Most earthquakes occur in the upper 20km of the Earth’s crust,
where the rocks are cold, brittle, and elastic, able to build up the
tectonic stresses released in sudden earthquake events. Below
this depth, the lower crust is hotter and rocks there typically
deform plastically and steadily, rarely accumulating enough
stress for large earthquakes.
Despite this, some of the largest earthquakes can initiate in the lower crust, and improving our understanding of these deeper and potentially devastating earthquakes is the aim of a NERC-funded University of Plymouth based project involving Luca Menegon, Lucy Campbell and Iain Stewart.