Scientists have solved the mystery of how earthquakes can occur 420 miles deep inside Earth, where extreme pressure and heat ...

1. Figure 1: Map of the northern Cascadia subduction zone showing the distribution of earthquakes in the subducting Juan de Fuca plate and the locations of seismic cross-sections. Green dashed line ...

because it is impossible that there were subduction zones nearby in the recent geological history. Seismic cross section through the Pacific showing a cold anomaly (in blue) beneath much of the plate ...