The wailing today is that the collapse of the Antarctic ice sheet has already begun.
It’s pretty bad when other environmental reporters start calling you out on it, such as NYT’s Andrew Revkin did today.
Awful misuse of "Collapse" in headlines on centuries-long ice loss in W. Antarctica. See rates in papers. Same as '09 http://t.co/kk48ztySvZ
— Andrew Revkin 🌎 ✍🏼 🪕 ☮️ (@Revkin) May 12, 2014
Yes, a slow affair indeed. Truly an abuse of the headline. Buried below the headline in the article, there is agreement with Revkin:
But the researchers said that even though such a rise could not be stopped, it is still several centuries off, and potentially up to 1,000 years away.
A lot can happen in several centuries, why even in the last couple of years Antarctic has seen record levels on Antarctic sea ice.
And the temperature isn’t cooperating either:
RSS Southern Polar Temperature Lower Troposphere (TLT) – 1979 to Present for the area where sea ice forms (60 to 70S)
Remote Sensing Systems (RSS) – Microwave Sounding Units (MSU) – Click the pic to view at source
[previous graph removed – wrong latitude span and no replacement, my mistake -Anthony]
UPDATE: Revkin gives more reasoning on “collapse” here:
Consider Clashing Scientific and Societal Meanings of ‘Collapse’ When Reading Antarctic Ice News
Here is the paper the claim is based on:
Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011.
Abstract
We measure the grounding line retreat of glaciers draining the Amundsen Sea Embayment of West Antarctica using Earth Remote Sensing (ERS-1/2) satellite radar interferometry from 1992 to 2011. Pine Island Glacier retreated 31 km at its center, with most retreat in 2005–2009 when the glacier un-grounded from its ice plain. Thwaites Glacier retreated 14 km along its fast-flow core and 1 to 9 km along the sides. Haynes Glacier retreated 10 km along its flanks. Smith/Kohler glaciers retreated the most, 35 km along its ice plain, and its ice shelf pinning points are vanishing. These rapid retreats proceed along regions of retrograde bed elevation mapped at a high spatial resolution using a mass conservation technique (MC) that removes residual ambiguities from prior mappings. Upstream of the 2011 grounding line positions, we find no major bed obstacle that would prevent the glaciers from further retreat and draw down the entire basin.
And here is the press release from AGU:
New study indicates loss of West Antarctic glaciers appears unstoppable
12 May 2014
Joint Release
WASHINGTON, D.C. — A new study finds a rapidly melting section of the West Antarctic Ice Sheet appears to be in an irreversible state of decline, with nothing to stop the glaciers in this area from melting into the sea.
The study presents multiple lines of evidence, incorporating 40 years of observations that indicate the glaciers in the Amundsen Sea sector of West Antarctica “have passed the point of no return,” according to glaciologist and lead author Eric Rignot, of the University of California Irvine and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. The new study has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
These glaciers already contribute significantly to sea level rise, releasing almost as much ice into the ocean annually as the entire Greenland Ice Sheet. They contain enough ice to raise global sea level by 4 feet (1.2 meters) and are melting faster than most scientists had expected. Rignot said these findings will require an upward revision to current predictions of sea level rise.
“This sector will be a major contributor to sea level rise in the decades and centuries to come,” Rignot said. “A conservative estimate is it could take several centuries for all of the ice to flow into the sea.”
Three major lines of evidence point to the glaciers’ eventual demise: the changes in their flow speeds, how much of each glacier floats on seawater, and the slope of the terrain they are flowing over and its depth below sea level. In a paper published in Geophysical Research Letters in April, Rignot’s research group discussed the steadily increasing flow speeds of these glaciers over the past 40 years. This new study examines the other two lines of evidence.
The glaciers flow out from land to the ocean, with their leading edges afloat on the seawater. The point on a glacier where it first loses contact with land is called the grounding line. Nearly all glacier melt occurs on the underside of the glacier beyond the grounding line, on the section floating on seawater.
Just as a grounded boat can float again on shallow water if it is made lighter, a glacier can float over an area where it used to be grounded if it becomes lighter, which it does by melting or by the thinning effects of the glacier stretching out. The Antarctic glaciers studied by Rignot’s group have thinned so much they are now floating above places where they used to sit solidly on land, which means their grounding lines are retreating inland.
“The grounding line is buried under a thousand or more meters of ice, so it is incredibly challenging for a human observer on the ice sheet surface to figure out exactly where the transition is,” Rignot said. “This analysis is best done using satellite techniques.”
The team used radar observations captured between 1992 and 2011 by the European Earth Remote Sensing (ERS-1 and -2) satellites to map the grounding lines’ retreat inland. The satellites use a technique called radar interferometry, which enables scientists to measure very precisely — within less than a quarter of an inch — how much Earth’s surface is moving. Glaciers move horizontally as they flow downstream, but their floating portions also rise and fall vertically with changes in the tides. Rignot and his team, which includes researchers from UC Irvine and JPL, mapped how far inland these vertical motions extend to locate the grounding lines.
The accelerating flow speeds and retreating grounding lines reinforce each other. As glaciers flow faster, they stretch out and thin, which reduces their weight and lifts them farther off the bedrock. As the grounding line retreats and more of the glacier becomes waterborne, there’s less resistance underneath, so the flow accelerates.
Slowing or stopping these changes requires pinning points — bumps or hills rising from the glacier bed that snag the ice from underneath. To locate these points, researchers produced a more accurate map of bed elevation that combines ice velocity data from ERS-1 and -2 and ice thickness data from NASA’s Operation IceBridge mission and other airborne campaigns. The results confirm no pinning points are present upstream of the present grounding lines in five of the six glaciers. Only Haynes Glacier has major bedrock obstructions upstream, but it drains a small sector and is retreating as rapidly as the other glaciers.
The bedrock topography is another key to the fate of the ice in this basin. All the glacier beds slope deeper below sea level as they extend farther inland. As the glaciers retreat, they cannot escape the reach of the ocean, and the warm water will keep melting them even more rapidly.
The accelerating flow rates, lack of pinning points and sloping bedrock all point to one conclusion, Rignot said.
“The collapse of this sector of West Antarctica appears to be unstoppable,” he said. “The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating sections of the glaciers. At this point, the end of this sector appears to be inevitable.”
Because of the importance of this part of West Antarctica, NASA’s Operation IceBridge will continue to monitor its evolution closely during this year’s Antarctica deployment, which begins in October. IceBridge uses a specialized fleet of research aircraft and the most sophisticated suite of science instruments ever assembled to characterize changes in thickness of glaciers, ice sheets and sea ice.
For additional images and video related to this new finding, visit: http://go.nasa.gov/1m6YZSf
For additional information on the West Antarctic Ice Sheet and its potential contribution to sea level rise, visit: http://go.nasa.gov/1oIfSlO
For more information on Operation IceBridge, visit: http://www.nasa.gov/icebridge
###
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What they forget to mention with any collapse is the extreme snowfalls which have already taken place and, according to the IPCC, a likely to increase this century on Antarctica. This would offset any sea level rise.
Extreme snowfalls recorded in recent years – Antarctica
http://onlinelibrary.wiley.com/doi/10.1002/grl.50559/abstract
http://onlinelibrary.wiley.com/doi/10.1029/2012GL053316/abstract
@conscious1 Thanks for the response. Maybe I missed the blog post that went over all the nitty-gritty stuff.
A Primer, As-Ordered.
But there are actually five different “ice” geometries. If you confuse approximation appropriate (somewhat) to one to the others, you can get very, very confused. (Or re-educated,as the CAGW religion desires, that is.)
From the interior out towards the sea. But let’s start below sea level, since the “central Greenland” AND Antarctic basins – the rock that is the “bottom” of the ice caps in these regions ARE below sea level near their centers. So, we have a very, very wide “bowl” of bare rock, very, very gradually sloping from the coastal mountain ranges DOWN towards a low point below sea level, then very, very gradually sloping back UP towards the mountain ranges that form the the other boundary.
Imagine, if you will, the tops of the Appalachians in eastern NY stae, then sloping down towards Lake Eire and Lake Ontario (“sea level”) then under those lakes to their rocky bottoms and back up towards another east-west mountain range north of Lake Ontario. the BARE ROCK (NOT the top of the ice caps!) looks like a very large, immense but very, very shallow “saucer” with high bare ridges on both sides, and a low area in the middle. (The middle of the saucer happens to be below sea level. )
Now, the walls of this 2000 kilometer-wide saucer are only 2 – 3 kilometers high! Bare rock (now) but “only” 1, 2, and 3 kilometers high! (The “valleys” (passes) between the peaks are “lower” than the maximums obviously, but still high above sea level, and the peaks are higher yet.) Now, if I fill the center of this 2000 kilometer wide “saucer” with jello (gelatin, pudding, or the semi-solid food of your choice) I can fill the center higher than the edges, right? So, this sticky, not-very fluid, “ice” is the continetntal ice cap of both Greenland and Antarctica. Its center is below sea level, squished in place by the 3300 meter high spot, trapped but not-perfectly-rigidily-in-place by the hig coastal mountains surrounding a center valley whose center is below sea level.
BUT THE SLOPE OF THIS ICE CAP CANNOT “MOVE” ICE. The “ice” is trapped by the high mountain ranges on all sides (with a very, very few “valleys where the ice can slowly flow out) and MUST stay in place. The “slope” of this central high ice cap “slope” – at 1/1000 slope. ZERO. Now, it would appear that the “cie” would flow out from the center towards the sea, but the friction of the ice against the rock below, the nearly zero slope of the center “peak” against a rocky, mountainous edge higher than the central peak, and the near-zero “sideways force” of a near-zero slope trying to move ice “uphill” towards these boundary ridges mean that the central ice cannot move.
What is deposited by snowfall, rain, ice, and precipitation is lost by sublimation, evaporation, and meltwater going down under the icecap and then slowly out through the valleys thousands of kilometers away.
So, meltwater.
Supposedly, meltwater under glaciers “accelerates” them by reducing friction. In Alpine glaciers 1/4 kilometer to 1 kilometer wide, meltwater has occasionally DOES speed up glaciers downhill. Then it promptly goes away through the lowest flowing path under the glacier between the glacier and the bedrock, and LEAVES. Meltwater CANNOT “build up” into a multi-tens-and-hundreds-of-kilometer-wide slick and perfectly lubricated luge track speeding that thousand-kilometer wide ice cap downhill (actually “uphill”) against the sloping bedrock!
Area of Greenland ice cap = 17.0 Mkm^2.
Area of Antarctic ice cap = 14.0 Mkm^2.
NEITHER cie cap gas a CONSTANT thickness nor weight nor cross-section. Keep ALWAYS that 1:1000 slope of their upper ice surface. And the mountain ranges that trap both on all sides: north, east, south, and west.
Second type of ice: Classic Alpine Glacier.
Very, very steeply sloped, very narrow “river” of ice. Well-defined start point -> high against a very high bare rock wall ABOVE a sloping glacier valley aimed directly downhill to a warmer outlet below. NEVER longer than the mountain it started against. Usually 5 kilometer to 25 kilometer long. Very, very few longer 25-30 kilometers. Some even only 1-2 kilometer long.
This is the “glacier ice” you have been indoctrinated into believing exist everywhere. It doesn’t. The Alpine glaciers around Greenland and in some places around Antarctica are just that: AROUND the edges of that continent and island. They do move at varying rates at different times. they do melt and retreat whenever deposits at the top are less than melting at the bottom. they move directly proportional the difference in height of absolute top and absolute bottom, friction level between bottom and middle, and the “sharpness” of their entrapping valley walls.
South pole is 90 degrees south, not zero. You have shown the TLT data from the equator to 70 degrees south. Eric Swanson, pointed this out to Eli. FWIW 60-70 will cover the edge of the continent.
http://www.iup.uni-bremen.de:8084/amsr2/antarctic_AMSR2_visual.png
[simple typo in choosing the graph from the FTP site – removed since there is no coverage over the S pole -Anthony]
Let us continue with the requested “Primer” ….
Continental Shelf Ice. Very, very thick but fragmented and compressed ice.
Shelf Ice extends (obviously!) from the surface down to bedrock, OR from the surface down to the bottom edge of the floating shelf ice. The ice shelf can ONLY “ground” against the bedrock on the ocean floor where the ocean is “shallow” enough (close enough so the the 0,0 of the sea floor) so that the ice that is underwater can touch the ocean floor. Assume you have a 100 meter thick “ice shelf” on a constantly-sloping perfectly even rock bedrock. At the intersection of bedrock and sealevel, the ice shelf is 100 meter thick, the top of ice is 100 meters ASL.
We move out to sea a little ways. The ice shelf is still 100 meters thick, but the top of bedrock is at sea level – 50 meters. The ice shelf is grounded still on bedrock, but is “at sea, right? But it ISN’T “floating” at all, it is stuck fast against the sea floor bu the 50 meters weight of ice above sea level. “hot water” under this mass of sea ice “might” melt it some, but that “hot water” needs to be constantly replaced (or it will freeze out by the -54 degree air temperature keeping the top of ice shelf ice at -54 degree C. )
Now, let’s more to 75 meters sea floor bottom. Bottom of ice shelf = -75 meters. Top of ice shelf = 25 meters. Same as at 50 metrs depth.
But, at -90 meters depth or deeper, the ice MUST start floating. Or begin freezing above up on top so that it gets thicker, gets heavier, and is forced deeper. Top of ice shelf above sea level cannot be higher than 1/10 sea floor depth, or the ice shelf will begin floating. Its edge might get pushed out into shallower water, or into a bay or inlet or up against an off-shore island, but the ice shelf itself will always be either gaining mass and getting forced down against the seafloor, losing mass and beginning to float up off the sea floor, or be already heavier (thicker than 90% of the sea floor depth) than seawater and be grounded firmly into the sea floor rock and debris.
Note: The NSIDC has assured me that the they do NOT include ice shelves – off of Greenland AND off of Antarctica as a partof “sea ice”. Great Lakes “freshwater” sea ice is also NOT included in their daily reports of sea cie extents and sea ice area.
Sea Ice. This ice is always floating on the sea surface. Freezing out from the air cooling the top of the water, or from the air cooling the top of sea ice, then this heat energy moving up through he existing sea ice from the hot water (2-4 degree C) to the bottom of the existing sea ice.
Sea ice varies through the year. Sea ice might be blown up against continental ice, and might be (almost always, actually) touching or bumping against grounded or floating shelf ice, but is not a part of either system Glacier ice flowing out of a glacier valley into the sea moves and drops off small icebergs into the sea ice, which just gets moved sideways and bumped away from the glacier.
The rest of the blogosphere is chuckling over “70S to the pole”. The graph says “70S to 0.0”, which is from 70 degrees south to the EQUATOR. RSS apparently doesn’t cover the pole, because of the orbit it’s in.
[REPLY: And it was removed. Mr. Thorstensen. I’ll chuckle over the fact that you think RSS is “in orbit”. – Anthony]
Typical liberal BS. Make it up as you go, lie, lie, lie. Now all those gullible inferior thinking liberal losers are running around screaming “The sky is falling”. How irresponsible but then it is all about fake science, pushing propaganda, and the religion of Globally Warming/Climate Change or whatever they are calling it lately. These liberal control freaks will do and say any breaking lie
More on the undersea volcano in West Antarctica.
http://www.thesundaytimes.co.uk/sto/news/uk_news/Environment/article1409368.ece
Notice that Suzanne Goldenberg’s story on this in the Guardian has comments turned off. Hmmmm.
Re Jimbo says: May 12, 2014 at 4:56 pm
Captain, the ice is breaking up.
The 1929 paper linked here:
http://www.jstor.org/discover/10.2307/208079?uid=2&uid=4&sid=21103345664011
contains an interesting sentence that might offer a clue to when the term “El Niño” came into general use:
“He shows that the Humboldt Current must have been deflected westwards early in 1925, allowing the warm coastal waters from the Bay of Panama, i.e. the countercurrent El Niño, to penetrate southwards along the coast and tuns cause an abnormal rainfall along the arid coasts of Ecuador, Peru, and Chile.”