![]() There are many ways these ice shelves can destabilize. The authors of the study, published in the Nature journal Communications Earth & Environment, used algorithms, climate models and satellite observations to determine that 60% of the peninsula’s calving events – where an iceberg breaks off an ice shelf or glacier – were triggered by atmospheric rivers between 20.Īn image of the Larsen B ice shelf on the Antarctic Peninsula in 2000, before its collapse in 2002. And now, as the climate crisis is projected to warm the Earth further, the biggest remaining ice shelf, Larsen C, is also at risk of total collapse, the study says. These conditions were observed during the collapse of two of the peninsula’s ice shelves – Larsen A and B – in the summers of 19, respectively. Scientists don’t know what role the extreme temperatures may have played in the event, but the heat rushed in through what’s known as an atmospheric river, a long plume of moisture that transports warm air and water vapor from the tropics to other parts of the Earth.Ī new study published Thursday shows that these “rivers in the sky” – which dump rain and snow when they make landfall – are also causing extreme temperatures, surface melt, sea-ice disintegration and large ocean swells which are destabilizing ice shelves on the Antarctic Peninsula, a long, spindly mountain chain that points northwards to the tip of South America. But if the ice shelf does begin to retreat or collapse, history tells us it is very possible that its glaciers will flow faster - making yet more sea level rise inevitable.When temperatures in Antarctica soared to 38 degrees Celsius above normal – around 70 Fahrenheit – in March, a teetering ice shelf the size of Los Angeles collapsed. ![]() We can’t yet predict the full consequences of the new iceberg calving from Larsen C. It seems the Fleming Glacier has a long way to go before it will return to a new stable state (in which snowfall feeding the glacier equals the ice flowing into the oceans).įifty years after the Wordie Ice Shelf began to collapse, the major feeding glaciers continue to thin and flow faster than before. Other research has suggested this lift could have acted to slow the glacier’s retreat, but it’s clear that the bedrock deformation has not stopped the ice movement speeding up. The weight of this ice moving off the land and into the ocean has caused the bedrock beneath the glaciers to lift by more than 50mm. We estimate the total glacier ice volume lost from all glaciers that feed the Wordie is 179 cubic kilometres since 1966, or 319 times the volume of Sydney Harbour. These changes all point to ice shelf collapse as the cause. This is the largest speed change in recent years of any glacier in Antarctica. Ice flow speeds have also increased by more than 400m per year at the front since 2008. Ice thinning rate of the Fleming Glacier region during (a) 2002-2008 and (b) 2008-2015. Those glaciers continue to flow faster to this day. Almost immediately afterwards, the glaciers feeding into it sped up by two to six times. ![]() Over the course of just six weeks in 2002 the entire ice shelf splintered into dozens of icebergs. The most dramatic ice shelf collapse observed so far is that of Larsen C’s neighbour to the north - the imaginatively named Larsen B. Using aerial and satellite images, scientists have been able to track very similar ice shelves in the past, some of which have been seen to retreat and collapse. While the prediction that Larsen C could become unstable is based partly on physics, it is also based on observations. This has a much larger effect on sea level than iceberg calving does. Removal of the ice shelf causes glaciers to flow faster, increasing the rate at which ice moves from the land into the sea. Glaciers flow from land towards the sea, and their ice is eventually absorbed into the ice shelf. Ice shelves essentially act as corks in a bottle. An iceberg about the size of Delaware has split off from Antarctica - scientists wonder: what happens next? /pl0bOXTAMcâ NASA ICE July 12, 2017
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