Dramatic Rise Detected in West Antarctica's Coastal Ice Sheet

Understanding how the ice sheet grows and shrinks over time enhances scientists' understanding of the processes that impact global sea levels. A new research has revealed that annual snow accumulation on West Antarctica's coastal ice sheet increased 30% during the 20th century.

The researchers used ice cores to estimate annual snow accumulation from 1712 to 2010 along West Antarctica's coast. They found that until 1899, annual snow accumulation remained steady, averaging 33 and 40 centimeters of water, or melted snow, each year at two locations. Annual snow accumulation was found to increase in the early 20th century, rising 30% between 1900 and 2010.

‘The annual snow accumulation on West Antarctica's coastal ice sheet increased 30% during the 20th century. Researchers attributed this in part to an intensification of a regional low pressure system and more storms in the region.’

In the past 30 years of the study, the ice sheet gained nearly five meters more water than it did during the first 30 years of the studied time period. Lead author of the study Elizabeth Thomas, paleoclimatologist with the British Antarctic Survey in Cambridge said, "Since the record is 300 years long, we can see that the amount of snow that has been accumulating in this region since the 1990s is the highest we have seen in the last 300 years. The 20th century increases look unusual."

Thomas attributed this higher annual snow accumulation over the last 30 years in part to an intensification of a regional low pressure system and more storms in the region. She said, "These storms could increase with climate change, possibly leading to further increases in snow accumulation. Snow accumulation builds up the ice sheet, but the extra flakes have not acted as a life raft for West Antarctica's ice sheet, which previous research has found is rapidly thinning as the climate warms. The size of the ice sheet depends on how much new snow accumulates and how much of the existing ice melts."

The findings appeared in Geophysical Research Letters.

Source: IANS