Hundreds of Hidden Iceberg Earthquakes Detected at Antarctica's 'Doomsday Glacier'

A new study published in Geophysical Research Letters has identified hundreds of glacial earthquakes at Thwaites Glacier, the West Antarctic ice mass nicknamed the 'Doomsday Glacier' for its potential to raise global sea levels by roughly three meters if it were to collapse. Seismologist Thanh-Son Pham of the Australian National University used regional seismic stations to detect 362 events between 2010 and 2023 that had gone unnoticed because of their low-frequency seismic signatures.

About two-thirds of the detected events, 245 in total, occurred near the glacier's marine edge, where the ice meets the ocean. Most appear to be glacial earthquakes triggered when tall, thin icebergs break away and capsize, slamming back into the parent glacier and sending strong vibrations traveling thousands of kilometers through the Earth's crust.

The largest cluster of activity occurred between 2018 and 2020, a period when Thwaites's floating ice tongue was also accelerating toward the ocean. Researchers say the pattern strengthens the case that the glacier's most unstable section is undergoing faster structural breakdown than previously documented, and they hope continued seismic monitoring can serve as an early warning system for sudden changes in one of the most closely watched glaciers on the planet.