Deep earthquakes and the thermal assimilation of subducting lithosphere

Two problematic aspects of deep seismic zones are investigated: the maximum depth (about 700 km) of seismic activity and the relative maximum in seismic energy release in the 500‐700 km depth range. It is shown that both features can be accounted for by a model based on thermal assimilation. This implies that no barrier is required at a depth of 650‐700 km to explain the observations.