Glacial Earthquakes

Glacial earthquakes are a newly discovered class of seismic events. Most of these events occur along the coasts of Greenland, where large outlet glaciers reach the ocean. Glacial earthquakes show a strong seasonality, with most events occurring during the late summer. The rate of glacial-earthquake occurrence increased between 2000 and 2005. Recent observations establish a strong correlation between the seismic signals of glacial earthquakes and large ice calving events in which icebergs of cubic-kilometer scale collapse against the face of the glacier. A sudden change in glacier speed results from these glacial-earthquake calving events. Glacial earthquakes also occur in Antarctica but are less well studied. They exhibit several characteristics similar to glacial earthquakes in Greenland.

Calving Earthquake Mechanism