice if it were not for the currents/salinity and other oceanic reasons. I myself have been there and seen measurements of water which is below 0 on numerous occasions. Also consider that warmer oceans eat away at the bottom of the glacier causing it to thin and subsequently move quicker.
Your second point is absolutely off the mark. Glacier ice inland is very dependent on the outlet glaciers particularly in West Antarctica. The WAIS is for the most part grounded below sea level and sloped towards the interior, meaning that water can penetrate deep inland in West Antarctica in these deep basins and can begin to eat away at the bottom of the ice where it meets land. This process ultimately leads to grounding line retreat and floatation of ice which is above the penetrating water. Grounding line retreat in the Amundsen Sea Embayment is particularly important because the subsequent glacier accelerations have been seen to have propagated far inland. Furthermore, because the deepest parts below sea level of the WAIS are at the center of it, this means that grounding line retreat theoretically wouldn’t stop until it reaches that topographic barrier.
All in all Ryan, I think it is time you start looking up some of the glaciological principles for Antarctica before you make assumptions that you cannot support.
One Final note, unlike mentioned in your statement, precipitation in west antarctica is quite high. And your final comment… there are many factors which determine regional glaciations including precipitation, elevation, temperature, shading and so on… Ice being lost in Antarctica does not mean that ice has to be lost elsewhere. But for the record, the alps have lost ridiculous amounts of ice…
Vincent says:
June 30, 2010 at 7:07 am
“Robert,
you make some interesting technical points. However, I’ve always taken ice extents from cryosphere today, and they show a positive anomaly for the SH. Yet you seem to be claiming the opposite.”
This discussion is not about Sea Ice Extents but rather Land Ice. It’s a common misconception to call all ice the same. For your future knowledge the Arctic Ice Cap is Sea Ice, Greenland Ice Sheet is Land Ice, Antarctica is covered in Land Ice with Sea Ice around it. Land Ice is what significantly contributes to sea level rise. Hopefully this helps to clarify your confusion.
Smokey
I have no objection to criticism. What bugs me is people setting up straw man arguments, and then repeating them over and over again.
No one has made any attempt to justify the GRACE image showing ice loss in the interior of East Antarctica at -30C, which is what I wrote about. They go blathering on endlessly about other regions of Antarctica.
Finn:
The entire trend over the region can be encapsulated by the error bars. There is therefore no ability to statistically suggest one trend over another trend for the whole data set to the degree for which it remains coupled. A set of +/-3°C for .1°C change is more than likely coupled across the whole set: There can be no defensible trendline for this data set.
Now if the data became uncoupled, that is, there is some point at which the error bars of an identifiable set of the data moves outside of the error bars of another set of the data, a trend can be drawn between these points, but you treat both populations as single data points. Also, situations of such small change relative to the amount measured typically do not uncouple without observable events that cause that uncoupling at particular points in the time distribution of the data set, IE, before and after a meteor strike or before and after the resiting of a thermometer or before and after the polar bear ate the tagged penguin.
This trend vs. error is simple hackery.
Smokey says:
June 30, 2010 at 10:24 am
“So both Robert & David make excuses for not submitting their own articles, and continue to take their pot shots at Steve Goddard — who steps up to the plate with several new articles a week.”
“Anyone can be a critic, and that’s what these two are doing: looking for any possible opportunity to criticize — while admitting they don’t personally have what it takes to write an article. At the very least, they could emerge from their mom’s basement long enough to answer anna v’s comments.”
Submitting their own articles where? Like where is this grand mecca of article submission to which you refer? First of all there are plenty of good articles out there so why do I have to submit any. Skeptical Science does a great job with the Antarctic work so do they need someone else to try and do the same? Secondly, I have a full-time job and am working on my own thesis research on the side. I felt like taking time out of my day to help some people get better informed on the state of glaciological research in Antarctica and you jump all over me as if I’m a coward. I think what’s important is that people find out the facts with respect to all this and not that the second one of the guys on your team is disproved, that instead of learning and moving forward in a constructive manner, you sit back and criticize me for having the gall to not want people to leave here misinformed?? With respect to Anna V’s commentary, I haven’t seen it but I will now search her name and try to address it when I get off work in 2 hours.
stevengoddard says:
June 30, 2010 at 10:24 am
Phil,
What part of this sentence isn’t clear to you?
“Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing.”
Perhaps I am assuming to much in expecting that commentors have basic map reading skills?
More snark from you as expected! Yes you had a couple of sentences about the East Antarctica but your original post was not exclusively confined to that region.
Did your forget this?
In 2007, NASA generated this map (below) of Antarctica showing just how hot it is getting down there in the land of Penguins.
Or this?
Assume for a minute that we accept the GRACE numbers. The first problem is Antarctica contains a lot of ice : 30 × 10^6 km³. At 100 km³ per year, it will take 300,000 years to melt.
Or this?
The hot red map above was preceded by a cold blue map which showed Antarctica getting cooler.
Or this?
NASA justified their heating up Antarctica with this comment :
And this:
I overlaid the Antarctica summer temperature map on the GRACE “melt” map, below. As you can see, GRACE is showing ice loss in places that stay incredibly cold, all year round.
Finally:
This article is about East Antarctica, and you are referencing studies and data which include West Antarctica.
As did you, so what the hell are you complaining about, you have no leg to stand on!
David says:
June 30, 2010 at 6:12 am
Dave I know Mr. Goddard can defend himself but perhaps you missed this statement. This is what the entire post was about to me.
“Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002” and that “if all of this ice melted, it would raise global sea level by about 60 meter (197 feet).“
As Mr. Goddard, said it will take 300,000 years for this to happen. We all know and I am absolutely sure Mr. Goddard knows all the ways ice can and does melt. This is a grandiose statement for no reason other than to grab attention. NASA should be ashamed.
Further, I wouldn’t use the idea of not knowing the absolute but knowing with precision the change as a defense to a cop in a speed trap. “But officer I know I was within .05 mph some speed close to 65mph.” said Dave.
Mr. Goddard’s post was readable and enjoyable. For that alone I am thankful.
Phil
I wrote exactly four paragraphs about GRACE, quoted below. There is no mention of anything other than East Antarctica. I challenge you to attempt to stay on topic and find anything incorrect that I wrote.
If your “science” depends on promoting BS, it is a waste of your time. Why would you cling to it?
Phil,
And before you embarrass yourself, the “places that stay incredibly cold, all year round” are in East Antarctica.
http://climateinsiders.files.wordpress.com/2010/06/800px-antarctic_surface_temperature.png
stevengoddard says:
June 30, 2010 at 10:34 am
“I have no objection to criticism. What bugs me is people setting up straw man arguments, and then repeating them over and over again.
No one has made any attempt to justify the GRACE image showing ice loss in the interior of East Antarctica at -30C, which is what I wrote about. They go blathering on endlessly about other regions of Antarctica”
Take a look at Figure 1 of this paper (Allison et al. 2009, Ice Sheet Mass Balance and Sea Level) (Antarctic Science 21(5), 413–426 (2009))
Notice anything similar between your ice mass losses at the interior of Antarctica and this figure? Every region of the EAIS that shows loss is also in a region where fast moving ice streams penetrate deep into the EAIS and travel out to the coast at velocities of between 100-500 m per year according to this figure (the figure is older though). If velocities on these ice streams accelerated then that would explain your mass losses. Furthermore, as previously pointed out, Totten and Cook Glaciers (Both in EAIS) saw large thinning which causes glacier accelerations. Both these glaciers are in submarine basins similar to Pine Island Glacier and thus allowing for effects to propagate inland more.
There, now can we get back to the part where you admit your analysis was faulty?
Anna v asked about the hydrologist working on glaciers in the dry valleys. That was Trevor Chin who also spent much of his life analysing the decline of the NZ glaciers.
Off topic but probably interesting
Lake Vanda is unusual in that it has 3 m of ice on top but the bottom of the lake is 25 degrees Celsius. This occurs because during ice ages the summer melt ceases and the lake level drops due to sublimation. This concentrates the salts in the lake to produce a very toxic saturated solution which is very high in calcium choride (some small lakes are still liquid at -60 degrees).
When the climate warms again and the summer melt (which only lasted 6 weeks in 1985) starts, the fresh water layers on top of the concentrated salt solution which prevents thermal mixing of the fresh water with the older salt layers. While there is some mixing , there are two distinct layers the upper one being lower concentration than the lower one. The result of later cold period that was not as long as the main one.
The salt soutions have been analysed by Dr Torre (Japan) but I dont have the data to hand. One of the experiments the hydrologist tried was to determine the sediment being dropped by the ice as the surface ice thinned over summer. they lowered inverted umbrellas on 3mm stainless steel cable to near the bottom. When they pulled the cables up some weeks later some of them had corroded through- pwerful mix down there.
Ignore for a moment that sea surface temperatures are well below normal around Antarctica and that sea ice extent is at a record high for the date.
Let’s play the alarmist game and assume that all ice in regions which get above 0C in summer melts over the next 100 years. That is less than 1% of the Antarctic ice mass.
In other words, it is too cold over 99% of Antarctica’s ice mass to ever see any melt. The Antarctica melting scare is nothing but pure, unadulterated BS.
Robert says:
“…now can we get back to the part where you admit your analysis was faulty?”
First, I’d like to know how I can get a job like Robert’s — where I can repeatedly write, lo-o-o-o-ng, detailed critiques during my working hours.☺
This may or may not be a salient point, but, if we consider the fact that melting occurs in the antarctic primarily by sublimation into the vapour state, why is a fact of melting amounts then immediately directed to sea level rise? Water vapour in the atmosphere is not water in the ocean until it precipitates.
Robert,
GRACE shows ice loss more than 700 km from the coast. The Science Daily article says “may have begun to lose ice” which implies (unambiguously) that this is a recent event.
Now, using your estimate of 100-500 meters glacial movement per year towards the coast, it would require between 1,400 and 7,000 years to propagate a response 700 km in the interior.
In other words, if the interior of East Antarctica is losing ice, it is in response to changes in ice movement near the coast which occurred thousands of years ago.
I just proved my own point Goddard. See Extensive dynamic thinning on the margins of the Greenland and Antarctic Ice Sheets by Pritchard et al. 2009. Nature Vol 461.
“In East Antarctica, we observe dynamic thinning on some outlets,
particularly between 90u and 165u E (Supplementary Figs 8 and 9).
Thinning of Totten Glacier, the highest-flux East Antarctic outlet, is
three times greater than previously reported28. The similar behaviour
of its smaller, independent neighbours indicates a common, regional
and perhaps ocean-driven cause.”
See Figure 2. You will notice that the coverage is a little sparse in the center because it is laser altimetry but that in EVERY location on your Grace map that shows mass losses in Antarctica, there is thinning occurring in coastal glaciers. This thereby confirms my previous hypothesis that the grace mass loss data is explained by thinning outlet glaciers causing accelerations.
Case Closed.
Robert,
Can we get back to the part where you admit that ice doesn’t melt below 0C, no matter how many times Al Gore or James Hansen repeats it?
http://www.physics.utoronto.ca/news_repository/will-oceans-surge-59-centimetres-this-century-or-25-metres
Smokey says:
June 30, 2010 at 11:39 am
Robert says:
“…now can we get back to the part where you admit your analysis was faulty?”
First, I’d like to know how I can get a job like Robert’s — where I can repeatedly write, lo-o-o-o-ng, detailed critiques during my working hours.☺
Luckily, GIS analysis often takes a lot of time with background processes running and such so one gets some free time while waiting for these procedures to finish. Its nice, well that is if you don’t mind sitting at computers frequently…
JDN: June 29, 2010 at 7:43 pm & Michale Cejnar: June 29, 2010 at 11:13 pm
An interesting concept. I wonder if Anthony and Steven have any opinions on using the law against those that misrepresent the science?
“Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing. How can you melt ice at those temperatures?”
Straw man. You very well can’t melt the ice, but the ice isn’t melting at that location, and that’s not what the authors of the paper are claiming. Most of the regular, annual ice loss is due to calving, NOT melting.
“it is too cold over 99% of Antarctica’s ice mass to ever see any melt. ”
Yes, and I don’t think, barring any quibbles over an exact proportion, that the authors, or NASA, or anyone else, is arguing that.
Accelerated ice flow at the ice shelf/terminus would reduce the ice thickness at an upstream location, if accumulation remained constant. It’s like grain flowing out of an elevator and into a hopper – the grain level drops. Warmer ocean waters and terminus surface temperatures certainly can cause accelerated mass loss and accelerated flow, but so can a lot of things, like increased wave action. It’s not so much the melting as it is the mechanical stress on the ice shelf (though meltwater wedging into cracks in the Larson B ice shelf certainly were a factor in its collapse). If you’ve got compressed ice flowing into a terminus, the stress due to expansion is greater in a warmer environment, even if it’s still below freezing. That further undermines the structural integrity of the ice shelf, and can accelerate the calving rate – which controls the flow rate of the ice!
The authors of the paper did not do an attribution study, they just identified and studied the mass balance changes. The locations in East Antarctica that show a negative trend in ice thickness are upstream of their outlet to the ocean. Refer to (http://www.fas.org/irp/imint/docs/rst/Sect16/map+.jpg) for a nice map of flow rates.
“The problem with GRACE is that it measures gravity, not ice. Changes in gravity can be due to a lot of different things beneath the surface of the ice. Antarctica has active magma chambers. Plate tectonics and isostasy also cause gravity changes.”
I agree. The authors of the paper also agree. They removed a number of atmospheric, oceanic, and geologic signals from the GRACE measurements, and took into account post-glacial rebound of bedrock, among other things. They are cautious in their discussion of errors and uncertainties.
I suggest reading the actual paper rather than just the Science Daily article.
Robert
You appear to understand very little about the properties of ice, particularly at extremely cold temperatures.
The viscosity of ice at -30C is extremely high. Imagine an ice cube in the deep freeze that is 700 km long and 3 km thick. Do you think that someone standing at one end of the ice cube will quickly become aware of melting at bottom of the other end?
Again, it would take thousands of years for the opposite end to see any effect.
People who make statements like “case closed” are revealing their lack of intellectual skill and their own closed mind.
“”” jorgekafkazar says:
June 29, 2010 at 8:03 pm
Johannes Rexx says: “You don’t have to melt ice to reduce its quantity. Ice will sublime directly into water vapor when it’s cold enough, the winds are strong enough, and the effect lasts long enough.”
Wrong. Cold ice temperatures reduce sublimation. “””
I believe it is also necessary to have the atmospheric relative humidity be low compared to the saturated vapor pressure at that Temperature. Th esnows of Kilimanjaro for example, are believed to sublime because changes in the forestry on the plains around the mountain; as in cutting the trees down over thousands of years; have resulted in lower levels of humidity in what used to be a tropical rain forest region. So a lack of precipitation on the mountain and low relative humidity up there is why the snows sublime.
Given that that spot in East Antarctica where they now say isce is being lost, is adjacent to a whole lot of ocean water including surface waters that are warmed by tropical currents coming south. So I would not expect that East coast to be so arid, as to promote a whole lot of sublimation from the ice; although some is possible at times, I would suspect.
These sorts of studies seem to be carried out by the same sort of researchers who report that if you cut all four legs off a frog; they are rendered stone deaf; and will not jump, no matter how loud you yell at them.
all this ice has been lost, but as the sea levels havn’t risen by 60m we must suppose it hasn’t melted , so where is it?
Nick Davis
Hansen most certainly is quarreling over that.
http://www.physics.utoronto.ca/news_repository/will-oceans-surge-59-centimetres-this-century-or-25-metres
Most of East Antarctica is considered to be desert, from wikipedia;
http://en.wikipedia.org/wiki/Climate_of_Antarctica#Precipitation
http://upload.wikimedia.org/wikipedia/en/7/7f/File-Dgv-surfbal-1.gif
The total precipitation in Antarctica, averaged over the entire continent, is about 166 mm (6.5 in) per year (Vaughan et al., J Climate, 1999). The actual rates vary widely, from high values over the Peninsula (meters/yards per year) to very low values (as little as 50 mm (2 in) per year) in the high interior. Areas that receive less than 250 mm (10 in) of precipitation per year are classified as deserts. Almost all Antarctic precipitation falls as snow. Note that the quoted precipitation is a measure of its equivalence to water, rather than being the actual depth of snow. The air in Antarctica is also very dry. The low temperatures result in a very low absolute humidity, which means that dry skin and cracked lips are a continual problem for scientists and expeditioners working in the field.”
Looks like desert to me.
Robert,
“Hopefully this helps to clarify your confusion.”
Yes, that makes sense now. Thank you.
Robert
NONE of your “evidence” is solid. All the papers you quote say”may” could” might” its possible”. That is not evidence, it’s guessing.
Can anyone see any substantial Arctic ice loss for June of 2007, 2008 and 2009?
Didn’t think so. But for those who are inclined to panic over completely natural, routine climate fluctuations…
…carry on.
stevengoddard says:
June 30, 2010 at 5:27 am
Robert
Suppose there had of been a recent increase in ice movement near the terminus of the glaciers. It would take hundreds of years for that to be expressed as changes in ice thickness 1000km away, as is claimed in the GRACE maps.
Ice at -30C is extremely high viscosity. If they dig a hole in the ground a mile away from your house, does it change the elevation of your house much?
_________________________________________________________________
Oh there is an INCREASE in ice movement…but it is CAUSED by Volcanoes
Map showing the Antarctic plate (blue) and volcanic activity (red)
“… It is no mistake to call Antarctica a land of “fire and ice,”
…In 1993, a team of geophysicists noticed a round depression, about 6 km (4 miles) wide and 50 m (160 ft) deep. The only thing that could melt so much ice in a round pattern, they reasoned, would be a volcano erupting under the ice. Sure enough, radar revealed a 650 m (2,100 ft) high volcano – sitting in the middle of a huge volcanic crater 8 km (14 miles) wide. Although erupting volcanoes don’t provide nearly enough heat to melt the icecap, they do melt the base of the sheet, providing lubricant for the rapid movement of ice streams and glaciers (see Continental Ice). “
(Thank you for the link Mr. Barry Day)
Nick Davis
The GRACE map shows ice loss 700km from the coast. Do you see any ocean 700 miles in the interior of East Antarctica?
How long do you think it takes a glacier to move 700km to the coast at temperatures ranging between -30C and -80C? You are the one creating the straw man, and it is pretty annoying.
Deal with it. There is no way that the gravity anomaly GRACE shows in the central portions of East Antarctica has anything to do with human influence on the climate or AGW or CO2.
Smokey says:
June 30, 2010 at 1:13 pm
“Can anyone see any substantial Arctic ice loss for June of 2007, 2008 and 2009?
Didn’t think so. But for those who are inclined to panic over completely natural, routine climate fluctuations…”
Funny how you show June and not the sea ice minimum in september. Cherry picking sounds like fun!
stevengoddard says:
June 30, 2010 at 3:14 pm
“How long do you think it takes a glacier to move 700km to the coast at temperatures ranging between -30C and -80C?
Deal with it. There is no way that the gravity anomaly GRACE shows in the central portions of East Antarctica has anything to do with human influence on the climate or AGW or CO2.”
Where is it you see the ice loss in the center of the EAIS. From the figure showed above it is clear that the ice losses are occurring in regions close to the coast and close to the large ice streams which propagate far inland. You still didn’t look at the Allison et al. 2009 article apparently because you would see where the major ice flows are and they correspond with all the mass loss areas on your map. Secondly, no one made the argument that these changes are instantaneous and accelerations could be responding still to the warmth of the 1990s as ice sheets tend to have slow response times. Although this theory has been challenged of late with the instance acceleration of buttressed glaciers feeding Larsen A and B (Scambos et al. 2004).
Finally, the ice at the surface may be extremely cold but don’t you realise that thicker glaciers tend to be warmer at the bottom due to the amount of ice insulating it. Oftentimes thick glaciers create their own basal lubrication because of the insulation at depth. This is also clear based upon the existence of subglacial lakes in certain regions (Glaciers and Glaciation, Benn and Evans, 1998?)
Despite what you say, inland propagation can occur very quickly, especially with grounding line retreats. Evidence for that is shown in Rignot et al. 2005, Scambos et al. 2004, Pritchard and Vaughan 2007, Schoof 2008.
“Goddard says: Can we get back to the part where you admit that ice doesn’t melt below 0C, no matter how many times Al Gore or James Hansen repeats it?”
You still don’t understand how Antarctic ice losses occur. It has nothing to do with surface melt but rather calving and glacier acceleration. Until you acknowledge this any further forays into this topic represents a lost cause on your part.
Robert
Someone says
“NONE of your “evidence” is solid. All the papers you quote say”may” could” might” its possible”. That is not evidence, it’s guessing”
Just because researchers have the foresight to not say things with absolute certainty does not make it guessing. Guessing is what Goddard did with this analysis here. What they did was a large study that gave them an answer and they presented the answer with its uncertainties included. Are they supposed to say its absolutely 100% guaranteed or something? Then you’d be complaining that they are being ridiculously cocky. Secondly, many of the papers do have words like may and such but many also have concrete numbers and detailed measurements. Funny how you choose to ignore the actual basis of the articles and just read the abstracts. Thirdly, you find a way to measure ice changes without any uncertainty! I’m waiting…
Is this a net loss after accounting for any gains?
yet!!! Is this scientific language? Is this a promise concerning Grace’s possible tweaking in future? It’s as if they know what the future will bring. Only time will tell but I think this is a non-story bearing in mind Antarctica sea ice is at a near record high.
http://tinyurl.com/iceup43-nsidc
1980 2009
Sea Ice Extent 3.5 5.0
Sea Ice Conc 2.0 2.9
Case Closed.
I have to go now, on vacation fishing for 5 days. Just gonna summarize a bit. Goddard argued that the pretty close to the coast mass losses (which he calls central? point out the central part on a map??) of ice cannot in reality be real based upon temperatures in the EAIS as a whole. I showed using Allison et al. 2009 paper that fast flowing glaciers in that region actually originate in the coast and are fed by the very regions which Goddard claims have unwarranted losses. I provide the theory that this is due to increased thinning at glacier termini’ resulting in glacier accelerations which increase the mass discharge through the ice streams and thus cause a mass loss in the region. To supplement this, I use Pritchard et al. 2009 to show that the termini for the glaciers to which I referred to and which Goddard referred to, have all showed extensive thinning on their margins. This evidence provided a mechanism through which glacier acceleration could occur. Finally I argued based upon evidence from numerous studies (look at my other posts if you want) that this thinning of glacier termini is the result of warming ocean temperatures eroding away outlet glaciers causing an inland propagation of the surging.
So you can all decide what you like in terms of this argument but it is certainly clear that the evidence supports my conclusions as per other glaciological investigators.
In conclusion. It has been shown that Goddard did conduct with due diligence with respect to this analysis as he compared air temperatures in antarctica to mass losses despite having been told numerous times and having been given evidence over and over that Ice losses occur because of ocean warming, glacier termini thinning and glacier accelerations.
It is a shame that Goddard has chose to ignore the real issue that his original comparison was flawed and I believe that a revision is required if he wishes to keep his credibility for future glaciological interpretations.
Ultimately that is his choice in the end but I think it has been proven to him that glaciers in antarctica are thinning, accelerating and causing extensive mass losses across the WAIS and the EAIS. If he wishes to argue against this by pulling out old papers (again) then he can. But we all know that newer papers by the same authors show these losses because of more advanced techniques than low resolution radar altimeters. It should also be noted that there is a plethora of books and papers on these subjects and that if time was taken, more appropriate analysis techniques could be used. I suggest that Goddard either put up the evidence that refutes papers such as the Allison et al. 2009 and Pritchard et al. papers or take down the article until it has been revised to represent a true evaluation of the science. Arguing for the sake of arguing benefits no one.
AC1,
Sea ice and Land ice are not the same thing. Get educated before making statements like “case closed” when you clearly don’t even know the difference between the two. I used it previously and I think it was inappropriate but at least I was presenting an effective argument on this topic. You are showing irrelevant data for a land-ice discussion.
Robert
What complete garbage you just posted at 4:34.
I wrote :
“But why are we looking at temperature trends anyway? The real issue is absolute temperatures. Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing. How can you melt ice at those temperatures?”
There is only one part of Antarctica which has -30C temperatures in the summer, and it is right in the center of East Antarctica at elevation in excess of 10,000 feet.
http://climateinsiders.files.wordpress.com/2010/06/800px-antarctic_surface_temperature.png
You are apparently here to disrupt, not to have an honest conversation. Personally I think you should be banned from posting.
Antarctica “has been losing” 100 km^3 ice a year. So. Antarctica’s area =^= 13,000,000 km^2. That means it’s losing an average of eight millimetres depth a year. If measurements that small can be trusted – especially given caveats like that of anna v. And over what time scale? Anything even remotely like 30 years? Now Earth’s area =^= 510,000,000 km^2, ie 40 times the area of Antarctica. That means sea level rise of 8/40 mm a year or 2 cm a century.
It’s in this context that the misleading alarmist statement “if all of this ice melted, it would raise global sea level by about 60 meter (197 feet)” should be made illegal when stated out of context. IMHO.
But the problem with the material here seems to be worse than this. According to Cryosphere Today, Antarctic sea ice is up at almost a record high. So… is this article on GRACE akin to saying “the models predict different to the data… so the real data is not correct… here is your newspeak data… ” OK, now guessing that the time period measured by GRACE is pretty short, perhaps we have two Svensmark-type phenomena at work – (1) with the rest of the earth now cooling on balance, Antarctica is warming again – only fractionally but enough to cause a slight acceleration of glacier movement with most visible loss of mass in coastal areas – but (2) since the rest of the earth is cooling, the oceans included, the sea ice extent is increasing. Haha, but the orthodox don’t want any Svensmark explanations! certainly not two!
Robert,
I have been writing for three years, and you are the first person I have seen intentionally distort and lie.
I understand that is common practice on some other sites, but not at WUWT. You should go back to whatever Internet cesspool you normally hang out at.
“Now, using your estimate of 100-500 meters glacial movement per year towards the coast, it would require between 1,400 and 7,000 years to propagate a response 700 km in the interior.”
Does anyone really take you seriously?
Robert, here are some interesting issues about the Arctic ice loss.
2007 Arctic ice retreat due mostly to wind, currents – source NASA since then September ice has recovered. As for this September we’ll have to wait and see.
NASA says at least 45% melting since 1976 is most probably due to aerosols
In 2009 Polar 5 expedition found Arctic ice thicker than expected
Lets say the Arctic ice continues its alarming melt in September there is stil hope.
From NASA:
“So in addition to changing sea ice, we can kind of guess that something must be happening in the atmosphere over the Arctic, too.” Clouds are bright, too, and an increase in clouds could cancel out the impact of melting snow and ice on polar albedo.”
source
“Although sea ice and snow cover had noticeably declined in the Arctic from 2000 to 2004, there had been no detectable change in the albedo measured at the top of the atmosphere: the proportion of light the Arctic reflected hadn’t changed. In other words, the ice albedo feedback that most climate models predict will ultimately amplify global warming apparently hadn’t yet kicked in.”
“According to the MODIS observations, cloud fraction had increased at a rate of 0.65 percent per year between 2000 and 2004. If the trend continues, it will amount to a relative increase of about 6.5 percent per decade. At least during this short time period, says Kato, increased cloudiness in the Arctic appears to have offset the expected decline in albedo from melting sea ice and snow.” source
All this melting has been seen again and again and again and again in the past. This is why I’m not alarmed by even complete September ice loss or ice loss at the fringes of Antarctica.
Robert says at 11:48 am:
“Case closed.”
Sorry, Robert, it’s not ‘case closed’ until everyone agrees.
Now then, this statement of yours is especially silly:
“When you see accelerated mass losses like in Antarctica, it is due to increases in glacier velocity without subsequent increases in input ice.”
Your glacier conjecture doesn’t answer a central question: why is the sea level not reflecting all this increasing glacier ‘velocity’? Antarctica is a continent. If it is losing such a large volume of ice that isn’t being replenished, then the sea level rise should be accelerating. It’s not.
Try limiting yourself to real world observations, Robert. Why? Because your models suck. And they’re leading you down the wrong path. Observations, me boy, that’s science. Models are only conjectures.
From AC1s’ short comment how do you know AC1 does not know the difference? I’ll not accuse you of being a mind reader but I am baffled as to how you came to that conclusion.
In the interest of unbiased research, does NASA ever report on a cooling trend?
Smokey says:
June 30, 2010 at 5:09 pm
” Sorry, Robert, it’s not ‘case closed’ until everyone agrees. ”
Truth isn’t based on consensus. Regardless, I could provide an absolutely pivotal evidence that proves my point (like I have) but it wouldn’t change your minds. When your mind is made up, it is made up, regardless if facts get in the way…
There were portions of the sea level rise which were unaccounted for. In the IPCC AR4 they had estimates that Antarctica was gaining and then had some sea level rise left unaccounted for (look it up!). The ice losses are just increasing our knowledge on what is causing sea level rise. Personally, I think that Because oceans aren’t currently warming at the rate they were over the last 20 years that the amount of sea level rise due to thermal expansion may be reducing whereas the glacier losses are increasing… Pure speculation afterall. I’d have to take a little time to read the literature on the topic but due note that we’re talking only a contribution of around 0.5 mm per year but that rate is accelerating so that is the importance of it. Finally, all the papers I cited are not models, they are measurements using different techniques. Is a laser measuring the distance between the sensor and the ground over the course of a few years a model? (Pritchard et al. 2009). Lets get real on this subject. Those modeling accusations may have some validity for other fields but measurements and real evidence support the Glaciological interpretations by glaciologists. If you don’t believe it then try it for yourself. For the record I’m working on a paper about overestimation of ice losses because of statistical problems with some elevation models used for alpine glaciers, really the mark of an AGW fanatic who is bending the truth isn’t it? Most glaciologists just do their job and stay out of the political side of things so lets stay away from conjecture on whether we do real world observations… If a glaciologist were claiming Antarctica were gaining mass you would give him a microphone and call him credible. Yet all the papers and researchers I presented are referred to as theoretical modelers away from real world observations. I made no attempt to call losses because of AGW and yet look at the fight I received? Open minded appraisal of the literature is important for all, skeptic or proponent.
This is what Robert calls “close to the coast.”
About the same distance (700 km) between Los Angeles and, or Tucson, Arizona. Perhaps he should purchase some beach front property in Tucson?
He also claims that changes in glaciers would quickly perturb other parts of the glaciers 700 km away, which indicates that he does not understand glacial movement – at all.
Conclusion – he is probably a government glacier expert.
Robert also believes that it makes sense for sea ice to be expanding at warmer lower latitudes and elevations, while glacial ice is disappearing a colder higher latitudes and elevations.
More evidence that he is probably a government expert.
Chris Noble
I am assuming (perhaps incorrectly) that you made it past 3rd grade, and know how to divide 700km/100 (meters/year) = 7000 years
AC1 I think you got Robert running scared there with your short but powerfull link and observation. Dismissing your point like that is a sign of “no useful rebuttal”. :o)
I see perfect examples of confirmation bias from Robert and others. They see a paper that supports their view and quote it without a second thought. However, a paper that doesn’t match their bias is considered “old”. It’s absolutely hilarious to watch.
In less than 10 years we will see all of these papers discarded as short term observations because … that’s exactly what there are. Now, anyone who would consider these anything else says a lot about them.
Tell that to the IPCC and the folks at Real Climate. ;o)
“He also claims that changes in glaciers would quickly perturb other parts of the glaciers 700 km away, which indicates that he does not understand glacial movement – at all.”
For someone with such a patronising attitude you must have quite a lot of expertise in this area!
Have you actually asked a glaciologist about this? Or are you just relying on your ‘common sense’?
Don’t forget to sprinkle your paper liberally with Co2 induced warming comments if you want it to get past peer review or you wish to apply for any (future?) funding. :o)
Robert is claiming there has been an unexplained sea level rise. Like most of what Robert says, that is wrong. The sea level is rising in response to the planet’s natural warming since the LIA.
However, the rise in the global sea level has been moderating recently, contradicting Robert’s conjecture about those high velocity glaciers coming out of Antarctica.
Also, ocean heat is declining, not rising as would be expected with AGW. The IPCC’s models show ocean warming, while real world observations show cooling.
Robert likes to claim he’s won the debate [“it is certainly clear that the evidence supports my conclusions,” and: “case closed.”], but when observed facts are compared with his ‘evidence,’ it is clear that his evidence is based on computer models, which are only conjectures.
And since observations trump models every time, when Robert gets back from his fishing expedition I’m going to want first-hand observations of those 45-lb stripers he’s going to tell us he caught.☺
stevengoddard says:
June 30, 2010 at 5:33 pm
Robert also believes that it makes sense for sea ice to be expanding at warmer lower latitudes and elevations, while glacial ice is disappearing a colder higher latitudes and elevations.
More evidence that he is probably a government expert.
—————————————
Guess you still don’t understand what is driving the increase in sea ice. Seems you are too quick to jump on winds being the cause in the Arctic but completely ignore the winds in the Antarctic. I know you understand factors for glacial ice thinning, yet you completely choose to ignore them in this absolutely inane article.
Chris Noble
I have a geology degree and worked many years as a geologist. I have studied glaciers for many years. I also have an engineering degree and have a good solid understanding of material behaviour.
If ice thinned at the terminus of a glacier, it would be hundreds or thousands of years before that would have any effect on other parts of the glacier 700 km away – particularly at the very cold temperatures found at higher elevations of East Antarctica.
“I am assuming (perhaps incorrectly) that you made it past 3rd grade, and know how to divide 700km/100 (meters/year) = 7000 years”
The figure you are citing is the time for ice 700km from the coast to make the complete journey to the sea. This is not the same time taken for the effects to propagate up the glacier. If you open the outlet at the bottom of a grain silo it does not take hours before the grain at the top starts moving down.
Your combination of arrogance and ignorance is astounding.
Can you find a single qualified expert who agrees with your claims? A single paper? If you are going to contradict 100% of working glaciologists you should produce something other than your ‘common sense’ to support your claims.
Genesis 9:11 In the six hundredth year of Noah’s life, on the seventeenth day of the second month—on that day all the springs of the great deep burst forth, and the floodgates of the heavens were opened.
Does anyone find it strange that there is enough water in Antarctic to generate a 60m sea level rise? Not to mention that the ‘springs of the great deep bursting forth’ sound much like the active magma chambers and plate tectonics mentioned at the end of this article?
Sorry for the religious reference. I’m just sayin’.
“Your glacier conjecture doesn’t answer a central question: why is the sea level not reflecting all this increasing glacier ‘velocity’?”
Have you actually calculated how much 24 cubic miles per year would raise sea levels by?
Nick Davis says:
June 30, 2010 at 11:54 am
They removed a number of atmospheric, oceanic, and geologic signals from the GRACE measurements, and took into account post-glacial rebound of bedrock, among other things…
AKA free variables or fudge factors, all which are tuned to provide the desired results. not a sign of solid science IMHO.
Chris Noble
Your grain silo analogy is incorrect for quite a few reasons. The glacial sheet is 700 km wide by 3 km high. It is like a sheet of thin glass residing on a gentle slope. In Europe you can see windows which have flowed downwards over hundreds of years.
Antarctic ice (particularly at temperatures lower than -30C) is similar to glass, in that it is a very high viscosity liquid which flows slowly. Grain on the other hand behaves as a very low viscosity fluid. Every geology student understands the fundamentals of glacial movement..
The task for you is to stop appealing to authority, and start using your brain.
jeff brown
Downslope winds compress and warm. If it is cold enough to form sea ice at 70S, then it is certainly cold enough to keep freshwater ice at 10,000 feet at 80S.
The map shows this quite clearly.
http://climateinsiders.files.wordpress.com/2010/06/800px-antarctic_surface_temperature.png
“I also have an engineering degree and have a good solid understanding of material behaviour.”
Do you have anything other than your “good solid understanding of material behaviour” to support your claims?
Are you really trying to argue that it will take thousands of years before the effects of increased calving propagate upstream?
Chris Noble
BTW – I have cited two papers on this thread, which Robert chose to blow off
http://www.nature.com/news/2005/050516/full/news050516-10.html
http://www.nature.com/news/2008/080113/full/news.2008.438.html
Steve, do you not understand that at the bedrock it may be above 0C because the pressure of the ice causes temperatures to rise? Thus, your statement that it’s too cold for the ice to flow is entirely incorrect…
Steve, I looked at your links to Chris Noble, so now you’re talking about the entire ice sheet and not just the East Antarctic? Did you notice the map of where the ice is thickening and also the regions where it is thinning? So tell me, what is causing those regions of thinning you link to? yes we know temperatures are too cold for surface melting, so what is it?
Robert, in response to an enquiry from Smokey, you wrote:
Basically, she was pointing out that the Earths rock surface is dynamic but not “visible” under the Antarctic ice, or if you like, that there are more unknowns in gravitational and altimetry net values than there were available in the data or with technology at the time of various studies cited to date.
At the time of me writing this, you have not responded, so in order to assist you, here is her comment link:
Robert & David
Would you both please comment on this.
BTW; 1) Greenland is an interesting example of isostasy. It is depressed in the centre some 1,000m (?) below sea level under the weight of ice and the shoreline areas are still rising after the ice age. Antarctica appears to have much tectonic and volcanic activity, and notice in particular the geography of the peninsular aligned with similar in Patagonia; clearly a linked region of complex tectonics that is visible from space, including undersea.
BTW; 2) The ESA’s Cryosat2 launched last April is claimed to have the sophistication to give altimetry of ice surface and layers below. (replacing Cryosat1; failed on launch 4 years ago)
jeff brown
I did not say that it is too cold for the ice to flow. It is really bad form to misquote the author in the comments section.
chis noble,
What part of this is difficult to understand?
http://www.nature.com/news/2005/050516/full/news050516-10.html
jeff brown
My point is that places where GRACE supposedly shows thinning away from the coast, are probably misinterpretations of the gravity data.
Chris Noble
Good scientists have to be able to think for themselves.
stevengoddard says:
June 30, 2010 at 6:53 pm
Chris Noble
Your grain silo analogy is incorrect for quite a few reasons. The glacial sheet is 700 km wide by 3 km high. It is like a sheet of thin glass residing on a gentle slope. In Europe you can see windows which have flowed downwards over hundreds of years.
_____________________________________________________________
Your analogy with old window glass is incorrect.
Old glass is not what is called today as float glass.
The old glass was never flat to begin with due to the older less accurate glass making processes.
Glass exhibits no viscoelastic properties at STP.
http://en.wikipedia.org/wiki/Float_glass
This gets back to similar nonsensical rhetoric by Gore and others regarding Mt. Kilimanjaro.
They tried to say that ACGW was responsible for the beautiful snows of Mt. KJ etc etc.
Then it was found out that trees were over harvested and that allowed wind storms like never before and the wind melted the ice over the last 20 years in basic parlance.
I don’t know how the snows and ice of MT. KJ could have possibly been melted by ACGW evil beasts that we are since the ice line was never once above the freezing mark.
EFS_Junior
Your 7:58 comment was both pointless and incorrect.
Glass is a very viscous liquid, somewhat similar to ice at very cold temperatures. Do you think that glaciers are perfectly flat?
Chris Noble says,
Can you find a single qualified expert who agrees with your claims? A single paper? If you are going to contradict 100% of working glaciologists you should produce something other than your ‘common sense’ to support your claims.
100% of working glaciologists? oh please. A single paper? sigh.
Mr. Noble I’ll say this much for you, to come into someone else’s house and accuse a guest writer who has often proven himself in his writings as arrogant and ignorant you’ve got some courage.
By the way. Other than your sorry tired and well used red herrings and ad hominyms I didn’t see you refute a thing Mr. Goddard stated.
Mr Watts and Goddard are far more patient with foolish behavior than some of us, but if you are going to insult someone with Mr. Goddards background would you please bring more than your sandbox toys and your petty childish insults and use some real science please.
I didn’t see one piece of scientific evidence or scientific method in your comments, two things long forgotten by ACGW crowd along with manners and integrity.
stevengoddard says:
June 30, 2010 at 7:42 pm
jeff brown
I did not say that it is too cold for the ice to flow. It is really bad form to misquote the author in the comments section.
Mr Goddard you forgot slinging insults and slapping the author with red herrings, thanks to our ACGW visitors comments there is a certain lingering fish odor around.
I say Mr. Goddard, would you care to use some of manly vanilla spray to freshen up abit?
🙂
Chris Noble says,
Have you actually calculated how much 24 cubic miles per year would raise sea levels by?
Have you actually done any non-refutable studies that shows there is 24 cubic miles per year of ice melting from either Eastern or Western Antarcic?
Anything at all? Is there any paper anywhere on the face of the earth that has not been refuted and filled with more holes than the victims of the St Valentines day Massacre, that doesn’t have the very obvious word “probably” in it rather absolutely sure beyond a shadow of a doubt.
Are there any ACGW papers that haven’t been passed through the buddy system at Nature or Science that haven’t been shown to have numerous glaring mistakes like this issue Mr. Goddard discusses?
stevengoddard,
The glass in European windows has been shown not to flow in the way that you suggest. The bulges in the bottom are indeed due to low-tech glass-making techniques. Bryson got this wrong in his book, and then corrected himself in the online errata.
stevengoddard says:
June 30, 2010 at 8:16 pm
EFS_Junior
Your 7:58 comment was both pointless and incorrect.
Glass is a very viscous liquid, somewhat similar to ice at very cold temperatures. Do you think that glaciers are perfectly flat?
___________________________________________________________
Prove it, since you are argueing from the logical fallacy of appeal to authority.
Glass at STP is NOT a very viscous liquid!
It is a SOLID.
It is not a plastic and does NOT exhibit viscoelastic properties at STP.
I happen to be a Research Hydraulic Engineer, what are you? A blogger!
http://www.phys.ncku.edu.tw/mirrors/physicsfaq/General/Glass/glass.html
REPLY: Sir, you might want to reconsider your position. You are making an assumption on the person (Steve) about which you know nothing. I do, and I’ll tell you this bluntly. You are wrong. Now back to the science please and quit the personal attacks. – Anthony Watts
“BTW – I have cited two papers on this thread, which Robert chose to blow off”
Neither of which actually support your claim that it takes thousands of years for the effects of calving to propagate up glaciers.
Surely you can provide a reference for this claim. I hope you don’t expect people to believe something just because you say it is true.
stevengoddard says:
June 30, 2010 at 8:16 pm
EFS_Junior
Your 7:58 comment was both pointless and incorrect.
Glass is a very viscous liquid, somewhat similar to ice at very cold temperatures. Do you think that glaciers are perfectly flat?
___________________________________________________________
Glass is a solid at STP.
Glass is NOT a viscoelastic material at STP. Glass does not exhibit ANY viscoelastic properties at STP.
Glass is NOT a plastic.
http://www.phys.ncku.edu.tw/mirrors/physicsfaq/General/Glass/glass.html
“Your 7:58 comment was both pointless and incorrect.”
There is an urban myth that old glass is thicker at the bottom due to it being a high viscous liquid. This incorrect. As EFS_Junior points out the glass was never uniformly thick to begin with.
If you are going to pretend to be an authority on a wide range of subjects at least try to be correct on some of them.
http://adsabs.harvard.edu/abs/1998AmJPh..66..392Z
stevengoddard says:
June 30, 2010 at 7:48 pm
Chris Noble
Good scientists have to be able to think for themselves.
Excellent point Mr. Goddard and how refreshing.
Since the explosion of science heresy being put out by numerous scientists that supposedly are working towards solving a catastrophe moving our way, real science is the victim.
Two Hundred years ago if the actions Mr. Jones, Mann, and CRU et al. were to have happened, they would not still be sitting in their vaunted leather chairs in their ethereal ivory towers of academia, they would have been flogged, tarred and sent to the penal colony in New Zealand (sorry NZ’rs for the reminder of history).
The side of ACGW are trying to pontificate that if Steven Goddard’s writings (among others here at WUWT) have never made it to peer review and gone through Nature or Science then their work is garbage and they are morons.
When did Nature and Science peer reviewed journals replace the halls of Academia and proving to your peers (all of them not just the ones you agree with or have grants at stake with or to be published articles in pending status together).
When did published authors trump real scientists? Do I have a piece of paper on my wall that says ipso facto e pluribus unum that I am the great Wizard of Oz and therefore all must bow and listen to me?
No, but I have spent many nights, barely keeping my eyes open and learning things. Learning used to be the linch pin of science, not your bedarned journals, but learning.
Pride of proving something true or wrong used to be the bedmate of learning.
Do I have a parchment that has the word SCIENTIST next to my name? Does Steven Goddard or Anthony Watts or any of a dozen highly intelligent men or women that contribute to this blog? Some yes, many no.
However we all have one thing in common, compassion for learning, compassion for the right thing to be done, humility, and I would dare say a far far better grasp of the scientific method and what it means to society than most on the side of ACGW.
What ever happened to science for the sake of education, and the betterment of civilization?
“Good scientists have to be able to think for themselves.”
Good scientists do not delude themselves that they understand something that they clearly don’t.
Seriously, if you find that you are in disagreement with the vast majority of qualified experts in a given field it is a good indication that you need to reassess your understanding of that field. Just possibly you could be mistaken. Cranks on the other hand will assert that the vast majority of qualified experts are stupid or part of a conspiracy.
All I am asking is for you to provide some references that support your claims.
More appeals to ‘common sense’ do not suffice.
The thread trolls will do absolutely anything to change the subject and avoid discussing the fact that East Antarctica is too cold to melt.
I couldn’t care less if some prof thinks glass flows more slowly than some other prof does. The point is that it is a highly viscous liquid, like ice.
Mr. Noble and Junior,
Is it your intent as it is for far too many ACGW’rs to come here and sling red herrings about and totally ignore the most important discussion.
Why are you so hyper focused on the point of glass? Everyone knows that glass is no where’s near like ice. Old window glass used to lay on a bed of aluminum which caused pock marks and valleys based on its texture. What’s the big issue, glass is not ice move on.
Not once have you even lifted a finger to refute the fact that this article in question is using a satellite rendering based on gravity. The difference in gravity can be from any number of things that have not yet been pin pointed. That’s Mr. Goddard’s point pure and simple.
Throw all the red herrings you want and the room is going to smell foul but the glaring obviousness of his comments still stand.
Chris Noble
The only mechanism which can cause significant thinning of the glaciers at -30C is flow. We know the velocity which the glacier is flowing at. It is a simple calculation to approximate how long it would take for a change at the terminus to propagate backwards to the source of the glacier. I have done this calculation for you several times. I’m very sorry that you are unable to understand it. If you feel the need for additional help, you will have to seek that out yourself.
Brad
I have some very nice pieces of parchment next to my desk. But I have long since moved on from academia and research to actually accomplishing things in the real world.
In private industry, people are judged by their accomplishments.
“My point is that places where GRACE supposedly shows thinning away from the coast, are probably misinterpretations of the gravity data.”
The only support you have offered for this claim (which coincidentally fits your prejudices) is a further claim that the acceleration from increased calving cannot possibly propagate up the glaciers fast enough for this to occur.
Please do not appeal to your ‘solid understanding of material properties’ which apparently includes the urban myth about old window panes flowing.
Mr. Noble,
Would you care to look at Arctic ice as an example of your big red fallacy painted on the target of your wisdom?
How about glacier bay in Alaska. The majority of that ice started melting in the early 1700’s and has slowed drastically over the last 50 years. Did the ocean rise and Natives lose their lives? Please people. The basic truth of what Mr. Goddard has said is there, it’s true, it’s viable. It has been said by more than one person.
You sling your red herrings as fast as your arms can move but what have you done to prove him wrong? ABSOLUTELY NOTHING – zip.
There is no evidence to show that major calving of ice in either east antarctic or west. There is no real evidence to show that there is any major temperature rise anomaly.
I don’t know what makes me more frustrated the fact that I’ve wasted 40 minutes of my time, or the intentional attempts at subfuscation.
“Have you actually done any non-refutable studies that shows there is 24 cubic miles per year of ice melting from either Eastern or Western Antarcic?”
All papers are refutable if you have actual evidence that contradicts it.
So far nobody here has refuted the study that is being referred to.
Steven Goddard started with a complete red herring by making a big deal of the temperatures being below zero when the study never asserted that the ice loss was occurring through melting.
When it was pointed out that the ice loss was occurring through acceleration of the glaciers Goddard made some completely unsubstantiated claims that this was impossible.
“Smokey” joined in with another bogus claim that Antarctica couldn’t possibly be losing 24 cubic miles of ice a year because there would be a huge sea level rise. All I asked is for him to calculate the sea level rise that would occur from 24 cubic miles of ice.
There is an important distinction between skepticism and inventing bogus reasons to ignore studies with results that you find inconvenient.
Chris Noble
I will give a little help with the fluid flow problem. Consider two cases
1. A substance with nearly infinite viscosity. How long would it take to respond to change at the other end?
2. A substance with nearly zero viscosity. How long would it take to respond?
I’m not going to teach you a class in fluid dynamics, but you can at least be clever enough to observe that the blue spot is isolated – and that if it were the result of changes along the coast there would have to be a continuous region of blue all the way to the sea.
Chris Noble
The only thing bogus here is people who are not bright enough to recognize that ice is not melting at -30C.
The ridiculous stream of straw men, distractions, ad homs, off topic, mindless discussion here is genuinely sickening.
stevengoddard,
I have no real idea about this, but my guesses would be:
1.) Near zero time (although obviously still limited by things like, for instance, the speed of light)
2.) Near infinite time.
However, I would also imagine that it would depend on the forces involved. If there was a substance with low viscosity that was being subjected to great forces, it might very well move faster than a substance with high viscosity that was subject to much smaller forces – again, that is a guess based on not much more than intuition.
Although I just did a little experiment with a ruler, a fruit box and my wallet. As you increase the forces involved (by, for instance, increasing the slope) friction can be overcome. (Again, obvious by intuition, but I wanted to check it).
(Or, indeed, by adding mass behind the fruitbox or wallet)
stevengoddard says:
June 30, 2010 at 8:57 pm
The thread trolls will do absolutely anything to change the subject and avoid discussing the fact that East Antarctica is too cold to melt.
I couldn’t care less if some prof thinks glass flows more slowly than some other prof does. The point is that it is a highly viscous liquid, like ice.
___________________________________________________________
No, glass is NOT a highly viscous liquid at STP.
You are the one who does not understand that basic FACT!
Urban legends indeed!
For the record WUWT is NOT a SCIENCE blog.
And that’s a FACT!
“I will give a little help with the fluid flow problem.”
The only help you could give is to provide some evidence for your claims. Do not pretend to lecture me.
I happen to be a Research Hydraulic Engineer.
With three degrees with the word SCIENCE in them.
Steven Goddard understands viscosity?
I think NOT!
“I couldn’t care less if some prof thinks glass flows more slowly than some other prof does. The point is that it is a highly viscous liquid, like ice.”
You should care what actual measurements on glass indicate. Real measurements on window glass indicate that they do not flow over the time scale of centuries.
You seem to prefer the urban myth.
It isn’t a question of one professors opinion over another. It is a question of evidence.
There is no evidence for your claim that “In Europe you can see windows which have flowed downwards over hundreds of years.”
If you are going to pretend to lecture other people on your “solid understanding of material behaviour” then you should at least try to get it right.
Today, June 30, 2010, 2 hours ago | EFS_Junior
stevengoddard says:
June 30, 2010 at 6:53 pm
Chris Noble
Your grain silo analogy is incorrect for quite a few reasons. The glacial sheet is 700 km wide by 3 km high. It is like a sheet of thin glass residing on a gentle slope. In Europe you can see windows which have flowed downwards over hundreds of years.
_____________________________________________________________
Your analogy with old window glass is incorrect.
Old glass is not what is called today as float glass.
The old glass was never flat to begin with due to the older less accurate glass making processes.
Glass exhibits no viscoelastic properties at STP.
http://en.wikipedia.org/wiki/Float_glass
I can see you have all your faith in Wikipedia information.
However, Wikipedia left out an important point, glass smiths 400 years ago had strick instructions by the glass guilds to always place the thickest glass at the bottom of the window pane when installing one. You might ask Wikipedia to correct their records. 🙂
“The only thing bogus here is people who are not bright enough to recognize that ice is not melting at -30C.”
Which is a perfect example of a straw man because nobody is arguing that it does.
Glaciers do flow and they do accelerate.
“I have done this calculation for you several times.”
No. The calculation you have done is for how long it takes ice to travel 700 km if its average speed is 100 m per year. This is not the same time that it takes for an increase in the flow rate to propagate up the glacier.
Chris Noble,
Fluid flow is driven by pressure gradients (differences.) Suppose you solve the problem numerically. Let’s say you have a ten metre length of fluid in non-turbulent flow. Break it down into one foot sections.
At steady state, the velocity is constant. (say 1m/sec) Now decrease the downstream pressure slightly. That will cause the speed over the last metre to increase slightly. After almost one second, the fluid at the nine metre mark has moved to the ten metre mark, and the drop in pressure has propagated backwards to the nine metre mark. After almost two seconds, it will propagate back to the eight metre mark, and after almost ten seconds it will propagate back to the other end.
So the time required to adjust to the new pressure gradient is going to be slightly less that the time required for the fluid to travel ten metres under the old pressure regime. If we lowered the pressure at the downstream end by 10%, then the time to propagate the new pressure gradient upstream can be estimated as 90% of the old flow time.
Regardless, it is too cold to melt in East Antarctica and satellite studies show that ice is increasing.
http://www.nature.com/news/2005/050516/full/news050516-10.html
[snip -Steve, no more comments like this – A]
Chris Noble,
You are claiming that the ice at -30C in the interior of the East Antarctic ice sheet has increased velocity due ice loss along the coast. Now draw out your imaginary pressure gradient that it is causing it to accelerate to the coast, and present even one shred of evidence that the ice speed has increased out of that region.
However, the grain silo analogy is still bogus…
And 24 km^3 is trivial.
wayne says:
June 30, 2010 at 9:53 pm
Today, June 30, 2010, 2 hours ago | EFS_Junior
stevengoddard says:
June 30, 2010 at 6:53 pm
Chris Noble
Your grain silo analogy is incorrect for quite a few reasons. The glacial sheet is 700 km wide by 3 km high. It is like a sheet of thin glass residing on a gentle slope. In Europe you can see windows which have flowed downwards over hundreds of years.
_____________________________________________________________
Your analogy with old window glass is incorrect.
Old glass is not what is called today as float glass.
The old glass was never flat to begin with due to the older less accurate glass making processes.
Glass exhibits no viscoelastic properties at STP.
http://en.wikipedia.org/wiki/Float_glass
I can see you have all your faith in Wikipedia information.
However, Wikipedia left out an important point, glass smiths 400 years ago had strick instructions by the glass guilds to always place the thickest glass at the bottom of the window pane when installing one. You might ask Wikipedia to correct their records. 🙂
____________________________________________________________
I posted another link that states exactly what you have stated with respect to glass orientation.
The float glass link discusses current and past glass PROCESSING methodologies.
Some here place more weight on urban legends, that they do the actual science/engineering.
mi^3, still trivial.
“Assume for a minute that we accept the GRACE numbers. The first problem is Antarctica contains a lot of ice : 30 × 10^6 km³. At 100 km³ per year, it will take 300,000 years to melt.”
OK, several genius’ have established that it’s not melting. Most likely, if this measurement is valid, it’s the result of cyclical changes in accumulation and flow. So, it’ll probably take >> for it to all slide off as the rate would fall as the mass falls. Plus, a heck of a lot of it would have to flow uphill to escape basins and mountain ranges, etc. Nothing to lose sleep over. Al Gore can go back to trying to find somebody who’ll let him grope.
Chris Noble
It doesn’t make any difference to the discussion what the timescale of glass flowing is. If you heat it up a little, it flows faster – just like ice. My comparison was a qualitative one.
http://www.nature.com/news/2005/050516/full/news050516-10.html
Isn’t it interesting that the gigantic glacier which holds 90% of the world’s freshwater is increasing in size. Did the IPCC forget to mention that?
Steve, you keep writing that the ice is too cold to melt at -30C and no one here is arguing that there is surface melting happening. Don’t know why you continue to say there is no mass loss because the temperatures are too cold to melt, no one is arguing with you about that so why continue to try to distract with such statements?
You either seem to not understand that mass loss can happen in many other ways besides melt or you are simply trying to be political. Your entire premise of this article was wrong and purposefully misleading, and a lot of folks have taken their time to point you to references that illustrate the errors in your reasoning. I’m sorry but Chris, Robert and others make a lot more sense than you do.
stevengoddard says:
June 30, 2010 at 10:09 pm
Chris Noble,
Fluid flow is driven by pressure gradients (differences.) Suppose you solve the problem numerically. Let’s say you have a ten metre length of fluid in non-turbulent flow. Break it down into one foot sections.
At steady state, the velocity is constant. (say 1m/sec) Now decrease the downstream pressure slightly. That will cause the speed over the last metre to increase slightly. After almost one second, the fluid at the nine metre mark has moved to the ten metre mark, and the drop in pressure has propagated backwards to the nine metre mark. After almost two seconds, it will propagate back to the eight metre mark, and after almost ten seconds it will propagate back to the other end.
So the time required to adjust to the new pressure gradient is going to be slightly less that the time required for the fluid to travel ten metres under the old pressure regime. If we lowered the pressure at the downstream end by 10%, then the time to propagate the new pressure gradient upstream can be estimated as 90% of the old flow time.
Regardless, it is too cold to melt in East Antarctica and satellite studies show that ice is increasing.
http://www.nature.com/news/2005/050516/full/news050516-10.html
[snip]
_____________________________________________________________
Demonstrating, once again, a total lack of understanding of fluid dynamics, fluid mechanice, and hydrodynamics.
Supercritical or subcritical flow? Pick one.
Closed conduit or open channel flow? Pick one.
I’ll go with closed conduit.
Water Hammer;
http://en.wikipedia.org/wiki/Water_hammer
Did I mention that ONE of my areas of expertise is wave mechanics.
“Regardless, it is too cold to melt in East Antarctica and satellite studies show that ice is increasing.”
Again who says that ice loss in Antarctic is determined by melting? Who? Why do you keep on rehashing this straw man.
PS. Satellite measurements show glacier acceleration and thinning despite your protestations that this is impossible.
http://www.nasa.gov/pdf/121653main_ScambosetalGRLPeninsulaAccel.pdf
Reality does not care what you believe.
Steve, you forgot some other quotes from the study you link to:
In contrast, smaller West Antarctica showed an overall thinning of 0.9 centimetres per year. “It’s amazing that they can measure such small changes,” says Vaughan.
Thick skin
The thickening of the eastern ice sheet should not be seen as a long-term protection against a rise in sea level, warns Vaughan. Glaciers in West Antarctica are accelerating, releasing more and more icebergs into the sea. And the Antarctic Peninsula, which stretches towards South America, now regularly hits temperatures above 0 °C in the summer, leading to direct melting of the ice there.
What’s more, snowfall over East Antarctica will not continue to increase indefinitely in a warming world, Vaughan adds. Conversely, every extra degree of temperature rise will continue to accelerate glaciers and cause more melting on the western side of Antarctica, swelling the world’s oceans further.
Oh and the link of Steve’s also states:
But the panel also expected that climate change would trigger an increase in snowfall over the Antarctic continent, as increased evaporation from the oceans puts more moisture into the air.
The panel being the IPCC panel, so yes Steve, scientists were aware that an increase in snowfall over Antarctica was likely to happen. Geez…why do you constantly, purposefully mis-represent everything?!?
Robert,
you say:
Funny how you choose to ignore the actual basis of the articles and just read the abstracts.
Abstracts are all that are available to us , many retired researchers far away from libraries. It is courteous in net discussions to give links to .pdf’s . Often rogue .pdfs exist on the net of the stuff behind pay walls.
So one is left with your quotes and a lot of imagination.
I will wait for a link that can explain to me, why, when the global geoids show effects as large as the ones seen over antarctica, the explanation for antarctica has to be “ice is thinning” rather than “ice plus ground are moving”. Which brings me to the point that we do not know what ice is doing (except by watching pictures of towers being buried).
To get an answer for antarctica one would have to sound the ground and get an accurate to mm outline of the ground concurrent in time with the measuring of gravity changes, in my physicist’s opinion. Has this been done? in the one paper I have seen, Velicogna,
http://thingsbreak.files.wordpress.com/2009/10/increasing-rates-of-ice-mass-loss-from-the-greenland-and-antarctic-ice-sheets-revealed-by-grace.pdf
no. The problem seems to me is under the rug, err the ice.
“It doesn’t make any difference to the discussion what the timescale of glass flowing is. If you heat it up a little, it flows faster – just like ice. My comparison was a qualitative one.”
If you can’t admit to being wrong about an urban myth then there is very little hope of convincing you of anything.
Your “solid understanding of material behaviour” told you that “In Europe you can see windows which have flowed downwards over hundreds of years.”
Is there anything any expert can say that won’t result in insults and accusation of lies from “Steven Goddard”?
I have seen no evidence of anything else.
“Steven Goddard” – you are obviously a victim of the D-K effect. I will leave you to wallow in your own ignorance, and you can (and no doubt will) insult me at your leisure – but you will be talking to empty air, I’m afraid. You are clearly not amenable to reason, so I won’t waste my time here.
@ EFS-Junior
“Conclusion
There is no clear answer to the question “Is glass solid or liquid?”. In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid, or simply that glass is another state of matter that is neither liquid nor solid. The difference is semantic. In terms of its material properties we can do little better. There is no clear definition of the distinction between solids and highly viscous liquids. All such phases or states of matter are idealisations of real material properties. Nevertheless, from a more common sense point of view, glass should be considered a solid since it is rigid according to everyday experience. The use of the term “supercooled liquid” to describe glass still persists, but is considered by many to be an unfortunate misnomer that should be avoided. In any case, claims that glass panes in old windows have deformed due to glass flow have never been substantiated. Examples of Roman glassware and calculations based on measurements of glass visco-properties indicate that these claims cannot be true. The observed features are more easily explained as a result of the imperfect methods used to make glass window panes before the float glass process was invented.”
This is from the link you provided. I’m puzzled that you think it is a convincing final word that supports your contention.
It’s also curious that there’s a general recognition that the bottoms of ancient panes are thicker than the tops and a concomitant willingness to believe that medieval glaziers had the perspicacity to ensure that the end that was half a millimetre thicker went down.
Furthermore, it is thought these feudal artisans oriented the glass in this way because it ensured a tighter seal in the lead cames.
Do we think the leakage through the inversely mounted panes was so apparent that this practice became the approved technique, or was it just an urban myth of the 14th. century? Or maybe it is the more recent product of febrile imaginations looking to offer an explanation for every little detail of a story they’ve written for themselves.
Are you really certain that glass doesn’t sag over the centuries? How about on a mid-summer’s day with the sun shining brightly on the window? What would it take for it to soften just a little and have some saint’s jaw droop just a bit? You have to admit some of those characters look a touch lugubrious.
Ice, of course, unlike glass, flows like honey. At very shallow angles. Flows, not slides. As soon as you remove the chocks. It’s not clear to me what the force was that was holding those chocks in place. Apparently it was greater than the tremendous pressure exerted by 500 km of flowing terrestrial ice.
David
Here is clever idea. How about staying on topic and not spewing ad homs at the author?
I wonder if Steven Goddard read the actual paper rather than just the news report.
The measurements have a spatial resolution of a few hundred kilometers. Indeed the data is passed through a 300km Gaussian filter.
His claim that “GRACE shows ice loss more than 700 km from the coast.” is not supported by the paper.
jeff brown
This article is about East Antarctica, where most of the world’s ice is located.
EFS_Small
Your response was your standard ad hom with zero substance.
The dissonance level on this thread has gone off scale. I’m done here.
It is very cold in East Antarctica. Satellite studies show ice gain. The GRACE data is suspect. Even the suspect GRACE data shows 300,000 years to melt. You trolls have not a leg to stand on, yet argue about every hair-brained idea which pops into your heads.
jeff brown
Sorry one more thing. You argued all day that ice was decreasing, and finish by saying that you and the IPCC expected ice to increase, as it has.
Un-believable. Where did you intellect vandals come from?
It might be useful if Steven looked up the meaning of ad hominem.
“This article is about East Antarctica, where most of the world’s ice is located.”
The scientific papers that you are attempting to refute are about the Antarctic as a whole.
Penal colony in New Zealand, Brad? I think it is you who need a reminder of the history. Still, this seems an appropriate thread for a comment like that.
Robert, sf this one line from Steves post is correct?
“At 100 km³ per year, it will take 300,000 years to melt.”
I only ask as it just makes me wonder why any sane person would be doing the work you do in the intense cold. It also makes me wonder, taking into account the size of Antarctica, the extremely short time so few scientists have studied the place, how you can be so single minded over your (and others) theories.
I, also, find the tone of your posts to be rude. Not something I am used to on WUWT and I have watched many others come on site with a counterpoint argument.
It seems a shame because you obviously know the area well.
Geophysical forward models involving gravimetry such as the data provided by GRACE always have an inherent ambiguity in their solution. For example, ongoing elevation of the dense land surface under the Antarctic land ice will generate an increase in amplitude and decrease in the wavelength of the gravitational potential field signal. An equivalent response could well be generated by land ice loss i.e. ice thinning. Consequently, we have to be very cautious is using GRACE data to conclude that the only cause of the annual change in the gravitational potential field over Antarctica is caused by ice loss. Note, though, I have not done any modelling here, so these statements here as they apply to GRACE data over Antarctica are assertions that require qualification; but we must be very aware that interpretation of gravitational potential field data provided by GRACE to infer ice loss is only one possible solution; it is not the only possible solution.
Everybody should calm down, no meaningful discussion can be head if people take on an aggressive and arrogant tone and call into question the expertise of others. People should be judged on their statements alone, and even then, without insulting them, even if they are claiming the Earth is flat.
As a non-expert, and as the person who first brought up GRACE is a previous thread, I would like this discussion to continue in order to understand whether GRACE measured accelerating loss of ice in the East Antarctica ice sheet is accurate. It seems to me we are all in agreement that West Antarctica is losing ice.
The point of contention seems to be: can calving at the coast bring about mass reductions far inland in reasonalby short timeframes?
Steve argues that is impossible.
He points out that for reductions to be happening via the flow of ice, they would have to be visible all the way up to the coast, not only in small patches inland.
However, it is my understanding that the underground structure of the Antarctica ice sheet is extremely complex. For example, there is a vast network of subglacial liquid lakes and rivers. So much of the movement could be happening underground, where it is not visible. This is my very ignorant take on the situation, so please do correct me if I am wrong.
So point 1): does ice flow fast enough for calving at the coast to bring about melting in the interior? Are there some studies that address this directly?
It seems to me this would be the first thing glaciologists would look into. That ice is extremely viscous and cannot flow fast enough for those reductions to take place inland would be the first thing an expert would know, I’d venture. So I think it is extremely unlikely for this objection to hold value. As a non-expert, I have to rely on experts – when I am sick, I go to a doctor, I don’t search the internet to try to understand my pathology. So on this I’d say Steve is wrong. Unless there is a substantial number of ice experts that agree with him.
I’d say his point on isostasy uncertainty is far more relevant. Fortunately Cryosat 2 just went online. That should soon put to rest any speculation on what is happening to land ice. I hope that if it points to mass losses, skeptics will be ready to accept it. The opposite obviously applies to those who place their trust with GRACE measurements.
2) “Even the suspect GRACE data shows 300,000 years to melt.” I disagree. GRACE shows an acceleration in progress. 26 additional gigatonnes of ice are being lost every year. So the timeframe is shorter than 300k years.
If stained glass windows showed any sign of viscous flow, how much more the lead that holds them in place, when lead is about a billion times less viscous than glass. (See Corning Museum of Glass).
Well Robert, “gone fishing” is a good excuse for self proclaimed experts not answering any questions. The thread will be buried by the time you come back.
Ah, well, I was looking forward to learning how underlying gravity fields could be disentangled from ice changes.
I was thinking in terms of xray lazers from the satellites. There should be reflections from the solid ground that could be mapped. Even if one established the motion in time of a few mountain tops it would be enlightening.
For the non experts, this link is interesting, showing the mountain tops.:
http://lima.nasa.gov/antarctica/ .
Now how can one argue that from such a rough terrain ice from the interior drifts to the coast is a mystery . It looks kinetically trapped by the mountain ranges, to me. Maybe from unobstructed regions it can slide right into the ocean, but most paths look uphill.
Posters seem to be talking past each other a lot here. For example, they keep making arguments appropriate to different parts of Antarctica. The Grace gravitational anomaly map shows significant reductions in Lesser (West) Antarctica. Not Greater (East) Antarctica, where, within the errors, there is no overall change (some regions slightly positive, some slightly negative); so for East Antarctica, where most of the ice is, the evidence is consistent with no change, slight loss or slight gain. For the grounded ice of the Ross Ice Shelf – which is the area Robert’s arguments would apply to – there is Grace evidence of modest net loss, presumably caused by the shelf moving towards the sea somewhat faster. The big anomaly in West Antarctica seems more likely to me to be mainly tectonic – as per Anna’s crit – but may also be consistent with increased calving into the sea, glacial movement, and wind or sublimation loss from the surface.
Steve seems to be relying upon a misunderstanding of the physical mechanism by which glaciers “flow”. Ice is a solid which can very slowly creep. But forget the creep for now; glaciers would still move even if the viscosity were infinite. Imagine a solid sheet of ice, resting on a gradiant of 1 in 100, say; the surface of the sheet has a gradient of say 1 in 200 (flatter than the underlying ground); as we go further inland the ice thickness is progressively less. The ice sheet is moving downslope as a whole at 10m/yr. Assume initially that no ice is either lost from or deposited onto the ice surface. Then, to an observer stationed at any point on the ice, the thickness of the ice shows no change. But, to an observer fixed relative to the ground, the ice thickness is gradually decreasing, by 10m/yr *(1/100 – 1/200) = 5cm/yr. For the glacier to be in equilibrium, there will have to be 5cm/yr net deposition of new ice on the surface (precipitation + frost – ablation – sublimation – melt). If that deposition rate changes, the thickness, and thus gravity anomaly, at a given location will change accordingly. The thickness will also change if the velocity of the ice changes. Let the velocity increase to 20m/yr. Then the thickness will reduce by a further 5cm/yr. The velocity could increase because the pressure at the top is increased (more ice deposited or glacier lengthened) or
the pressure at the bottom is decreased (more rapid calving or penetration of water from the sea) or the ground friction is reduced (more melt water under the glacier or the ice grinding the ground smoother). Because the ice is solid, any pressure change will propagate through the entire sheet at the velocity of sound, which for ice will be a few km/s (water 1.5km/s). For practical purposes, the change propagates instantaneously through the entire glacier; the glacier moves as a block, ever far inland. Real glaciers are more complex, with sheer fractures (crevasses) and velocity gradients, but the principle’s the same; the ice thickness can be affected quite quickly by changes a long way off.
anna v says:
June 30, 2010 at 10:46 pm
To get an answer for antarctica one would have to sound the ground and get an accurate to mm outline of the ground concurrent in time with the measuring of gravity changes, in my physicist’s opinion. Has this been done? in the one paper I have seen, Velicogna,
GPS has been used for this for some time now, in Scandinavia, N America and the Antarctica, e.g. http://rses.anu.edu.au/geodynamics/gps/antarctic/index.html