Antarctica Doomsday Glacier Rattled by Hundreds of Iceberg Earthquakes

"Glacial earthquakes are a special type of earthquake generated in cold, icy regions. First discovered in the northern hemisphere more than 20 years ago, these quakes occur when huge chunks of ice fall from glaciers into the sea. Until now, only a very few have been found in the Antarctic. In a new study published in Geophysical Research Letters, I present evidence for hundreds of these quakes in Antarctica between 2010 and 2023, mostly at the ocean end of the Thwaites Glacier the so-called Doomsday Glacier that could send sea levels rising rapidly if it were to collapse."

"A glacial earthquake is created when tall, thin icebergs fall off the end of a glacier into the ocean. When these icebergs capsize, they clash violently with the mother glacier. The clash generates strong mechanical ground vibrations, or seismic waves, that propagate thousands of kilometers from the origin. What makes glacial earthquakes unique is that they do not generate any high-frequency seismic waves. These waves play a vital role in the detection and location of typical seismic sources, such as earthquakes, volcanoes and nuclear explosions. Due to this difference, glacial earthquakes were only discovered relatively recently, despite other seismic sources having been documented routinely for several decades."

Hundreds of glacial earthquakes occurred in Antarctica from 2010 to 2023, predominantly at the ocean terminus of Thwaites Glacier. Tall, thin icebergs calve and capsize, colliding with the parent glacier and generating low-frequency seismic waves that can travel thousands of kilometers. These events lack high-frequency seismic energy, which complicates detection and localization by conventional seismic methods. Most previously detected glacial earthquakes were recorded near Greenland glacier termini and can be relatively large in magnitude. The concentration of events at Thwaites Glacier raises concerns because collapse of that glacier could contribute substantially to sea level rise.

Read at theconversation.com