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Antarctic glaciers slip faster towards the ocean due to surface melting



  Drygalski Glacier Antarctic Peninsula

The surface meltwater flowing through the ice and under the Antarctic glaciers leads to new research on sudden and rapid accelerations of the flow towards the sea. It is the first time that scientists have discovered that melting on the surface affects the flow of Antarctic glaciers.

  • A study shows for the first time a direct correlation between surface smelting and short bursts of glacier acceleration in the Antarctic
  • . The glaciers of the Antarctic Peninsula are up to 100 percent faster than the average.
  • Scientists call for these results to be included in sea-level rise predictions

    This is the first time scientists have discovered that surface smelting affects the flow of Antarctic glaciers.

    Using images and data from satellites and regional climate models, scientists from The University of Sheffield have found that some glaciers move 100 percent faster than the average (up to 400 meters per year) due to meltwater Period of several days several times a year.

    Glaciers move by gravity over the ice's inner deformation and downslides – sliding over the underlying soil with lubricated liquid water.

    The new study published today (September 20, 2019) in Nature Communications shows that acceleration of glacial movements on the Antarctic Peninsula coincides with peaks in snowmelt. This association occurs because surface melt water enters the ice bed and lubricates the glacial flow. Scientists predict that with rising temperatures in the Antarctic, the surface melts more frequently and over a wider area. This is an important factor in determining the speed at which glaciers move towards the sea.

     Crane Glacier Antarctic Peninsula

    Ultimately, they predict that the glaciers on the Antarctic Peninsula will behave as they do in Greenland today and in Alaska, where meltwater determines the size and timing of the island's fluctuations Glacier river over seasons and years controlled.

    The impact of such a strong shift of the Antarctic glacier melt on the ice flow has not yet been included in the models used to predict the future mass balance of the Antarctic ice sheet and its contribution to sea-level rise.

    Dr. Jeremy Ely, Independent Research Fellow at the Department of Geography at the University of Sheffield and author of the study, said, "Our research shows for the first time that surface meltwater gets under Laciers on the Antarctic Peninsula, which lead to short bursts that are 100% faster than glide normally towards the sea.

    "As atmospheric temperatures continue to rise, we expect more surface meltwater than ever before, so that such behavior can occur more frequently in the Antarctic.

    "It is crucial that this factor be taken into account in models of future sea-level rise so that we can prepare for a world with fewer and smaller glaciers." The polar and alpine change at the University of Sheffield said: "The direct relationship between surface melt and glacier flow rates is well documented in other regions of the world, but this is the first time that we have observed this coupling throughout the Antarctic. [19659008] "Given the expected increase in atmospheric temperatures and thus surface melting rates in the Antarctic, this discovery could have a significant impact on future sea-level rise rates."

    Episode: "Fast Acceleration of the Antarctic Peninsula's Outlet Glaciers by Surface Melting" by Peter A. Tuckett, Jeremy C. Ely, Andrew J. Sole, Stephen J. Livingstone, Benjamin J. Davison, J. Melchior van Wessem, and Joshua Howard , September 20, 2019, Nature Communications .
    DOI: 10.1038 / s41467-019-12039-2

    Images: Google Earth


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