This process was evident on both Larsen A and B, and a few times on the Wilkins Ice Shelf. What causes disintegration of an ice shelf?ĭisintegration of an ice shelf is a specific term for the water-induced, extremely rapid calving process. The largest waves can buckle and bend an ice shelf, increasing instability and possibly contributing to a collapse. As sea ice decreases, more waves buffet the ice shelves. Sea ice provides a layer of protection between an ice shelf and the surrounding ocean, muting the power of large waves and storms. Recent research suggests that waning sea ice surrounding the Antarctic Peninsula and the Arctic ice shelves in Canada might also have contributed to the recent collapses. However, high temperatures alone do not fully explain rapid ice shelf collapse. Scientists have observed both processes in all the ice shelves that have rapidly retreated in recent years. In a separate process, warmer water melts the ice shelf from below, thinning it and making it more vulnerable to cracking. As the water trickles down through small cracks in the ice shelf, it deepens, erodes, and expands those cracks. Warm air melts the ice shelf surface, forming ponds of meltwater. Scientists attributed rapid ice shelf collapse to warmer air and water temperatures, as well as increased melt on the ice shelf surface. The peninsula has warmed 3 degrees Celsius (5.4 degrees Fahrenheit) since 1950, making it one of the fastest-warming places on Earth. The Antarctic Peninsula juts north towards South America into warmer waters. Most of the rapidly retreating ice shelves in Antarctica are located on the Antarctic Peninsula. Credit: think the increase in ice shelf collapses in both the Arctic and Antarctica are related to climate change. As the ice tongues have retreated, the reduced back pressure against the glacier has allowed these glaciers to accelerate significantly.īy 2006, the Jakobshavn Glacier had retreated to where its two main tributaries joined, leading to two fast-flowing outlets for its ice where there had previously been just one.Ī grounded iceberg rests in the Errera Channel just off of Cuverville Island on the western side of the Antarctic Peninsula. In recent years, calving of the largest ice tongues in Greenland (in particular, Jakobshavn, Helheim, and Kangerdlugssuaq) has accelerated, probably because of warmer air and ocean temperatures. These denizens of the ocean are now tracked by the National Ice Center in the United States, along with other organizations. The Petermann Glacier in northwestern Greenland also shed a large ice island in August 2010. Jakobshavn likely shed the iceberg responsible for the sinking of the Titanic in 1912. Calving of the large glacier, Jakobshavn, on the east coast of Greenland, is responsible for the majority of icebergs reaching Atlantic shipping and fishing areas off Newfoundland. These smaller, steep-sided icebergs sometimes drift south, reaching North Atlantic shipping lanes. In Greenland, floating ice tongues downstream from large outlet glaciers are broken up by crevasses. Huge icebergs calve off of Jakobshavn Isbrae Glacier in Greenland, and then drift towards the Atlantic. However, they eventually are caught up in north-drifting currents, where they melt and break apart further. The icebergs drift generally westward around the continent, and as long as they remain in the cold, near-coastline water, they can survive decades or more. On a stable ice shelf, calving is a near-cyclical, repetitive process producing large icebergs every few decades. Ice shelves and calvingĪt their seaward edge, ice shelves periodically calve, or break off, chunks of ice called icebergs-some have been the size of a small US state or European country. Together, an ice shelf and the glaciers feeding it can form a stable system, with the forces of outflow and back pressure nearly balanced. This give-and-take maintains a kind of dynamic stability if climate conditions are relatively stable. Ice shelves grow when they gain ice from land and occasionally shrink when icebergs calve off their edges. Credit: Ronja Reese/ImaggeoĪlong protected coastlines, the resulting ice shelves can survive for thousands of years, supported by the rock of peninsulas and islands. This view of the Brunt Ice Shelf in Antarctica demonstrates the thickness of ice shelves, which range from about 50 to 600 meters (160 to 2000 feet). Exchange for Observations and Local Knowledge of the Arctic (ELOKA).NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).Greenland Today & Antarctic Ice Sheet Today.
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