Expansion of the Amery Ice Shelf | 04 Jun 2020
Why in News
The National Centre for Polar and Ocean Research (NCPOR) has predicted an increase in the expansion of Amery Ice Shelf (AIS) boundaries from its 2016 positions.
- The AIS is one of the largest glacier drainage basins in the world, located on the east coast of Antarctica.
- The AIS dynamics and mass balance help in understanding the changes in the global climate scenario.
- The prediction made by NCPOR is expected to help to understand the ongoing changes in the ocean and atmospheric forces better.
- The floating sheets of ice are called ‘ice shelves’. It plays a multi-faceted role in maintaining the stability of a glacier.
- The ice sheet mass balance, sea stratification, and bottom water formation are important parameters for the balancing of a glacier. Ice shelves connect a glacier to the landmass.
- The ice sheet mass balance of a glacier is the net balance between the mass gained by snow deposition, and the loss of mass by melting.
- Sea stratification takes place when water masses with different properties - salinity, oxygenation, density, temperature - form layers that act as barriers to water mixing.
- The deep-ocean bottom water is formed by the cooling and sinking of surface water at high latitudes.
- The predictions are based on a 16-year-long satellite-based observation that covered an area of 60,000 sq. km across the AIS.
- The study intends to analyze AIS extension and the influence of ocean atmospheric forcing in East Antarctica.
- Expansion of AIS:
- It has been predicted that there would be a 24% increase in the expansion of AIS boundaries by 2021 and another 24% expansion by 2026 from its 2016 positions.
- The study has also observed a spatio-temporal change in the ice shelf as reflected by the extension of the Prydz, Mackenzie and the Sandefjord Bays which forms a part of the AIS.
- In the background of the global warming scenario, the study reveals about the advancement in the predicted ice shelf extent, the future dynamism of ocean heat fluctuation and Antarctic Amery ice shelf mass shifting-extent.
- The study has also observed that the critical cooling of the Sea Surface Temperature (SST) is resulting in an advancement of the ice shelf by 88% in the past 15 years. These changes would contribute in a major way to climate variability.