Guest essay by Eric Worrall
The Australian ABC has published details of a new climate scare – the possibility that global warming will lubricate the worlds glaciers with meltwater, causing them to speed up, accelerating abrasive erosion.
According to the ABC;
Climate change may cause ‘substantial increase’ in erosion as glaciers speed up
Faster-moving glaciers carve away more of the landscape than their slower-moving counterparts, according to a new study of a New Zealand glacier.
The findings, reported in the journal Science, have significant implications for glacial erosion as Earth gets warmer due to climate change.
“The glaciers will accelerate and the rate of glacial erosion will increase substantially,” said one of the study’s authors, Dr Simon Cox of the Institute of Geological and Nuclear Survey Science in Dunedin, New Zealand.
“So we end up with more rapid carving of our landscape by glaciers and a corresponding increase in the levels of sediment and mud that are carried out in alpine streams and rivers towards the sea.”
Dr Cox and his colleagues spent five months in 2013 and 2014 studying the Franz Josef Glacier in New Zealand’s Southern Alps.
The authors found erosion to be highly sensitive to small variations in the slope of the glacier, the hardness of the rocks over which the glacier is moving, and the amount of rain the region receives.
Read more: http://www.abc.net.au/news/2015-10-09/fast-moving-glaciers-cause-more-erosion/6837954
The abstract of the study;
Assessing the impact of glaciation on Earth’s surface requires understanding glacial erosion processes. Developing erosion theories is challenging because of the complex nature of the erosion processes and the difficulty of examining the ice/bedrock interface of contemporary glaciers. We demonstrate that the glacial erosion rate is proportional to the ice-sliding velocity squared, by quantifying spatial variations in ice-sliding velocity and the erosion rate of a fast-flowing Alpine glacier. The nonlinear behavior implies a high erosion sensitivity to small variations in topographic slope and precipitation. A nonlinear rate law suggests that abrasion may dominate over other erosion processes in fast-flowing glaciers. It may also explain the wide range of observed glacial erosion rates and, in part, the impact of glaciation on mountainous landscapes during the past few million years.
Read more: http://www.sciencemag.org/content/350/6257/193
So how bad is this erosion?
… We designed this study to specifically constrain how glacial erosion relates to ice-sliding velocity. We simultaneously quantified erosion rates and sliding velocity during a 5-month period, from November 2013 to April 2014, over the entire Franz Josef Glacier, New Zealand. This glacier exhibits surface velocities that are largely dominated by high sliding velocities on the bedrock (22), up to about 3 m/day. We measured these high velocities accurately from remote sensing and expected to find large erosion rates. The analysis of continuous suspended sediment load indicated very high erosion rates (about 10 mm/year), whereas glacial sediment production remained lower than the transport capacity of the glacial system (23). We also found that the glacial sediments come predominantly from under the glacier, based on the mineralogy, fossil organic carbon, and the very low fraction of modern organic carbon found in the glacial stream (23). These observations imply that sediments collected at the glacier front can be used to constrain the glacial erosion law. …
Read more: http://www.sciencemag.org/content/350/6257/193.full
Even if erosion does accelerate, I suspect we’ll have enough time to prepare, for the consequences of erosion rates of 10mm / year, in mostly uninhabited, inhospitable regions of the world.
I expect glaciers to start advancing with Sun Cycles 25-26…
Here’s a citation to base that on:
http://digital.csic.es/bitstream/10261/107606/1/Garcia_Ruiz_et_al_Marbore_The_Holocene2014.pdf
and an article I found interesting:
http://canadafreepress.com/article/36268
This one’s great too.
http://hockeyschtick.blogspot.com/2014/05/new-paper-finds-8c-global-cooling.html
I think climate change is making me go bald !!! Can I have a couple million dollars of grant money to study this terrifying , apoctolyptic possibility ?????
less than half an inch … how is it even possible to measure that rate ?
I would think a ruler would do. Mine has millimeters even.
Good thing the Egyptians moved stones faster than that.
Just think; we could have avoided having all that Yosemite mess up in the Sierra, if those ancient natives hadn’t lit fires to keep warm. Too late to correct I suppose. Maybe there’s some Texas engineers who could fill the thing in for us ! Well maybe the Dubai Arabs could too.
So….a “high sliding velocity” “up to about 3 m/day” equates to a “high erosion rate” of a whopping 10 mm/year? I’m confused. At least they learned that “glacial sediments come predominantly from UNDER the glacier.” A real shocker there.
“””””….. The authors found erosion to be highly sensitive to small variations in the slope of the glacier, the hardness of the rocks over which the glacier is moving, and the amount of rain the region receives. …..”””””
Well hell; I could have told them that over a couple of beers for no charge.
Lemmy see; the horizontal driving force would be something like m.g.tan(theta), so steeper slopes would give bigger driving force. As for the effect of hard rocks, I would expect the ice to sink in soft soils and mud and get slowed down; but I don’t want to take too much for granite !
And as for the amount of rain; you can always depend on the amount of rain to have an effect on just about everything.
Can I bill them for some of the grant money ??
g
In terms of the “m.g.tan(theta)” thing, try thinking about how the ice sheets in the ice age moved over terrain that had 0° slope (otherwise known as flat land) for 600 miles or more – and with hillocks and hummocks, to boot.
For theta = 0°, m.g.tan(theta) = 0.
Then add in the mechanical “locking” at spurs and hills and such.
Then figure out, if YOU can, how these ice sheets went ACROSS valleys and over the other side ridge – instead of going downhill.
I can’t figure it out myself, how they can get that idea to work in the real world. It violates every principle of physics. But, I guess, since they are not physicists the realities of physics don’t apply to ice sheets. Ice flows DOWNWARD, not upward – and not over flat land without downhill (true glacial flow) flow nearby to push it (ala Agassiz’s Rhone-Jura erratic boulders).
Wait a minute. They took measurements over one 5 month period and based on that data they decided to make predictions? Even Mann tried to make it look like he had decades or more of data before mangling it to say what he had already decided the answer was.
Odd, the months were Nov-2013 to April 2014, isn’t that summer in New Zealand? Shouldn’t the Glacier be retreating then?
Yes I am confused.
michael
In the summer, glaciers generally move faster even if receding. The glaciers I knew as a kid seemed to stop moving entirely in the Winter. We used to camp right next to the Hayden glacier (on the flank of Middle Sister over Bend, OR.) It made quite an eerie racket when you were trying to sleep.
Mike, it was too cold and snowy to access the glacier during the winter. 😉
Summer in NZ is beautiful.
Magnificent place, and I say this as an Aussie,so no hometown bias.
Even better if you can go there under the pretense of “research” paid for by someone else.
This is, by far, the most alarming news yet in all this climate change stuff. Why don’t they do something about it?
Dahlquist,
Yes, we need to do something! It’s all spinning out of control! Even Arctic ice is completely disappearing, just like they predicted.
Oh, wait…
Well I visited Franz Josef glacier on New Years day 2007 and it was going downhill by having bits break off the top edge and tumble down the face of the glacier, and bounce a long way down the terminal stream. Some idiots were walking up the stream to examine these Volkswagen sized chunks of ice; and it seems that it never crossed their mind, just how these ice boulders got to where they lay.
I went up there, and a good way up the flank of the glacial canyon, but I couldn’t see any of it scraping the rock wall of the canyon, as it slip slided down at accelerating rates.
Well the real entrants in the Darwin Awards contest, were the brainiacs, who walked right up to the glacier face, and inside one of the caves at the base of the overhanging ice wall, to have their pictures taken by someone who was going to get smashed along with the camera when the ice next came down. I don’t think you could take selfies with your telephone in 2007.
Far as I know, there is no law against the whole face calving off now and then, and pureeing any once living tissue inside the caves.
Now in the interest of full disclosure; I will admit to cosying up to the foot of a lava flow that was oozing down the slopes of Mt Ngauruhoe, circa 1958/9. But lava is like thick tar, an it doesn’t crack like ice; and it was the safest place to be because of all of the house sized chunks of magma getting fired up out of the crater and raining down all around us, when we were out in the open, so the lava cliff face shielded us from the aerial showers.
Well we couldn’t ski on Ruapehu, because of all the ash from Ngauruhoe, so why not climb the volcano.
g
trafamadore: “In the summer, glaciers generally move faster even if receding.”
You DO realize that this makes no sense whatsoever, don’t you? At least as written. Are you saying they recede faster? Or move downhill faster, even when the face of the glacier moves uphill?
tramafadore: “In the summer, glaciers generally move faster even if receding.”
You DO realize this makes no sense, as written, don’t you?
Are you saying the receding is faster up-slope? Or that even with receding the front face is still moving down-slope? If the latter, then there is no receding. If the former, then WTF are these people writing about?
Amen
…and an entire generation of Greenies are now looking out their windows in Southern California, worrying about the rapidly-advancing glaciers they now know are coming for them…
The amount of erosion exactly equals the amount of deposition. It’s a zero sum game. Big deal. zzzzzzz…
“global warming will lubricate the worlds glaciers with meltwater”.
Erosion is caused by the friction between the ice and the rock, so more erosion will require more friction. Yet this study is trying to worry us about more lubrication.
I’d say they are scraping the bottom of the barrel – except that would be too close to a bad pun.
Exactly. More lubrication WILL facilitate motion, but with more lubrication it means, normally, LESS erosion.
It comes down to a science called TRIBILOGY, the science of friction. I will bet they’ve never even HEARD of it.
“the possibility that global warming will lubricate the worlds glaciers with meltwater, causing them to speed up, accelerating abrasive erosion. ”
Huh!
Wonder what non-existent warming they might be deluding themselves about this time?
How can a supposedly scientific paper refer to things for which there is little or no ongoing evidence, and use those references as a basis for the entire thrust of the paper?
But doesn’t friction cause warming? So therefore, more friction equals more warming=increased motion which makes more——-this is just so confusing.
I am putting my house on wheels just in case
Add pontoons to lower beneath the wheels if you need to.
How can retreating glaciers be advancing faster?
The same way that colder winters are caused by global warming. ☺
A glacier simultaneously receding and advancing can be explained by Quantum Theory. All you have to do is extrapolate from cat dimensions to Schroedinger’s Glacier.
\sarc if you can pry it out of my keyboard
Exactly! Journalists have fooled for many years into thinking an advancing glacier is a melting one.
Any who want to see a retreating (melting’ glacier should visit the Roseg valley in Switzerland. The locals have been putting in date pegs every 10 years for a century showing the position of the snout as it retreats towards the bulk of the glacier. Have a drink at the Boval Hutte, high up, with the massive great basin of ice to look at and it is obvious for this to melt must take many centuries.
I think you’re confusing terminology; moving faster doesn’t mean advancing.
If the snout of a glacier retreats it means that ice is falling off the end and melting or floating away faster than it is being replenished from up-hill.
Advance is the opposite.
Any glacier is always either retreating or advancing. Meares and Columbia originate in the same ice-field and are only a few miles apart; one is advancing, one is retreating.
Right, but these folks are out to make a new science that has it’s own terminology and rules. Kind of like an old Irwin Allen Sci-Fi TV series.
“How can retreating glaciers be advancing faster?”
Think of snow on top of a low sloped, metal roofed house, it’s a similar concept. The snow may initially only melt from the top and at the front edge (due to solar load and ambient air temp). However, if the metal roof temperature warms a bit, that can create a layer of melted water, which will reduce the friction between the snow and the roof, and cause the snow to slide off the roof.
From Oct 1, the same story here. Glaciers and erosion.
Climate change moves mountains — literally
Climate change is causing more than just warmer oceans and erratic weather. According to scientists, it also has the capacity to alter the shape of the planet.
http://news.ubc.ca/2015/10/01/climate-change-moves-mountains-literally/
Observed latitudinal variations in erosion as a function of glacier dynamics
http://www.nature.com/nature/journal/v526/n7571/full/nature15385.html
Climate change moves mountains — literally …
and they’ve only just discovered this? Nothing ever changed on earth until the warmish discovered climate change?
But, what about the children?
So the glaciers are going to scrape off more rock?
I think they haven’t thought through their scare tactics.
Much of that newly exposed rock is going to undergo weathering, which removes carbon dioxide from the air.
Imagine how cold the sea is going to get with all that ice crashing into it . .damn . . cooling seas . . . arctic ice increased . . Thermohaline circulation slowed and chilling the oceans . . CO2 sucked into colder seas . . . Aw Naw . . enough cooling to chill the sun . . .
Yup, Glo.Bull warming is going to cause the next ice age !!!!
Yes it will. Well, technically we’re in an Ice Age, have been for the last 2.6 million years.The warming will result in the next glaciation phase.
“…technically we’re in an Ice Age, have been for the last 2.6 million years.”
I’ve heard that before. IF true, when are we NOT in an ice age? interglacial period?
So if you’ve left anything of value under a glacier, be aware that it’s going to be more eroded when you get it back.
And we thought watching paint dry was fun.
OMG…at this rate , in a trillion years the glaciers will have eroded the entire planet out of existence ….we are DOOOOOOOMED !!!!
Well, this geologist finds it colossally tiresome when the climate kooks decide to muscle in on our territory. Ahhhhhh Shaddddappp. Is all I have to say. Glaciers Gallop. Get over it. And it’s usually because of a mass imbalance upstream.
Does CO2 cause the imbalance upstream? There could be a grant in this.
Increased glacial velocity can produce increased erosion rates but glacial abrasion is not simply a function of glacier velocity. Among the factors that affect rates of glacial abrasion are:
1. The concentration of rock debris held in the basal ice. Clean ice is not hard enough to abrade rock. Thus, the greater the content of rock debris to act as cutting tools, the more effective the abrasion.
2. A continuing supply of new rock debris brought to the ice bedrock interface by basal melting. The cutting tools of the glacier (that is, the rock fragments embedded in the ice) become worn down by the abrasion, so a fresh supply facilitates active abrasion. Without replenishment of rock debris in the basal ice, abrasion becomes less and less effective.
3. Difference in hardness of bedrock relative to the rock fragments in the ice. For example, quartz and feldspar fragments (hardness 6 to 7) will quickly abrade limestone bedrock (hardness 3), but limestone fragments will not easily affect granite bedrock.
4. Basal meltwater to remove the “worn out” grinding tools of a glacier.
5. The velocity of basal sliding of the glacier over its bed. The faster the velocity, the greater the number of rock fragments that will be dragged over a given surface per unit time.
6. The thickness of the ice. The thicker the ice, the greater the pressure of particles on the underlying surface and the more effective the abrasion as particles are dragged across a rock surface
7. Basal meltwater under high hydrostatic pressure reduces effective normal pressure. The reduced pressure has the effect of buoying up the glacier and because of the decreased normal pressure, basal abrasion rates are reduced.
8. Characteristics of rock fragments in the basal ice. Larger fragments exert more pressure on subglacial surface than smaller ones, and angular particles are more effective in abrading the surface.
9. Measurements of basal erosion rates from plates bolted to bedrock beneath glaciers suggest erosional rates of 1-10 mm/yr
The idea that increased glacial melting will result in increased glacial erosion is highly questionable because melting reduces ice thickness which reduces flow velocity and eventually the ice will stagnate. If you look at the lower part of a retreating glacier you’ll generally see much less velocity and basal erosion than in a strongly advancing glacier. Bad idea!
I was going to say earlier when I first saw this: Where’s Don Easterbrook when you need him? Thanks Don…
So basically glaciers are akin to thousands of skillsaws, with self-replacing teeth, cutting through the landscape? In any case how does any of this doom civilization which has only existed for 0.02% of human existence?
actually more akin to using wet/dry sand paper
Thanks for this summary. Really helpful.
Don: “1. The concentration of rock debris held in the basal ice. Clean ice is not hard enough to abrade rock.”
While true as a general principle, this is not strictly true, not at all. It is not just a matter of hardness.
Even softer materials will actually abrade harder materials. I know this from experience with automation. Our tracks and guide would be made of tool steels hardened to 60 Rockwell C, and yet this steel would – over time – be worn down by plastic parts that weighed less than 25 grams (sometimes less than 5 grams). The track and guides would have to be replaced periodically. This is 100% real world stuff: Softer materials CAN AND DO wear down harder materials.
You can argue it all you want to, but in the real world of industry this is what happens. Those 60 Rockwell C tracks don’t last forever.
New?
Paper from 1969:
http://www.nrcresearchpress.com/doi/abs/10.1139/e69-097?journalCode=cjes#.Vhlgnv_ov4g
Climate scientists don’t need to research earlier papers. To them it is ll new, all AGW/CC.
I live in Colorado at about 6,700 feet above sea level. Should I be concerned about sea-level rise?
Yes. The glaciers moving faster will erode the mountains quicker thereby getting you to sea level sooner. Coupled with the rising water from the glacier melt you could be in trouble tomorrow.
Around 3.41 PM,… with 97% certainty according to my model
She models Wellington boots !!!
No!
Scientists in Colorado have found global warming will hit “two days before the day after tomorrow.”
I saw that on tv…I think it was in the news.
Only costal cities will feel the effects of sea level rise and given the current rates of fluctuation, we’ve got 20,000 years to adapt. So no, you’ve got nothing to worry about even if all the ice on the world melted tomorrow. If anything, I would keep an eye on Yellowstone…but don’t lose sleep over it. Lol
Well, this is something I know about, having lived and climbed in the Swiss Alps for many years. When the climate warms priecipiration falls more as rain than snow, weight stops accumulating at the head of the glacier and it basically stops moving and instead melts from the tongue. conversely, during the little ice age the Alpine glaciers grew very rapidly and extended into the valley floors. The ones under Mt Blanc came into the valley at Chamomix and ploughed up the apple orchards. They asked the bishop to come up from Geneva and try to make it stop.
I’d these idiot alarmists would just read some history they could find this out for free.
Those alpine glaciers contribute a beautiful blue colloidal suspension of minerals to the lakes.
More melt water, greater speed, less friction. What am I not understanding about glacial erosion?
The melting of the bottom of glaciers and ice sheets from the volcanic activity beneath them will be hard to stop.
But the glaciers are all retreating, don’t you read the IPCC reports.
Just guessing but I doubt the New Zealand tax payers who helped fund the study received no lubrication…
Funny . I always thought the glaciers advanced forward because of the added weight of accumulated snowfall !!!
Got to overcome friction
What’s wrong with more erosion? Mechanical erosion from a glacier means more rock is ground down to finer and finer particles which allows chemical weathering to break down the elements in the rock which makes them more available for uptake by plant life. This is not a problem, this is very good! Seems to me that some journalist is trying to exaggerate a normal process and make it seems like a horrible effect of CAGW.
They wouldn’t do that…would they ?? LOL….
Nov-2013 to April 2014 is summer in New Zealand. That would help. ‘Expect’ and ‘imply’ are key words in this paper. They are probably also expecting increased grants and funding from this work.
The valley in which the glacier under discussion is situated is located on a Plate Tectonic Boundary. The whole area (Southern Alps near Mt Cook) is being uplifted at 5 to 10 mm/yr. So basal erosion is roughly equivalent to uplift and the bedrock altitude is probably close to a steady state.
This glacier is also subject to dramatic phases of advance and retreat which relate primarily to changes in precipitation. Advance/retreat lag precipitation by only about 3 to 5 years because the ice flow is so fast (relatively short and steep catchment). Here precipitation is strongly influenced by ENSO events. Strong El Nino events tend to be followed fairly quickly by significant ice advances.
Coming soon, SharkGlacier, another made-for-television disaster film.
You mean…YES?…that glaciers will be…YES?…less than…OMG…glacial.
And what about the invasion of snails that move at more than a snail’s pace?
OMG – Something’s going on outside…arghhh…what did that?
Our nation and our world is facing an economic and environmental crisis of disasterous proportions.
Prepare to be…startled:
Glaciers melt from below, from contact with geothermal sources, not from the air.
Where is melting most likely to occur, where the ground is 50 F 50 feet below the glacier or from the air where it’s -20 F 10 months of the year?
If they are being lubricated with water, then by definition, there will be less friction.
Less friction means less erosion not more.
Perhaps, I should disconnect the water hose from my concrete saw to make it cut better.
With sufficiently increased friction, movement will cease and so will erosion.
Rivers are notably full of water and are responsible for a lot of erosion.
Alpine glaciers are rivers with a large amount of their contents in the solid phase.
There is nothing wrong with advancing and retreating Franz Josef glacier (Or any other glacier in the NZ Southern Alps having been there to see them). But the study is complete tosh to be applied more wide spread than just a single glacier. But the ABC will have done it’s work in propagating the propaganda.
…after all, we know we have global warming from a single tree ring somewhere in Russia.
Very good. I hadn’t though of it that way.
And all men are a**holes because one woman got stood up one night in 1998. /snarc
If the glacial rates are non-linear, then from a geophysical and exploration geological perspective, ‘all bets are off’. And accelerating glacial flow actually means accelerated ice production at the glacier headwaters (or should that be headicers?).
As I understand it, most ‘permanent’ thick ice as occurs on Antarctica and Greenland is so heavy that it has depressed the land mass on which it sits, forming basins to depths well below sea level. ‘Lubricated’ ice would have to flow up hill. Besides, ice masses do not advance by physical flow over a land surface but by molecular creep.
Ahh, YOU are understanding some things here.
Flowing uphill was invented by Louis Agassiz to explain the erratic boulders on top of the Jura Mountains in western Switzerland. The Rhone Glacier valley T’s into the wide valley to the SE of the Juras, and Agassiz explains the erratic boulders by having the Rhone glacier flow all the way across the wide valley and push boulders UP the far side – the SE slope of the Juras.
While this unique geography might – MIGHT – correctly explain those particular erratic boulders, geologists and glaciologists have extrapolated Agassiz’s Jura special situation to declare that ice can flow uphill everywhere – and even when there is no glacial “push” possible.
Also, yes, it is plastic flow within glaciers by which they flow. The interface with the underlying ground is actually where the plastic flow is least. The top surface of glaciers flows fastest. This is why crevasses form – the top surface flows faster than the next lower layer upon which it rests – stretching the near-surface ice until it cracks. The term “layer” here I use loosely, since plastic flow is a laminar flow and there are THOUSANDS of such shear layers within the ice.
Also, YES, the interior ice sheet in Greenland is in a basin. And there are very few outlets to the coast, for that ice sheet.
Thus, there are two entirely different zones of ice in Greenland – 1.) the interior ice sheet, and 2.) the coastal slopes. So, when discussing Greenland ice, it is necessary to spell out which ice is being discussed. The coastal zone is glaciers. The interior is a contained ice sheet, contained by a ring of mountains. The ice in the two zones act differently because of the effect the terrain has on how the ice can flow (or not).
The Franz Josef Glacier is on the Wets Coast of the
South Island of NZ. That is not a mis-spelling. It’s the
name we locals give the southern part of the West Coast
from about Hokitika (average rainfall about 10 inches
per month) south. The precipitation there sometimes
has to to be seen to be believed.
The Southern Alps are fold mountains pushed up by
the collision between the Pacific Plate and the Australian
Plate. The Australian Plate there is overriding the Pacific
Plate. The main fault line runs down those mountains
some hundred kikometers plus or minus a few inland
from the West Coast. Of course there are also hotpools
near the glacier as advertised in this
tourist brochure.
To advance at 3m per day would require massive annual
snowfalls on its source snowfield which is only about
20sqkms in size. If it ran at that speed without feed pressure
behind it, it would melt pretty quickly
The last time it advanced started in 1984 and it’s been
known to advance at up to 70cm per day. But don’t worry,
you can still out walk it even at 3m per day. It’s been in
retreat again over more recent years.
There’s nothing there for it to threaten except some klimate
“scientist’s” sense of impending disaster.
The process involved is called regelation. A pressure of at least 20 tons per sq. inch is required.Ice immediately melts at that pressure, as the bottom of the glacier contacts the bedrock. on release of the pressure the ice immediately refreezes. The glacier is effectively sliding on a thin film of water. ice skaters
are using the same principle. Melt water from whatever cause will have no effect, except to maybe wash away wornout fine particles of rock, because meltwater cannot access the pressurized joint between the
glacial ice and the bedrock. Scepticism is Good.
Ken, I think you make a point that is just ignored by many, in the calamity over moullins, and other surface melt phenomena.
In order to have liquid water between the ice and the rock, that water layer has to have an internal pressure that is equal to the pressure of the ice that it is supporting.
Actually the water internal pressure would have to exceed the ice pressure because of the effect of surface tension. Well I suppose that would depend on the boundary layer at the water ice interface, and the water rock interface.
The surface melt water running down cracks in the ice to the rock face, is going to have an internal pressure that is close to atmospheric, so there is no way that water can squeeze in between the ice and the rock, to float the ice on a liquid film.
Any water interface pretty much has to be a consequence of pressure melting of the bottom surface of the glacial ice.
Water likes to stay out of narrow spaces, which is why sharkskin like patterns on surfaces are used to reduce the viscous drag of boat surfaces.
A sanded boat hull has less drag, than a polished one.
3M Scientific Anglers, makes a sharkskin fly line, which floats higher and drier by having a grooved pattern which water cannot penetrate into because of the 2t/r excess internal pressure required to support surface tension contraction.
g
Good stuff, sir.
May I inquire what effect this thin film of pressure-induced water has when the bottom is seriously uneven?
And how thin?
Near the front face of the glacier there certainly is not 40,000 psi at the basal ice. Nor near the lateral edges. Complications everywhere.
All of what you say, plus perhaps these of mine, are reasons to dismiss this paper as oversimplification. As always, the devil is in the details.
“The Australian ABC has published details of a new climate scare”
Where is the scare in the ABC article?
It just looks like a straightforward piece of research to me.
Looks like garbage to me. A 5 month study of one glacier (FJ) during a New Zealand spring/summer is indicative of what exactly? Here’s a little factoid you won’t know about this glacier Harry. At some elevation, I don’t recall how far up from the valley floor, there is a lookout, good spot to take pictures of the glacier pouring over the rock face opposite, and right next to it on the ground is a small pool, with a small stream leading down the road to the valley floor. Put your hand in the pool, from memory I would say the water was a comfortable 45c. So, these “researchers” ignored possibly the primary reason glaciers all over the southern alps change and that is geological activity on a very active fault system with pools of warm water rising above the valley floor.
Patrick.
So you are saying the rate of volcanism is increasing, and this is explanation for glacial retreat. Perhaps you can publish a study?
Why point is there is nothing alarming in the study I can see. It is interesting if the researchers have a hypothesis about erosion rates. Considering global warming is causing a lot of glaciers to move faster, I can see why the Australian ABC is interested in it.
Can you point to where I say the changes are due to volcanism. Ah, thought as much…you can’t. If you can’t correctly quote anything I have said you’re not worth responding to again.
“We would like to track back in time to see how erosion has evolved over the last 12,000 years or so, since we had our last real warming up of the climate…”
Seriously? These nincompoops are comparing today’s small warmup since the LIA, which isn’t even on a par with the MWP with our coming out of the 1,000-year ice age known as the Younger Dryas?
They have the audacity to call themselves scientists?
Melting glaciers are largely the result of the end of the last ice age. Has the climate changed since then? I would suggest not.
Meh. Canada is covered in glacier till. Didn’t hurt us anyway.
Keep the insane predictions coming, believers!
So if glaciers recede, it’s proof of global warming. If glaciers advance, it’s proof of global warming. I get it now 🙂
It is utterly amazing how many times scientists will mentally simplify a process in order to get the answers they want.
If you google “plastic flow glacier movement ” like I did, you will find all sorts of DRAWINGS of glaciers moving downhill, and pretty much all of the m that show water at the base show the entire weight of the glacier floating on the VERY thin layer of water – as if the water is spread out evenly under the ice and the ice never once pushes down through that thin water layer to solid ground.
BALDERDASH!.
The water will only exist down there in relatively small locations where there are voids in the basal ice. 90-99% of the ice will be in solid contact with the ground surface. IOW almost all the ice is still touching the ground, not floating on top. The glacier ice will push down and squeeze the (more fluid) water OUT from under it and into cracks and such where the load is less. Remember that 8/9ths of icebergs are under the surface of the water at sea. The weight of the ice pushes the water aside until a weight-density equilibrium is reached. This is also true of glacial ice – 8/9ths of it will try to be below the surface of the water.
The only case in which ALL the ice floats on top is in some lab experiment where the bottom surface of the ice is flat, to match the flat bottom of the water container. And then you are talking about icebergs, not glaciers on rough, uneven slopes. (Then add in the churning of the ice, in its plastic flow…)
This oversimplification is a cartoonish idea that should be thrown out with the bathwater.
Since this is all in the erosive bottom of the glacial valley, what DIFFERENCE does it make to anything or anyone? Plants don’t seem to take hold in glacial till. Darn near every glacial moraine I’ve ever seen photos of has no vegetation it. It is all just heaps of rubble. And the valley UNDER the glacier means nothing to anyone. It’s not like there is a National Forest growing underneath the damned thing
IN ADDITION, let’s follow THAT line of reasoning…
The greens complain when glaciers recede, and they complain when glaciers advance.
What we have here is a bunch of people who will grasp at any straw to yell and scream that the world is changing and THAT IT IS ALL MAN’S FAULT. They hate humans, period. WHO THE HECK CARES WHAT THEY THINK?
I was once an ABC fan and friend of the ABC. No longer. The ABC has has lost all credibility on both scientific and political fronts. It is becoming an irrelevance.