Sixty percent of the world’s freshwater is stored in Antarctica’s ice sheets. This equates to thirty million cubic kilometers of ice. If all of this ice was to melt, the seas would rise by 58 meters.
Most melting/ice loss in Antarctica occurs through ocean-driven melting of ice shelves and ice calving. This results in an acceleration of ice streams on land and a greater discharge of ice into the ocean, where it gets lost to melting/calving.
The ice sheet in Antarctica is not evenly distributed. In the west, large parts of the ice sheet lie below sea level, down to a depth of 2,500 metres. This makes it very exposed to ocean warming. In contrast, a large part of the ice sheet in the east sits directly on land, above sea level, meaning it is less sensitive to the ocean’s influence.
“From the evidence we presented in our study, we concluded that the East Antarctic ice sheet in Queen Maud Land also melted rapidly along its margins between 9,000 to 5,000 years ago, in a period we call the mid-Holocene. At this time, many parts of the world experienced warmer-than-present summers,” says professor Irina Rogozhina
“Although this kind of response by the East Antarctic ice sheet to the warmth during the Holocene is not completely unexpected, it is still difficult and worrisome to believe that the sluggish East Antarctic ice sheet can change so rapidly,” she said.
The researchers also think they know the reason the ice sheet sector in East Antarctica thinned so much immediately after the end of the last ice age.
“We believe that the ice sheet became less stable due to higher, regional sea levels and warmer water rising from the ocean depths in the polar regions, penetrating under the ice margins and melting them from below. This leads to the break-up of large icebergs and accelerates the movement of ice from the land to the ocean, which in turn thins the inland section of the ice sheet. The process is similar to when a house on a hill slope loses its supporting foundation and starts sliding downhill,” Rogozhina said.
In brief, the less stable, rapidly flowing parts of the ice sheet in East Antarctica, broke up more easily, which in tern led to the ice sheet becoming much thinner within a relatively short time, geologically speaking, or a few hundreds to thousands of years.
https://maritime-executive.com/editorials/the-ice-in-east-antarctica-has-melted-before