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The 'Larsen Ice Shelf' () is a long, fringing ice shelf in the northwest part of the Weddell Sea, extending along the east coast of Antarctic Peninsula from Cape Longing to the area just southward of Hearst Island. Named for Captain Carl Anton Larsen, who sailed along the ice front in the ''Jason'' as far as 68°10'S during December 1893.
In finer detail, the 'Larsen Ice Shelf' is a series of three shelves that occupy (or occupied) distinct embayments along the coast. From north to south, the three segments are called Larsen A (the smallest), Larsen B, and Larsen C (the largest) by researchers who work in the area. The Larsen A ice shelf disintegrated in January of 1995. The Larsen B ice shelf disintegrated in February of 2002. The Larsen C ice shelf appears to be stable.
The Larsen disintegration events were unusual. Typically, ice shelves lose mass by iceberg calving and by melting at their upper and lower surfaces. The disintegration events are linked to the ongoing climate warming in the Antarctic Peninsula, about 0.5 °C per decade since the late 1940's as result of global warming. [1]

Contents

Larsen B ice shelf

Popular culture

See also

External links and references

Larsen B ice shelf

During 2002-01-31–2002-03-07 the Larsen B ice shelf collapsed and broke up. 3,250 km² of ice 220 m thick broke off. The shelf could have been stable for up to 12,000 years ago, essentially the entire Holocene period since the last ice age, according to Queen's University researchers [2]. By contrast, the Larsen A Ice Shelf "was absent for a significant part of that period and reformed beginning about 4,000 years ago, according to the study".
Despite its great age, the Larsen B was clearly in trouble at the time of the collapse. With warm currents eating away the underside of the shelf it had become a "hotspot of global warming"(Fred Pearce The Last Generation p92). What however took glaciologists by surprise was the rapidness of the breakup - a mere three days. The factor they had ignored was water. Melted water having formed on the surface slipped down into cracks and then, acting as wedges, leavered the shelf apart.(Fred Pearce The Last Generation p92)
This collapse has revealed a thriving ecosystem 800 m (half a mile) below the sea. "Despite near freezing and sunless conditions, a community of clams and a thin layer of bacterial mats are flourishing in undersea sediments. [...] The discovery was accidental. U.S. Antarctic Program scientists were in the northwestern Weddell Sea investigating the sediment record in a deep glacial trough twice the size of Texas. [3].

Popular culture

The Larsen B Ice Shelf is the subject of a song by the band British Sea Power. "Oh Larsen B" appears on their 2005 album ''Open Season'', and contains the lyric ''"my favourite foremost coastal Antarctic shelf ... oh Larsen B, oh won't you fall on me ... desalinate the barren sea"''. Often mis-quoted as "desalinate the Barents Sea" which has caused confusion as the Barents Sea is in the Arctic.
The ice shelf has also been made the subject of a song by instrumental metal/drone band 5ive. The song, ''"Sleep For The Larsen B Shelf,"'' appears on their ''The Telestic Disfracture'' album.
Larsen B Ice Shelf appeared also in the 2004 film ''The Day After Tomorrow'' where a huge chunk of ice fell off as Hall proclaimed 'the last chunk of ice that fell off was about the size of Rhode Island'. This opening sequence paves the way for the events to follow in the rest of the film.
The disintegration of the shelf is referenced in Al Gore's environmental documentary film ''An Inconvenient Truth'' as evidence in support of global warming.

See also

★ List of glaciers and ice shelves in Antarctica

External links and references

★ U.S. National Snow and Ice Data Center

★ Instituto Antártico Argentino

★ Animation of Larsen B breakup, 31 January to 7 March 2002

★ warmest summer on record leads to disintegration

★ Public Release, 3 August 2005, "Ice shelf disintegration threatens environment, Queens study"

★ ''The Independent'', 4 August 2005, "Ice shelf collapse was biggest for 10,000 years"