The Amery Ice Shelf is one of the largest glacier drainage basins in the world, located on the east coast of Antarctica.Amery is the third largest ice shelf in Antarctica, and is a key drainage channel for the east of the continent.
The National Centre for Polar and Ocean Research (NCPOR) predicts that there would be a 24% increase in the expansion of Ameri Ice Shelf (AIS) boundaries by 2021 and another 24% expansion by 2026 from its 2016 positions.
The prediction made by NCPOR is based on a 16-year-long satellite-based observation that covered an area of 60,000 sq. km across the AIS. Scientists feel that this study would help understand the ongoing changes in the ocean and atmospheric forces better.NCPOR carried out this study based on the satellite data collected from 2001 to 2016. The data were collected during the southern hemisphere summer months of January to March to understand the advancement of AIS extension and the influence of ocean atmospheric forcing in East Antarctica.
The Amery Ice Shelf is one of the largest glacier drainage basins in the world, located on the east coast of Antarctica, at about 70ºS Latitude, 70ºE Longitude. The AIS dynamics and mass balance help in understanding the changes in the global climate scenario.
The extension is a 200-km stretch between Mackenzie Bay and the Sandefjord Bay which is a part of the AIS.
What is an ice shelf?
Ice shelves are permanent floating sheets of ice that connect to a landmass.The floating sheets of ice called ‘ice shelves’ play a multi-faceted role in maintaining the stability of a glacier. Ice shelves connect a glacier to the landmass. The ice sheet mass balance, sea stratification, and bottom water formation are important parameters for the balancing of a glacier. Latent and sensible heat processes do play important roles here.
Most of the world’s ice shelves hug the coast of Antarctica. However, ice shelves can also form wherever ice flows from land into cold ocean waters, including some glaciers in the Northern Hemisphere.
- The Amery Ice Shelf in Antarctica produced its biggest iceberg in more than 50 years, September last year.
- A more than 1,500 sq.km. iceberg broke off Antarctica, but the event was part of a normal cycle and is not related to climate change, scientists say.
- The calved block covers 1,636 sq km in area – a little smaller than Scotland’s Isle of Skye – and is called D28.
- The ‘berg broke near a spot called the “loose tooth” because the ice there is extensively crackedThis is a segment of Amery that has come to be known as “Loose Tooth” because of its resemblance in satellite images to the dentition of a small child.
It becomes clear from the study that the AIS is losing its stability owing to the impact of a downstream giant glacial drainage system over the past 19 years, thereby advancing the ice shelf boundaries due to higher freezing rates than basal melting
NCPOR observations also revealed a critical cooling of the sea surface temperature, resulting in an advancement of the ice shelf by 88 per cent in the past 15 years. These changes would contribute in a major way to climate variability.