[Zardoz]

Lots of deniers in here.

Notice how they seem to be chronically pissed off? They aren't happy about what's going on around them. They want their status quo maintained for the rest of their lives, and they find us realists to be extremely annoying.

They really want us to just shut up and join them in their denial state. It frosts them that we refuse.

[rockdoc123]

What is important here is not whether there is loss of ice in the Arctic but rather whether or not this is somehow unprecedented and if so what is the direct link to AGW theory.
It is fairly well documented that Ellesmere Island ice shelves have been breaking up throughout the 20th century, well before the recent warming from the mid seventies to present.

Jefferies, M.O., 1986, Ice Island Calvings and Ice Shelf Changes, Milne Ice Shelf and Ayles Ice Shelf, Ellesmere Island, N.W.T., Arctic, V. 39, p. 15-19

indicated that :

..the largest observed ice island calving occurred at Ward Hunt Ice Shelf where almost 600 km2 of ice broke away at some time between August 1961 and April 1963.

Note this was a relatively cool period with average temperatures having dropped from their high point in the late thirties (when they were close to current average temps). He also noted that 48km2 of calving occurred on the Ayles and Milne Ice shelves between 1959 and 1974. The important point is that the current ice extent is about 10% of what it was at the turn of the century, most of the calving occurred prior to the recent warming in the latter part of the 20th century.
An important point is that satellite coverage did not commence until 1978 so actual measures of sea ice extent prior to that are poorly constrained. What we do know is that the Northwest passage was navigated quite easily at the turn of the 20th century (Amundsen in 1905) and again in the early 1940’s whereas that has not been possible in the intervening years. That would mean that the sea ice extent has probably fluctuated quite considerably throughout the entirety of the 20th century. We also know that the current Ward ice shelf formed during the cooling period after the Holcene warm event and prior to that warm event the area was covered by ice. We also need to keep in mind that the disintegration of ice shelves can have a number of underlying mechanisms other than climate change including wind, wave and tidal action.
Tying anything that is going on in the Arctic or for that matter Antarctic to AGW theory requires some particular special pleading I think. Occam’s razor principle would suggest “natural variability” as the most reasonable plea given the history.

[xironman]

http://en.wikipedia.org/wiki/Roald_Amundsen

During this time Amundsen learned from the local Netsilik people about Arctic survival skills that would later prove useful. For example, he learned to use sled dogs and to wear animal skins en lieu of heavy, woolen parkas. After a third winter trapped in the ice, Amundsen was able to navigate a passage into the Beaufort Sea after which he cleared into the Bering Strait, thus having successfully navigated the Northwest Passage.[1] Continuing to the south of Victoria Island, the ship cleared the Canadian Arctic Archipelago on August 17, 1905, but had to stop for the winter before going on to Nome on the Alaska Territory's Pacific coast. Five hundred miles (800 km) away, Eagle City, Alaska, had a telegraph station; Amundsen travelled there (and back) overland to wire a success message (collect) on December 5, 1905.

Three years of hunting and pecking for breaks in the ice is easy? I would hate to see what hard is.

[dohboi]

Proudfossil wrote:

"you dumb MFR dohboi."

Reverting to obscene epithets is equivalent to conceding defeat, as it shows you have run out of rational arguments.

I had forgotten that the next stage after denial is anger. I guess we're seeing this here. Maybe that's a good sign, that we've nudged this fellow along the path to pure doomerism? Listen and learn, Grasshopper.

[rockdoc123]

Three years of hunting and pecking for breaks in the ice is easy? I would hate to see what hard is.

consider the fact they had nothing other than compass and sextant to navigate by. Unlike today they would not have access to airphotos or satellite images that would indicate the way to open water. The fact they found open passage suggests they were extremely lucky (too much to imagine I'm afraid) or that there was considerable open sea areas and they happened to be close to one.

[xironman]

Last year the passage was completely open, no problem whatsoever. What they found were naturally occurring breaks in the ice cover, given enough time you could work your way across.

[Tuike]

Antarctic ice shelf set to collapse due to warming

But it is held together only by an ever-thinning 40-km (25-mile) strip of ice that has eroded to an hour-glass shape just 500 meters wide at its narrowest.

In 1950, the strip was almost 100 km wide.

"It really could go at any minute," Vaughan said on slushy snow in bright sunshine beside a red Twin Otter plane that landed on skis. He added that the ice bridge could linger weeks or months.

The Wilkins once covered 16,000 sq km (6,000 sq miles). It has lost a third of its area but is still about the size of Jamaica or the U.S. state of Connecticut. Once the strip breaks up, the sea is likely to sweep away much of the remaining ice.

[essex]

It most likely will break up as it has done many times in the past. The Wilkins ice shelf is a minute part of Antarctica. Off the coast of the South island of New Zealand there are deep gouges in the sea bed which have been created by huge ice bergs. The melting ice bergs will not add to sea levels. The ice shelf is fed by glaciers which are in turn fed by snow fall. If no ice ever made its way back to the sea to melt then the ice on the continent would grow forever.
Oh, and by the way its summer in Antarctica.

[bratticus]

Fractured but still in one piece.

Keeping an eye on Wilkins Ice Shelf
ESA

In late November [2008], new rifts developed on the ice shelf that scientists warn could lead to the opening of the ice bridge that connects the ice shelf to the Charcot island. If the ice bridge were to open, it could put the entire ice shelf at risk of further disintegrating.

The early part of 2009 is the warmer part of the year for the antarctic.

economic collapse -> factory emissions plunge -> global warming backs off a bit -> Wilkins break up is put on hold -> those with a vested interest in global warming protest this claim

[Tanada]

Fractured but still in one piece.

The early part of 2009 is the warmer part of the year for the antarctic.

economic collapse -> factory emissions plunge -> global warming backs off a bit -> Wilkins break up is put on hold -> those with a vested interest in global warming protest this claim

Personally I find the fact that the sliver was still in place Friday the 13th to be a GOOD thing, and I don't much see how anyone can feel its a bad thing.

[kiwichick]

if the recession causes lower emissions it will probably increase GW by reducing the dimming effect

[Tanada]

While the ESA image for yesterday still shows the thread in place Spains scientists reports it is no longer holding back the breakup, which is now underway. NEWS

Over the past two weeks, the scientists have seen the ice shelf on the edge of the Belinghausen Sea recede 550km and have noted that the water temperatures are extraordinarily warm in this area.

Experts have warned that the breaking away of this massive ice shelf will ultimately have notable consequences on the sea level.

edited to fix typo

[Homesteader]

From the same article:

"In the past 50 years, Antarctica has seen the greatest temperature increase across the whole planet: 0.5 degrees centigrade per decade, and the area is seeing a dramatic loss of ice, much greater even than scientists had anticipated."

[galacticsurfer]

http://www.elpais.com/articulo/sociedad ... soc_10/Tes

http://www.europapress.es/ciencia-00298 ... 83523.html

"Más o menos se calcula que la superficie de la placa que ya ha empezado a navegar por el Mar de Belinghausen representa probablemente 1/4 parte de la extensión total y al menos durante las próximas dos ó tres semanas aumentará la proporción de la placa Wilkins que se desprende de la placa central y que se dispersa hacia el mar", explicó Duarte, al tiempo que puntualizó que la plataforma de hielo situada en el Polo Sur comenzó a cuartearse hace un año.

25% of Wilkins is now gone.

[Tanada]

http://www.elpais.com/articulo/sociedad/Antartida/resquebraja/elpepusoc/20090218elpepisoc_10/Tes

http://www.europapress.es/ciencia-00298 ... 83523.html

"Más o menos se calcula que la superficie de la placa que ya ha empezado a navegar por el Mar de Belinghausen representa probablemente 1/4 parte de la extensión total y al menos durante las próximas dos ó tres semanas aumentará la proporción de la placa Wilkins que se desprende de la placa central y que se dispersa hacia el mar", explicó Duarte, al tiempo que puntualizó que la plataforma de hielo situada en el Polo Sur comenzó a cuartearse hace un año.

25% of Wilkins is now gone.

No hable Espanol...nee' Italiano

[galacticsurfer]

German scientists confirm by satellite Terrasar that no such collapse has occurred. False alarm.

http://www.20min.ch/news/wissen/story/D ... t-23998412

Forscherstreit
Die Antarktis zerbröselt nicht
Spanische Forscher wollen beobachtet haben, dass der riesige Wilkins-Eisschild in der Antarktis zerbrochen ist. Deutsche Wissenschaftler dementieren: Auf Satellitenbildern ist kein grosser Abbruch zu erkennen.

Das staatliche spanische Forschungsinstitut CSIC hatte am Dienstag berichtet, dass sich eine Fläche von 14 000 Quadratkilometern vom Wilkins-Eissschelf abgelöst habe und in mehrere Eisberge auseinandergebrochen sei. Die Spanier bezifferten die Gesamtgrösse des Schelfs auf über 16 000 Quadratkilometer.

Auf den Bildern des deutschen Satelliten TerraSar und des europäischen Satelliten Envisat sei derzeit kein neuer grosser Abbruch am Wilkins-Eisschelf zu sehen, entgegnete am Mittwoch die Glaziologin Angelika Humbert von der Universität Münster auf Anfrage der Deutschen Presseagentur DPA.

Es gebe zwar einen sehr fragilen Eissteg vom Schelf zum Festland der Antarktis, erläuterte Humbert. «Wann dieser bricht, ist jedoch noch nicht vorherzusagen.» In der Folge könnte je nach Entwicklung eine 500 bis 3800 Quadratkilometer grosse Eisfläche zerfallen.

[Tanada]

Three news item about the Wilkins ice shelf caught my attention last night, here they are for everyone interested to read.
Science Daily

The Advanced Synthetic Aperture Radar (ASAR) images acquired on 2 April by ESA’s Envisat satellite confirm that the rifts are quickly expanding along the ice bridge.

Dr Angelika Humbert from the Institute of Geophysics, Münster University, and Dr Matthias Braun from the Center for Remote Sensing, University of Bonn, witnessed the recent development during their daily monitoring activities of the ice sheet using data from Envisat and the German Aerospace Center’s TerraSAR-X satellite.

AP

Originally covering about 5,000 square miles (13,000 square kilometers), the ice shelf lost 14 percent of its mass last year alone, the statement quotes a scientist Angelika Humbert of Germany's Munster University as saying.

In two 2008 incidents, large chunks of the ice bridge fell away, shaving it down to just 985 yards (900 meters) across at its narrowest, the statement said.

As a result, "In the past months, we have observed the ice bridge deforming and its narrowest location acting as a kind of hinge," Humbert is quoted as saying.

Scientist are examining whether global warming is behind the shelf's breakup, the statement said. Average temperatures in the Antarctic Peninsula have risen by 3.8 degrees Farenheit (2.5 degrees Celsius) over the past half century, the statement said — higher than the average global rise.

On the Net:
ESA "Webcam from space": ESA LINK

CNN

Several of these ice shelves, including seven in the past 20 years, have retreated and disintegrated.

The Wilkins Ice Shelf had been stable for most of the past century before it began retreating in the 1990s.

"It had been there almost unchanged since the first expeditions which mapped it back in the 1930s, so it had a very long period of real stability, and it's only in the last decade that it's started to retreat," Vaughan said.

Wilkins is the size of the state of Connecticut, or about half the area of Scotland. It is the largest ice shelf on the Antarctic Peninsula yet to be threatened.

If the ice shelf breaks away from the peninsula, it will not cause a rise in sea level because it is already floating, scientists say. Some plants and animals may have to adapt to the collapse.

The Antarctic Peninsula is the piece of the continent that stretches toward South America.

[Graeme]

And this from NYT today:

Ice Bridge Holding Antarctic Shelf in Place Shatters

An ice bridge holding a vast Antarctic ice shelf in place has shattered and may herald a wider collapse caused by global warming, a scientist said Saturday.

“It’s amazing how the ice has ruptured,” said David Vaughan, a glaciologist with the British Antarctic Survey. “Two days ago it was intact,” he said, referring to a satellite image of the Wilkins ice shelf.

http://www.nytimes.com/2009/04/05/science/earth/05antarctica.html

[Tanada]

That last shot on the EU sat sequence is remarkable, nearly the entire connection has shattered and is spreading into seperate bergs. I wonder how losing the pressure on the shelf will effect things? I have read everything from a minor shelf loss to a total collapse as being predicted when the bridge failed.

[GregWatson]

Sure looks like it is finished.