An increase in the expansion of Amery Ice Shelf (AIS) predicted

An increase in the expansion of Amery Ice Shelf (AIS) predicted

Part of: GS-Prelims and GS-III – Climate change

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.

Key takeaways 

• The predictions are based on a 16-year-long satellite-based observation that covered an area of 60,000 sq. km across the 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 (belonging to both space and time) 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.
• 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.

Important value additions 

Ice Shelves

• The floating sheets of ice are called ‘ice shelves’. 
• It plays a major role in maintaining the stability of a glacier.
• Ice shelves connect a glacier to the landmass.
• Important parameters for the balancing of a glacier:
  • Ice sheet mass balance
  • Sea stratification 
  • Bottom water formation  
• The ice sheet mass balance – Net balance between the mass gained by snow deposition and the loss of mass by melting.
• Sea stratification – When water masses with different properties 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.