![]() Part of the reason is that satellite imagery has been challenging to interpret. Although satellite altimeters measure the thinning process by recording the changing height of the ice, until this study, there hasn’t been a comprehensive assessment of how climate change might be affecting calving around the continent. However, in recent decades, the warming ocean has been destabilizing Antarctica’s ice shelves by melting them from below, making them thinner and weaker. The missions that supplied data are listed at the bottom. Ice height diminishes (red) as the ice sheet melts by contact with ocean water it rises (blue) where accumulation exceeds melting. When ice shelves are stable, they have a natural cycle of calving and replenishment that maintains their size fairly consistently over the long term.Ĭhanges in elevation of the Antarctic ice sheet from 1985 to 2021 are shown. Ice shelves act like buttresses to glaciers, keeping the ice from simply sliding into the ocean. Most Antarctic glaciers flow to the ocean, where they end in floating ice shelves that are up to 2 miles (3 kilometers) thick and 500 miles (800 kilometers) across. “And when ice shelves dwindle and weaken, the continent’s massive glaciers tend to speed up and increase the rate of global sea level rise.” “Antarctica is crumbling at its edges,” says JPL scientist Chad Greene, lead author of the calving study. Combined, the complementary reports provide the most complete view yet of how the frozen continent is changing. The other study, published recently in the journal Earth System Science Data, shows in unprecedented detail how the thinning of Antarctic ice as ocean water melts it has spread from the continent’s outward edges into its interior, almost doubling in the western parts of the ice sheet over the past decade. Ice loss from calving has weakened the ice shelves, allowing Antarctic glaciers to flow more rapidly to the ocean and accelerating the rate of global sea level rise. ![]() This surprising finding doubles previous estimates of ice loss from the Antarctic’s floating ice shelves since 1997, from 6 trillion to 12 trillion metric tons. The scientists found that the edge of the ice sheet has been shedding icebergs faster than the ice can be replaced. They are set to be collected by aircraft around February 6, according to the BAS, a world leader in environmental research in the region.One study, published recently in the journal Nature, maps how iceberg calving – the breaking off of ice from a glacier front – has changed the Antarctic coastline over the last 25 years. “Our science and operational teams continue to monitor the ice shelf in real-time to ensure it is safe, and to maintain the delivery of the science we undertake at Halley,” added Hodgson. They maintain the power supplies and facilities that keep scientific experiments operating remotely through the winter, when it is dark for 24 hours and the temperature falls below minus 50 degrees Celsius (minus 58 degrees Fahrenheit). Since then, staff have been deployed only during the Antarctic summer between November and March, with 21 researchers currently on-site. ![]() The mobile research base was relocated to the station about 20km (12.4 miles) further inland in 2016 as cracks in the ice threatened to cut it off. The iceberg, which has yet to be named by the US National Ice Center, is now expected to drift off with the current along the Antarctic coast like previous massive icebergs.īritain’s Halley VI Research Station monitors the state of the vast floating ice shelf daily but is unaffected by the latest rupture. In the years since, the gap widened until the chunk of ice broke away.Ī similar spectacular separation, involving a 1,270sq km (490 square miles) iceberg, occurred about a year ago. The fissure in the ice sheet, which researchers named Chasm-1, was discovered years ago. Scientists refer to “calving” when chunks of ice break off at the terminus, or end, of a glacier. “This calving event has been expected and is part of the natural behaviour of the Brunt Ice Shelf,” said BAS glaciologist Dominic Hodgson. The British Antarctic Survey (BAS) said the formation of the new iceberg was not due to climate change – which is accelerating the loss of sea ice in the Arctic and parts of Antarctica – but to a natural process called “calving”. The iceberg, measuring 1,550sq km (598 square miles), detached from the 150-metre (492-foot)-thick Brunt Ice Shelf a decade after scientists first spotted massive cracks in the shelf. A huge iceberg nearly the size of Greater London has broken off the Antarctic ice shelf near a research station, the second such split in two years, researchers said. ![]()
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