East Antarctic Ice Sheet has history of instability

https://www.nasa.gov/news/releases/latest/index.html

The East Antarctic Ice Sheet locks away enough water to raise sea level an estimated 53 meters (174 feet), more than any other ice sheet on the planet. It’s also thought to be among the most stable, not gaining or losing mass even as ice sheets in West Antarctica and Greenland shrink.
Source: Psys.org
East Antarctic Ice Sheet has history of instability
Psys.org