Ice Apocalypse

Ice Apocalypse

SOURCE: Grist DATE: November 21, 2017 SNIP: The glaciers of Pine Island Bay are two of the largest and fastest-melting in Antarctica. (A Rolling Stone feature earlier this year dubbed Thwaites “The Doomsday Glacier.”) Together, they act as a plug holding back enough ice to pour 11 feet of sea-level rise into the world’s oceans — an amount that would submerge every coastal city on the planet. For that reason, finding out how fast these glaciers will collapse is one of the most important scientific questions in the world today. In the past few years, scientists have identified marine ice-cliff instability as a feedback loop that could kickstart the disintegration of the entire West Antarctic ice sheet this century — much more quickly than previously thought. A wholesale collapse of Pine Island and Thwaites would set off a catastrophe. Giant icebergs would stream away from Antarctica like a parade of frozen soldiers. All over the world, high tides would creep higher, slowly burying every shoreline on the planet, flooding coastal cities and creating hundreds of millions of climate refugees. All this could play out in a mere 20 to 50 years — much too quickly for humanity to adapt. “It could happen faster or slower, I don’t think we really know yet,” says Jeremy Bassis, a leading ice sheet scientist at the University of Michigan. “But it’s within the realm of possibility, and that’s kind of a scary thing.” There’s a recurring theme throughout these scientists’ findings in Antarctica: What we do now will determine how quickly Pine Island and Thwaites collapse. A fast transition away from fossil fuels...
Intensifying Winds Could Increase East Antarctica’s Contribution to Sea Level Rise

Intensifying Winds Could Increase East Antarctica’s Contribution to Sea Level Rise

SOURCE: University of Texas News DATE: November 1, 2017 SNIP: Totten Glacier, the largest glacier in East Antarctica, is being melted from below by warm water that reaches the ice when winds over the ocean are strong—a cause for concern because the glacier holds more than 11 feet of sea level rise and acts as a plug that helps lock in the ice of the East Antarctic Ice Sheet. Research led by The University of Texas at Austin has found that wind is responsible for bringing warm water to Totten’s underbelly, causing the glacier to melt from below. This finding helps answer the question of what causes Totten to speed up some years and slow down in others. Climate change is expected to increase the intensity of winds over the Southern Ocean throughout the next century, and the new findings show that Totten Glacier will probably respond to the changing winds. During the next century, winds are expected to intensify and migrate closer to the East Antarctic coast as a result of increased atmospheric greenhouse gas. This study suggests that as winds over the Southern Ocean intensify, so will Totten Glacier’s contribution to global sea level...
British Antarctic research station to shut for second winter as cracks in ice grow

British Antarctic research station to shut for second winter as cracks in ice grow

SOURCE: The Guardian DATE: October 31, 2017 SNIP: A British research station in Antarctica is being shut down for the second winter in a row following concerns over growing cracks in the 150-metre thick ice shelf on which it stands. The Halley VI station, which is parked on the Brunt ice shelf, will be shut down between March and November 2018, with the 14-strong staff who had been gearing up for the winter stint redeployed elsewhere in Antarctica or brought home to the UK. The worries are based on two cracks. The first is an ice chasm that began to show movement northwards in 2012, after more than 30 years of dormancy, and has accelerated over the past seven months. The second, north of the research station, has been dubbed the “Halloween crack” after it appeared in October 2016. It is now estimated to be about 50km in length and growing eastwards, crossing a resupply route for the station. “It has grown a couple of kilometres during the winter period,” said Professor David Vaughan, director of science at the British Antarctic Survey, adding that the crack had also...
‘Scars’ left by icebergs record West Antarctic ice retreat

‘Scars’ left by icebergs record West Antarctic ice retreat

SOURCE: University of Cambridge Research and Washington Post DATE: October 25, 2017 SNIP: Thousands of marks on the Antarctic seafloor, caused by icebergs which broke free from glaciers more than ten thousand years ago, show how part of the Antarctic Ice Sheet retreated rapidly at the end of the last ice age as it balanced precariously on sloping ground and became unstable. Today, as the global climate continues to warm, rapid and sustained retreat may be close to happening again and could trigger runaway ice retreat into the interior of the continent, which in turn would cause sea levels to rise even faster than currently projected. “Ice-cliff collapse has been debated as a theoretical process that might cause West Antarctic Ice Sheet retreat to accelerate in the future,” said co-author Dr Robert Larter, from the British Antarctic Survey. “Our observations confirm that this process is real and that it occurred about 12,000 years ago, resulting in rapid retreat of the ice sheet into Pine Island Bay.” Today, the two glaciers are getting ever closer to the point where they may become unstable, resulting once again in rapid ice...
Warm waters melting Antarctic ice shelves may have appeared for the first time in over 7,000 years

Warm waters melting Antarctic ice shelves may have appeared for the first time in over 7,000 years

SOURCE: The Conversation DATE: October 19, 2017 SNIP: The vast expanse of the Antarctic is a region of the world particularly vulnerable to climate change, where ice loss has the potential to significantly increase sea levels. Now, for possibly the first time in 7,000 years, a phenomenon known as “upwelling” (the upward flow of warmer ocean water to the surface), is thought to have caused recent ice shelf collapse around the continent – and the glacial thinning associated with it. The ocean surrounding Antarctica is extremely cold, but water over 300m deep, Circumpolar Deep Water (CDW), is about 3⁰C above the melting point of ice. Normally, the very cold water above keeps this away from ice shelves. But in some areas, CDW is spilling onto the shallow Antarctic continental shelf, causing the ice to thin. Ice shelf thinning has accelerated in recent decades, but the picture is not the same everywhere. While the east of the Antarctic has shown modest gains in ice thickness, the west has outstripped this with significant ice loss – up to 18% in vulnerable areas like the Amundsen and Bellingshausen...