Fingerprinting Slow Earthquakes And How They Relate To The Big One

an anomalous layer at the top of a subducting plate coincides with the locations of slow earthquakes and non-volcanic tremors... The presence of such a layer in similar settings elsewhere could point to other regions of slow quakes. Slow earthquakes, also called silent earthquakes, take days, weeks, or even months to release pent-up energy instead of seconds or minutes as in normal earthquakes....