From SWANSEA UNIVERSITY and the “if ice cracked in the Antarctic before airplanes and satellites existed, did it make a visual?” department.
New branch revealed in latest data from ice shelf
The rift in the Larsen C ice shelf in Antarctica now has a second branch, which is moving in the direction of the ice front, Swansea University researchers revealed after studying the latest satellite data.
The main rift in Larsen C, which is likely to lead to one of the largest icebergs ever recorded, is currently 180 km long. The new branch of the rift is 15 km long.
Last year, researchers from the UK’s Project Midas, led by Swansea University, reported that the rift was growing fast. Now, just 20km of ice is keeping the 5,000 sq km piece from floating away.
Professor Adrian Luckman of Swansea University College of Science, head of Project Midas, described the latest findings:
“While the previous rift tip has not advanced, a new branch of the rift has been initiated. This is approximately 10km behind the previous tip, heading towards the ice-front.
This is the first significant change to the rift since February of this year. Although the rift length has been static for several months, it has been steadily widening, at rates in excess of a metre per day.
It is currently winter in Antarctica, therefore direct visual observations are rare and low resolution. Our observations of the rift are based on synthetic aperture radar (SAR) interferometry from ESA’s Sentinel-1 satellites. Satellite radar interferometry allows a very precise monitoring of the rift development”.
Researchers say the loss of a piece a quarter of the size of Wales will leave the whole shelf vulnerable to future break-up. Larsen C is approximately 350m thick and floats on the seas at the edge of West Antarctica, holding back the flow of glaciers that feed into it.
Professor Luckman said:
“When it calves, the Larsen C Ice Shelf will lose more than 10% of its area to leave the ice front at its most retreated position ever recorded; this event will fundamentally change the landscape of the Antarctic Peninsula.
We have previously shown that the new configuration will be less stable than it was prior to the rift, and that Larsen C may eventually follow the example of its neighbour Larsen B, which disintegrated in 2002 following a similar rift-induced calving event.
The MIDAS Project will continue to monitor the development of the rift and assess its ongoing impact on the ice shelf. Further updates will be available on our blog (projectmidas.org), and on our Twitter feed”
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Sea ice reaches record extent. Followed by large ice bergs being created.
Wake me when something interesting happens.
LOL….my first thought too……too much damn ice
Antarctic sea ice was running above average for years and year, until it encountered a stepwise decrease at EXACTLY the same time that the NOAA satellite went down, you know, the same time that all of the sea ice data and links went haywire. Since then it has been running below average. Talk about a coincidence.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
That is just plain wrong. Antarctica sea ice levels have been at record lows all year. As have Arctic sea ice levels.
Germinio
Nope. Yes, Antarctic sea ice area (extents) have been low during the El Nino months of 2015-2017, but the same type of dip occurred many times in the past. These recent lows are smaller than the historic record.
Since 1992, the Antarctic sea ice has been steadily rising – reaching an all-time HIGH in June 2014. The EXCESS Antarctic Sea Ice at that time was larger than the ENTIRE GREENLAND ICECAP! But you chose to ignore that inconvenient truth then. And now.
no no no I’m telling you that you are all wrong. OMG WHY WONT YOU ALL LISTEN TO ME! SSNNOORREE. Sorry all but I just could not help it. Back to our regular show. 🙂
“These recent lows are smaller than the historic record.”
.
.
“There is currently less sea ice surrounding the Antarctic continent than at any point since reliable records began in 1979.”
.
http://www.cnn.com/2017/02/16/world/antarctica-sea-ice-record-low/
Time to plant splodie chargies from the rift to the coast along several paths and blow this berg outada wadda
At least break it into smaller more manageable sizes
That’s odd.
MASIE has 2017 extent above 2006, 2007, 2009, 2011, 2015, and 2016.
Gernomio.. take a jump !!!
Current Antarctic level is above 1980 level , and catching up the decadal minimum
Hahahahahahahahahahahaha!!!!!!! That joke just never gets stale. Tell it again!
Plain wrong? ha ha ha ha ha. You should go down there immediately and hold the two pieces together. Hold on tight. And dress warm, winter is just starting.. Someone might eventually bring you some food and hot cocoa.
They are comparing the possible big-berg to Wales, which has an area of 8,016 square miles. However back when I was a kid, in 1816-1817, an area if ice estimated to be 18,000 square miles came south into the North Atlantic.
?w=584
I wrote a post about the discharge of ice from the north, and how it might have caused “The Year With No Summer.” It had nothing to do with CO2 and definitely didn’t warm anyone.
(The post is a bit rambling, so you might want to skip down a bit.)
https://sunriseswansong.wordpress.com/2017/04/28/arctic-sea-ice-fram-jam-philosophy/
Geronimo’s “this is just plain wrong” quote cranked up my humor juice and I wrote a couple of posts over at Jo Nova’s blog, touching on topics of giant heads, oversized sanctimony glands, famous mash-ups, and mainly warning our friends down under of the impending calamity that COULD be caused by the big iceberg calving event. I warned them about the berg crashing into Australia or even Melbourne with enough force to tip over the continent, like happened to Guam a few years back (those poor people).
Now I have an even BETTER idea. A new disaster movie called “Frozen Tsunami” which will put “The Day After Tomorrow” and “Sharknado” to shame (okay, now understand that NOTHING puts Sharknado to shame, it’s the best. I’m only claiming this for PR value and the monetary benefits I expect to reap from selling my good idea to a movie studio). Anyway, after the iceberg calves, the Frozen Tsunami picks up speed in the Southern Ocean currents, then suddenly a freakish winds pushes it straight toward Melbourne harbor, where it threatens millions of people. Tara Reid’s boobs will co-star with some other people as they panic and run around, while a brilliant scientist figures out a way to corral the giant iceberg like a superhero rodeo cowboy. He’s mostly successful, stopping the Frozen Tsunami after only a few thousand nude sunbathers have been squished by the berg, but he finally anchors the thing safely before it can destroy the metropolis itself (spoiler alert). The epilog at the movie’s end will show giant piping from the now safe off-shore anchored iceberg carrying tons of fresh water to irrigate the Australian desert, and to wet down Tara Reid’s flimsy t-shirt with very cold water, if you get my meaning..
I think it’s a slam dunk blockbuster, what do you think?
To read my JoNova posts, click here:
http://joannenova.com.au/2017/05/abc-pushing-suppressed-scientists-story-but-misses-that-csiro-wont-even-employ-a-skeptic/#comment-1910334
You missed your calling.
All I can note is that the projected iceberg is already floating, and fairly far north for Antarctica already.
Aren’t rifts caused by the freezing and expansion of ice rather than thaw??? Yea, I thought so….
Prof. David Vaughan about this topic in a Radio BBC interview some weeks ago:
“…it would be a mistake to connect this immediately with some kind of global warming. At Halley, where we have measured the temperature routinely on a daily basis for almost 50 years, we haven’t seen any evidence for climate change in that area…”
http://www.bbc.co.uk/programmes/p04p5zl2#play
http://www.kaltesonne.de/no-news-kein-klimawandel-auf-der-britischen-halley-station-in-der-antarktis/
Ooops – Sorry:
The british Halley 6 station is not near the Larsen ice shelf. So please forgive my mistake and forget it…
john May 2, 2017 at 3:51 pm
If you look at the 1st posted graphic in the article you should note that the rift started on the right-hand side of said graphic …… at the boundary edge of the “floating ice pack” and the open water …….. which infers that the rift is the result of both “upward” pressure due to the “inflowing” tidal and wave action trying to uplift the ice …… and the “downward” pressure exerted by gravity when the “outflowing” tidal and wave action recedes.
Ice will not bend or twist …….. but it will eventually fracture, thus causing a huge “rift” if sufficient pressure is applied for a sufficient amount time. Like the river ice “breakup” in the north country is a result of the inflow of the “springtime” meltwater into the river channel “uplifting” the ice and causing it to fracture.
I grow tired of this nonsense. This shelf has absolutely nothing to do with the main continental ice mass. It could go away completely and have zero effect on the stability of that mass. It’s technically a borderline Mid-Latitude feature for crying out loud.
I am also confused by some of the article (as I suspect was the intent). This is an ice shelf. It is “already” supported by sea level buoyancy. I cannot “calve” in the traditional sense like a suspended ocean front glacier. It is already floating. It is an ice berg. It merely will float away or not depending on ocean and wind currents.
It’s still connected to the rest of the glacier that’s still on land, so it can’t float away until that connection is broken. Hence the interest in the growing rift.
rocketscientist
Many areas of the “ice shelves” off of Antarctica do rest on the bottom (so their upper elevations are pushed up above the sea level more than the 10%over-90%underwater “height” rule common to fully-floating flat icebergs, but not all areas. Other “ice shelves” have areas near the coast that resting against the bottom (slide across the bottom might be a better concept), floating areas with sea water below the shelf, and then second areas further out that again rest against the shallow bottom – thus pushing up the upper ice.
“Many areas of the “ice shelves” off of Antarctica do rest on the bottom ”
Then it is emphatically not an ice shelf.
What percentage of an ice shelf has to be free floating in order for it to be an ice shelf?
Archimedes assured us this has Zero SLR implications. And new temp series for the Antarctic penninsula show it is cooling, not warming. So Larsen C crack, yes. CAGW, no.
“It is currently winter in Antarctica, therefore direct visual observations are rare and low resolution. ”
Sorry, it is only the start of May, winter is still coming. But, yes, I suppose the start of winter is still winter.
It was their excuse for not having good pictures.
Seems to me this crack has been forming for at least 7 years and perhaps more than 10 years. Nothing spectacular after all those seasonal changes of winters-springs-summers-falls, not to mention one of the biggest El Nino’s. Fear mongering as usual!
I can’t believe you deniers aren’t concerned about the poor polar bears that will be whisked away on this devastating event and suffer a terrible fate, and…what….. Oh….., Never Mind!
According to Greenpeace the real problem is that the polar bears will be forced to eat the penguins.
That’s hilarious! I suppose some might just believe it?
😉
Lord Monckton, that issue, polar bears forced to eat penguins, appears to have been solved. When I was at Seaworld in Orlando, Florida, I bought a refrigerator magnet showing a polar bear family and a penguin family happily co-existing on an iceberg. Looks like they just send out for tofu! Keep up the good work!
They will just dance with their happy feet and charm the polar bears into not eating them. Problem solved.
I assume you mean penguins, No polar bears on Antarctica
I think Lord M of B was being sarcastic.
Joe, do you really need people here to add a /sarc tag? I’m disappointed…
Oh, so you are a segregationist?!?! Polar Bears not allowed to move to the South Pole? Is it because of the color of their fur? For shame. 😉
Two point takedown to Monckton.
The penguins ate them.
Maybe the more nervous ones already migrated because of climate change. They can swim, you know.
Actually the original “Penguin” came from the Arctic but became extinct because of Climate Change (sarc).
https://en.wikipedia.org/wiki/Great_auk
Joe Bastardi – polar bears refugees !
They are there…just well camouflaged. 😉
Ah, but aren’t there some “tropical” penguin species nearby a few hundred miles away? Perhaps it is them to which LM refers!!! Sarc!
Well after all, it is the Larsen ice shelf:
http://24.media.tumblr.com/tumblr_lcxdxn1EzV1qa1ajeo1_400.jpg
:o)
Gee, can’t we ask Kimmy in NK for some of the sat data from KMS-3 or KMS-4?
Seems to be in a NS orbit and could easily observe the Antarctic…
Or maybe too busy for the EMP over the US??
https://en.wikipedia.org/wiki/Kwangmy%C5%8Fngs%C5%8Fng-4
Google Earth Timelapse of the area in question going back to 1984. Annual satellite shot over 32 years.
First, the ice-shelf is rapidly flowing outwards and has probably “increased” its area over the last 32 years. It is due to calve a big ice-shelf berg after this much growth.
Secondly, there is a small peninsula that sticks out here that disrupts the ice-shelf flow underneath and causes cracks. This latest crack is the just the first one in a long line of about 8 other cracks coming in from behind. This crack probably started more than 100 years ago.
Third, Larsen A and Larsen B just above this image appear to be rebuilding themselves. They do not have significant glaciers feeding them, so were probably always just fast sea ice build up which has now rebuilt itself since their infamous “collapse”. It was probably always just a big ridiculous exaggeration.
https://earthengine.google.com/timelapse/#v=-68.26147,-62.2395,6.841,latLng&t=2.57
Now how do you expect Professor Luckman to get funding if you go around talking like that?
Amazing. Floating ice is dynamic at both poles. Thanks for bringing rational thinking to a topic that the consensus has made so irrational.
But which state will be the same size as the ice floating away when this crack opens up and floats away to sea? Will it be Rhode Island again? Or Long Island? What? Long Island isn’t a state? And how many gazillioins of gallons of fresh water (which is less dense that sea water and will float on top of it unless there’s a mixer going on) will be available when it melts? Will it swamp the coast of um, um, um, um, oh! South Africa??? (Sorry, I’m running out of snarky panic questions that LSM reporters usually ask. Maybe someone else can come up with some.)
If this ‘berg bumped into Midway island, would it (Midway) capsize?
Significantly bigger than Maryland not quite as big as West Virginia.
Remember the Wilkins ice shelf breakup, where we lost the ice bridge between Latady and Charcot islands? Looks like it’s back.
https://earthengine.google.com/timelapse/#v=-70.28147,-74.32395,6.841,latLng&t=2.57
That is probably just sea-ice at the moment. However if it stays around for a while it may become shelf-ice. In high-precipitation areas (like this) snow can accumulate at the top and turn into ice faster than the ice melts at the bottom.
Zooming out and looking northward on this map you are able to view the collapse of the Larsen A and B shelves and the subsequent reforming over the last 5 years.
Yep. As glacial ice pushes out the “floating” ice “rifts” and becomes,,,, OH MY GAWD!!!!!! Antarctic Sea Ice. Almost like it is some sort of fucking cycle. Who woulda thunk it!
Lets tow it to Ethiopia and Yemen to help ease the drought there and send the bill to Saudi Arabia.
Cheers
Roger
http://www.thedemiseofchristchurch.com
I was thinking of hauling this massive berg to the northern Great Barrier Reef. That should keep the alarmists quiet for some time. Send the bill to Cook University or take it out of their grants.
Visited the G Barrier Reef last November off Cairns. We were told it was healthy and what we saw was fantastic.
Cheers
I wouldn’t say ‘healthy’. Healthier maybe. There is some evidence that certain coral reefs can regenerate depending on their depth and initial complexity. But they are still being ravaged by the warming ocean temperatures and pollutants.
You may have missed it, but this site had coverage within the last few weeks that some of the damage to the Great Barrier Reef was due to sea level changes associated with ENSO, and El Nino is not associated with global warming per se.
I wasn’t talking about global warming, per se. I was responding to @rogerthesurf regarding the GRE Barrier Reef being healthy. ENSO may not be driven by global warming, but global warming is disrupting it’s long lived cycle!
Berhead,
The people who have been running their tours for years in Cairns told us the reef was normal. Athough there could be some self interest there, the fact is, they would know because they go there every day. Sure there is some bleaching but it is normal for coral to die in due course. But really when you see the coral garden down there, it it is fantastic!
Far more and better than we expected.
Cheers
Roger
berhead,
The great Barrier Reef will never be healthy while there are copious funds available to study its impending demise.
they are still being ravaged by the warming ocean temperatures and pollutants.
So you claim. But tha’ts the green ‘assumptive close’.
Something is happening, ergo its down to MANN MADE CLIMATE CHANGE.
My coffee is getting cold. Arrggh. Its Mann made Climate change!
bar head is trolling. Dnftt
berhead: The reefs are so sensitive that a warming of 0.01C is enough to start killing them off?
“There is some evidence that certain coral reefs can regenerate depending on their depth and initial complexity.”
10,000 years ago the Great Barrier reef was as dead as Julius Caesar since it was at that time a low chain of limestone hills well inland. This happens at least once every glacial cycle, and often several times, and it has been going on for a couple of million years. So, yes there is some evidence that coral reefs can regenerate, for example the fact that they exist.
That was actually a sub plot in the movie ‘Brewster’s Millions’.
In the ’70’s there was a movement to tow ice bergs to Saudi Arabia because it appeared to be more competative in cost to their desalination efforts.
Nothing ever came of it though. 🙂
https://www.fastcompany.com/1755444/watch-tugboat-drag-arctic-iceberg-parched-people-half-world-away-video
Do you know why the scientists use kilometers instead of miles? Because a kilometer is 0.62 mile and the kilometer numbers are larger than the mile numbers. So 15 kilometers is 9.3 miles. Not nearly as big a and impressive as 15KM.
OMG! Wait until these watermelon climate scientists discover millimeters…
Since it’s sea ice why not use nautical miles? 1 nautical mile equals 1.852 kilometers. Thus it could be said that 15 kilometers is about 8 nautical miles or just a quick hop to the convenience store down the road.
No, no! That makes the numbers smaller! No! They want BIGGGGG numbers! Big scary numbers! Should we tell them to stop using KM and start using just meters instead? Much more panic-inducing, you know.
It should surprise me that you think the reason they use km is because it makes things sound scarier, but it doesn’t.
Wasn’t there somehalf-barmy theoryofcreating a “plastic” hollow berg, filled with ice from somewhere, so that it could be floated to drought stricken areas of the globe? I’m sure I saw it on Tomorrow’s Wolrd, unless the beers had kicked in & I’d imagined it all!
How long would it take for a really BIG iceberg to melt on it’s way to Saudi Arabia,as it crosses the equator in a ‘gobally warming” world ?Shurely shomeone can work it out .:-)
What an unmitigated disaster for the earth!! Ice sheets have never, ever calfed off Antarctica before! What will we do? How will we survive?
We’re even more doomed than we were.
This was an interesting post! I hope to go down to Antarctica this fall to study seals, and I’d rather not see a giant iceberg where this rift is right now!
berhead,
Why not, I would expect such a calving to be a spectacular natural event, and to witness it a once in a lifetime opportunity. There would still be lots of ice left for the seals.
A spectacular event, indeed. But an event that demonstrates the critical state our environment is currently in.
The environment is in the exact same shape it has always been in, flux, constant and continual change. All the alarmist crap is just that, crap. Climate changes, humans are not causing it and humans can not stop it.
A spectacular event, indeed. But an event that demonstrates the critical state our environment is currently in.
ROFLMAOAKMLITA!
You truly are a master of the assumptive close, aren’t you?
A spectacular event, indeed. But an event that demonstrates the natural feedback inherent in keeping the climate stable.
If by “demonstrate the critical state” you mean “show that nothing much is going on” you got it right.
berhead: Really? An event that has happened millions of times before indicates that things are worse than we thought?
Maybe you should spend sometime studying reality instead of penguins.
An iceberg that calves off a glacier front and splashes into the ocean is spectacular (but don’t try to wiew it from close up). A piece of shelf-ice breaking off and floating away is approximately as spectacular as watching paint dry.
Leo Smith on May 2, 2017 at 9:51 pm
A spectacular event, …………
ROFLMAOAKMLITA!
———————-
I know ROFLMAO but what is the OAKMLITA bit please, Leo.
Leo Smith on May 2, 2017 at 9:51 pm
A spectacular event, …………
ROFLMAOAKMLITA!
———————-
Sorry thst should be:
I know ROFLMAO but what is the AKMLITA bit please, Leo.
How many seals live on the top of a 350 meter thick ice shelf? Not many I’ll wager. How phony are you? Completely, I’ll wager.
One really has to wonder to what extent an ice shelf floating on sea water is capable of “holding back” glaciers that are flowing downslope under the influence of gravity. And the glaciers are being fed by snowfall on the land surface.
Instead of sea ice “holding back” glaciers, it`s more appropriate to say that glaciers are pushing the sea ice out and away from the land, where ocean currents are going to break off chunks of it. It`s a continuous process, except that chunks breaking off is intermittent rather than continuous.
The use of the words “holding back” would imply (to the less sceptical reader) that once a big chunk breaks away, then all hell will break loose, the entire Antarctic ice cap will come galloping down into the ocean and (by extension) sea levels will rise by several metres overnight. Doomsday approaches, and the end is nigh.
Merchants of Doom, that`s what these alarmists are. And it`s All Your Fault (for filling the tank of your SUV).
EXPLAIN THIS: It appears that the “glaciers” that feed the ice shelf are moving at 0.7 – 0.9 m/day. But, ~50 Km away, in the center of the shelf the ice is moving at 2.0 m/day. Doesn’t this violate the “ice shelf conservation of integrity”? How can the confined center of the shelf be moving faster than the feeding mechanisms?
Please excuse the expression, but shouldn’t there therefore be, “a lot more calfing going on out there?”
About two weeks ago I visited a temperate glacier, Fox Glacier in NZ.
There is a discussion in this part about the speed of its flow in various places and seasons.
The path to the Fox terminus
The path to the Fox terminus with the Chancellor Ridge behind.
Due to the effects of friction glaciers move fastest in the middle – relative to the valley walls – and at the top – relative to the valley bottom. As the ice flows from the broad névé into the narrow confines of the glacier convergence causes compression in the central section of the glacier. In the Fox Glacier this is also where the ice starts to flow faster as the gradient steepens.
The top 50m of a glacier is known as the fracture zone. Here the ice tends to move in one piece and subsequently is quick to crack into crevasses as gradients change and underlying bedrock features cause stress fractures.
Below 50m the pressure on the ice allows it to move with a plastic flow like a very viscous liquid.
Eroded ice and ground rock at the terminus of the Fox Glacier: summer surface melting averages 129mm a day reducing to 22mm in winter.
Eroded ice and ground rock at the terminus of the Fox Glacier: summer surface melting averages 129mm a day reducing to 22mm in winter.
The glacier’s movement in most temperate glaciers is enhanced by a process known as basal sliding. Here ‘the immense pressure caused by the weight of the overlying glacial mass causes the ice making contact with the ground to melt because of pressure, despite subzero temperatures, through a process called pressure melting’.
This is an uneven process – melting occurs at the points of most friction – on the ‘stoss’ or up-glacier side of a protuberance. The melt then runs to the leeside of the bump (down-glacier) and refreezes in joints and fractures (see http://www.physicalgeography.net).
Chaotic ice forms in the fracture zone of the Fox Chaotic ice forms in the fracture zone of the Fox Glacier 500m from the terminus. In a year the glacier advances past this point at about 275m (900ft)
Chaotic ice forms in the fracture zone of the Fox Glacier 500m from the terminus. The glacier advances past this point at about 275m (900ft) a year. Summer flows are, not surprisingly, faster than winter flows.
The forward motion and movement of the Fox Glacier is regulated by the seasons and weather as well as overall climate and climatic changes.
In the summer the glacier moves more per day – averaging 0.87m a day – while in the winter this is reduced to 0.64m a day.
So called ‘short term velocity peaks’ also occur due to heavy rainfall. Heavy rain in the winter can cause the glacier to speed up by 44% twenty four hours after the rainfall.
If we take the midpoint between these two rates the hypothetical advance over a year is 275.5m (903ft). This does not result in a corresponding advance of the nose of the glacier due to ‘net radiation and sensible heat contributing energy for surface melt’ (Purdie et al. 2008 p.140).
The shelf ice is thinner than the glacier so to move the same amount of ice it must move faster. The ice “flattens out” and expands when it starts floating.
If the ice is 350 feet thick, then around 315 feet of that is under water. If at any point the water is less than 315 feet deep, the the ice is going to grind along the bottom for a ways.
I hate to burst your bubble, Mark, but the ice is 350 meters thick, not feet. 350 meters is about 1,150 feet in depth/thickness, or 21.875% of a mile. We only get to see the 10% or so above the water line.
Most of the ice cubes in your iced tea show only the very top. The rest is below the water line.
How exactly does your point “burst my bubble”, it just changes the point marginally. Replace water depth with 315 meters instead of 315 feet and the point still stands.
“the ice is going to grind along the bottom for a ways”
No it won’t. There isn’t enough compressive strength in the ice for that. If shelf ice “touches bottom” it sticks and the rest of the shelf flows around it, Here is an image where one can see both how the ice movement speeds up once it reaches the shelf areas (blue/purple) and the “islands” (green) where the ice is stuck:
Well, it isn’t MARGINAL, MarkW. A METER is 3.3 FEET. That means that an ice sheet that is 350 meters top to bottom is 1,155 FEET thick, or 21.875% of a mile.
You can stop being smug any minute now.
So, you are saying 90% of the floating ice, ya know, “ice shelf”, is not below the water? Really?
2hotel9
“SOME” parts of the ice shelves are floating (90% under/10% over, as you would expect). Many sections are resting on all the bedrock and silt under the shallower parts of the coastline – that may mean 50 feet underwater, 200 feet above the water. It depends on where you are on each ice shelf. Just like you cannot “float” in bathtub only 3 inches deep.
If resting on rock/silt surface it is ice sheet, shelf is floating ice. Other point being, if it is so thick it is settling to the sea floor thats a lot of sea ice. At least for a sea that is not supposed to have any sea ice. That means plenty of sea ice, north and south, and it ain’t gonna be gone any time in the foreseeable future. Which is a good thing!
2hotel9
Oh, very true. However, you are making the (seemingly reasonable) assumtion that we actually “know” exactly where the Antarctic “coast” is: That very obvious “coastline” where the “sea level” hits “solid rock.” See, determining where “the solid rock is higher than sea level” requires you to be able to actually “see” the water. Antarctica, larger than Australia, has much (not all!) of its coastline buried under hundreds of feet of fixed glacier ice, moving glacier ice, ice shelves, and ice sheets. Add variable snow to the tens of thousands of miles of unexplored, unmapped coastline with NO vertical surveys, no photos, no underground radar (ground-piercing radar), no seismology surveys (mining is forbidden = why do expensive coal, oil, and gas exploration?), and you end up with “no edge”.
Symptomatic of the problem (or perfectly causing the problem – depending on how yo look at it) is the “fact” that Antarctica is not even “measured” to anything closer than the nearest 1 square kilometer! (14.0 Mkm^2 is the most common area, some sources claim 13.7 Mkm^2, other sources include ice shelves in Antarctica’s area, others add the 1.4 Mkm^2 ice shelves to the 14.0 estimate.) The NSIDC has specifically told me that they do NOT include fixed ice shelves, nor inland fresh water lake ice, in their sea ice totals.
The others are listed more accurately, because we know where the edges are. (Plus or minus a few earthquakes or two.)
Asia – 17,139,445 square miles (44,391,162 square km)
Africa – 11,677,239 square miles (30,244,049 square km)
North America – 9,361,791 square miles (24,247,039 square km)
South America – 6,880,706 square miles (17,821,029 square km)
Actually had this very discussion a few years ago with a woman who is supposed to be a geologist. She told me I am an idiot, of course we know the precise location of the physical coastlines of Antarctica, its on maps. I pointed out that much of that “coastline” on maps is ice and she told me that does not matter. Yes, she is a true believer of the Church of Man Caused Globall Warmining.
Well, surprise surprise, I am with MarkW on this one. His point is essentially unaltered by changing feet to meters.
Wasn’t this the opening scene from that epic movie ‘Day After Tomorrow’? That’s the one where Dennis Quaid leaps across the opening crack and barely makes it. It’s a shame it didn’t crack faster, isn’t it?
Okay, so where do I send in a bid on the ice concession for this summer?
There were a lot of large icebergs in the Southern Ocean throughout the 19th century, something to do with Length of Day (LOD).
In the 19th century the day was 23 hours 56 minutes and 4.1 seconds. Today the day is 23 hours 56 minutes and 4.1 seconds. Doesn’t change much, however since 1972, there have been 27 additional leap seconds added due to irregularities in the Earth’s rate of rotation.
I’m out of my depth, but they mention LOD here.
http://www.warwickhughes.com/climate/Iceberg.htm
Yes. If a lot of ice melts at the poles it means that mass is transferred closer to the Equator which will cause the Earth to rotate slightly slower. It is the opposite effect to a skater who pulls in his/her arms in order to twirl faster.
Then why were there so many icebergs floating in the ocean in the early 1900’s?
It was because intercontinental travel in the 1900’s was by boats, and people were able to SEE them. Today, most intercontinental travel is by airliner, and people can’t SEE them all that much from cruising altitude.
We need to find the real mechanisms involved in Antarctic calving.
I bet it is the same mechanism as in the Arctic, and glaciers.
Antarctic bulls are getting frisky?
Because the icebergs were hunting for ships to sink, silly. I thought everybody knew that.
They don’t go out there now because they aren’t tall enough to knock airplanes out of the sky.
There was apparently two episodes of extremely high iceberg production from Antarctica in the 1860’s and 1890’s. Icebergs actually got as far north as New Zealand (which would certainly be noted today as well).
Very likely some big shelf-ice did break up in Antarctica during the nineteenth century. However nobody was there to see it so no catastrophes ensued (except a few lost ships). It didn’t even create any research programs. A complete flop in fact.
How deep is the rift and how does it compare to the its at point ice thickness of Larsen C? I am not holding my breath in anticipation of a photo worthy enormous iceberg.
How deep is the rift and how does it compare to its at point ice thickness of Larsen C? I am not holding my breath in anticipation of a photo worthy & enormous iceberg.
No engineers were interrupted during this analysis. But you got my attention. It will split off seaward close to where the end of the main crack is. Also, calm down. The shelves are vulnerable to this because of seaward advance and cantilevering of the ice sheet with ocean swells, tides and storms. It’s not melting that causes it.
“Researchers say the loss of a piece a quarter of the size of Wales will leave the whole shelf vulnerable to future break-up.”
Seems to me that the opposite is true. It looks like tidal motions, currents and storm driven waves are stressing the ice where its maximally cantilevered over open ocean. Reducing the mass under stress should make the entire floating sheet less vulnerable to future break-up. Kind of like an earthquake reducing stress along a fault.
EXPLAIN THIS: It appears that the “glaciers” that feed the ice shelf are moving at 0.7 – 0.9 m/day. But, ~50 Km away, in the center of the shelf the ice is moving at 2.0 m/day. Doesn’t this violate the “ice shelf conservation of integrity”? How can the confined center of the shelf be moving faster than the feeding mechanisms?
Please excuse the expression, but shouldn’t there therefore be, “a lot more calfing going on out there?”
1/. Where Climbit Change is concerned, conservation of integrity is violated on a regular basis.
2/. Assuming your tongue was in its normal position, velocity is not conserved in variable width and depth flows. Mass is conserved, but the deeper and wider they become, the slower they are.
That almost has a ‘Yoda’ rhythm to it…
Right, but it goes faster in the deeper, wider portions of the shelf… that is my dilemma at understand the data.
How can the center be the fastest moving part?
How about this for you to ponder? How thick are the glaciers which are moving at 0.7 to 0.9 m/day? How thick is the ice shelf which is moving at 2 m/day. If the center is somewhat less thick than the feed, the linear speed would have to increase to move the same volume of ice per day.
I don’t know if this is the answer or not. I’m too lazy to look it up. This is just a ‘2 seconds of thought’ answer to the question you have posed.
About two weeks ago I visited a temperate glacier, Fox Glacier in NZ.
There is a discussion in this part about the speed of its flow in various places and seasons.
The path to the Fox terminus
The path to the Fox terminus with the Chancellor Ridge behind.
Due to the effects of friction glaciers move fastest in the middle – relative to the valley walls – and at the top – relative to the valley bottom. As the ice flows from the broad névé into the narrow confines of the glacier convergence causes compression in the central section of the glacier. In the Fox Glacier this is also where the ice starts to flow faster as the gradient steepens.
The top 50m of a glacier is known as the fracture zone. Here the ice tends to move in one piece and subsequently is quick to crack into crevasses as gradients change and underlying bedrock features cause stress fractures.
Below 50m the pressure on the ice allows it to move with a plastic flow like a very viscous liquid.
Eroded ice and ground rock at the terminus of the Fox Glacier: summer surface melting averages 129mm a day reducing to 22mm in winter.
Eroded ice and ground rock at the terminus of the Fox Glacier: summer surface melting averages 129mm a day reducing to 22mm in winter.
The glacier’s movement in most temperate glaciers is enhanced by a process known as basal sliding. Here ‘the immense pressure caused by the weight of the overlying glacial mass causes the ice making contact with the ground to melt because of pressure, despite subzero temperatures, through a process called pressure melting’.
This is an uneven process – melting occurs at the points of most friction – on the ‘stoss’ or up-glacier side of a protuberance. The melt then runs to the leeside of the bump (down-glacier) and refreezes in joints and fractures (see http://www.physicalgeography.net).
Chaotic ice forms in the fracture zone of the Fox Chaotic ice forms in the fracture zone of the Fox Glacier 500m from the terminus. In a year the glacier advances past this point at about 275m (900ft)
Chaotic ice forms in the fracture zone of the Fox Glacier 500m from the terminus. The glacier advances past this point at about 275m (900ft) a year. Summer flows are, not surprisingly, faster than winter flows.
The forward motion and movement of the Fox Glacier is regulated by the seasons and weather as well as overall climate and climatic changes.
In the summer the glacier moves more per day – averaging 0.87m a day – while in the winter this is reduced to 0.64m a day.
So called ‘short term velocity peaks’ also occur due to heavy rainfall. Heavy rain in the winter can cause the glacier to speed up by 44% twenty four hours after the rainfall.
If we take the midpoint between these two rates the hypothetical advance over a year is 275.5m (903ft). This does not result in a corresponding advance of the nose of the glacier due to ‘net radiation and sensible heat contributing energy for surface melt’ (Purdie et al. 2008 p.140).
“I don’t know if this is the answer or not.”
It is.
Ice cracks in Antarctica, you say, Professor Luckman? I’m shocked. Shocked, I tell you.
I suggest we have a protest march and all wear funny shaped pink knit hats, in solidarity with the ice!
/s
We could tow this new iceberg up to California into the San Francisco bay and solve the state’s permanent drought and be heros. Oh wait, this years rains took care of the “permanent” drought.
Ok, ok, how about a new plan. They sell our wives sea salt that is better than regular salt. So doesn’t it stand to reason that Iceberg Ice is better than refrigerator ice. We could make millions. Who’s with me? Anyone with distribution experience with large cold objects preferred.
The entirety of Climate Science and related published claims have collapsed into the abyss of “need to publish –> need impact to get published—> for that one needs to find wild, alarmingly scary results —> funding odds increased for next grant submission with impact articles –> so of course wild, scary things will be the conclusion of those studies.”
That is the causal chain of events in Climate and related fields today.
Funding drives the dishonesty.
Dr Lindzen is correct that climate science related funding needs to br cut 90% for next few years to clean out the dishonesty.
There is drought in Africa. Maybe a few Russian nuclear ice breakers could tow that lump of ice there.
IT’S THE BLIMEY CRACK IN THE WORLD HE SAYS!
Well I always said ‘renewable’ energy was a total disaster…..
Obligatory “Day After Tomorrow” quote…
Wow you did have a lot of snow in New York last month – love the spelling “Tomarrow”.
So nice to realize that there is beautiful dramatic music as the world ends. Makes me feel a lot better about everything:)
I wonder what such ice is supposed to do.
I see N possibilities:
a. It will do the thing we see it doing over and over;
b. It will do nothing forever;
c. It will melt when the temperature gets above freezing;
…
n-1. It will sublimate if the temperature stays below freezing;
N …
My computer just flashed the answer: n = 42
Now working on the time to accomplish each; that answer also looks to be 42
Now checking to see if the OS needs an update …
Check the Improbability Drive John. It seems to be frozen. If it thaws out you just may find yourself on Vogsphere being slapped in the face for thinking how to get home.
Whatever you do, don’t panic. And remember to bring a towel.
If ice cracked before aircraft and satellites were invented did it make a visual. If a tree falls in the forest and no one hears it did it make a sound. If a man talks alone in the wilderness and no woman hears him is he still wrong?
Wow. What is in effect a super massive giant grounded iceberg is going to crack and calve off a merely giant iceberg. Will someone please explain how this is part of a crisis?
In the UK, “an area the size of Wales” has traditionally been used as a unit of measurement of loss of Amazon Rain Forest. I guess they’re moving with the times.
You know if I add ice to my glass of tea, the tea gets colder. The ice melts, of course, which opens up that whole business of heat transfer, which is the whole point to dropping ice into your iced tea. But if you tell these ‘climate guys’ about the physics involved in transfer of thermal energy, will their eyes glaze over? Or will they have hysterical fits and start screaming foul epithets at you?
Perhaps they will make it into a theme park ride. Should be exciting when it rides the circumpolar current all the way round, and reaches the tip of South America.
OMG change is happening!
Argentina got jealous of the Canadian iceberg and wanted its own.
Gosh, I wonder what will happen when Warmists discover the San Andreas Fault?
I can see the headlines in a few years.
” Unprecedented 7.0 earthquake shakes California. CO2 blamed.”
Too Late! – http://www.youtube.com/watch?v=gixWSojcUkE
At the flow rates charted the ice of the shelf is only two or three centuries old, and nobody knows how long the shelf has been there except as may be inferred by sea level reconstruction, GIA, and assumptions of climate stability. Jansen et al considered Larsen C to be stable back in 2010 ( https://www.igsoc.org/journal/56/198/j10J001.pdf ), and this rift has little bearing on that assumption–the shelf will be replenished.
BTW, even these WAIS modeling doomsayers took the LIA for granted back in 1981 (p.521): http://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1155&context=ers_facpub
That is, like all glaciologists, they paid no attention to the hockey stick. –AGF
I visited Wales many years ago as a practically penniless student and was severely short-changed in a shop in Cardiff. I then found that I had insufficient funds to buy a rail ticket to London. I had to spend a day and a half hitch-hiking in the rain to get there. So I am praying that this article is wrong and it is actually Wales splitting off from England with the former eventually floating off in the Gulf Stream to Iceland!
Actually what I dont quite understand is:-
if the ice shelf breaks up, it is because of glacial movement, which in turn is caused by the pressure of snow accumulation over the catchment area.
Therefore if the snow in the catchment area, which gradually turns to ice, is accreting, surely the flow to the sea and the pressure on the ice shelf must increase the likelihood of the iceshelf calving.
The whole thing seems just as likely that Antarctica is growing which it appears it is.
I mean thats what wikipedia is saying. How can we argue with that?
https://en.wikipedia.org/wiki/Antarctic_ice_sheet
Cheers
Roger
http://www.rogerfromnewzealand.wordpress.com
” the flow to the sea and the pressure on the ice shelf must increase the likelihood of the iceshelf calving”
Indeet. The probability is exactly 100%. Otherwise the whole southern ocean would be covered by shelf-ice
Thanks, that much I understand.
What the question is:- Is the rate increase of calving of an ice shelf a symptom of warming temperatures and the glaciers flow faster or slower because of less snow in the catchment or is it a symptom of an increase of snow accretion in the catchment area and a build up of pressure which increases the glacial pressure at sea level?
I suppose one could simplify the question to “is an increase in calving rate good or bad”.
Cheers
Roger
“…holding back the flow of glaciers that feed into it.”
I don’t see how that is mechanically possible. If it is breaking AWAY then it is clearly NOT holding back the flow and never was.