The time history of great earthquakes is shown in the left panel, whereas the right panel shows the rupture areas of the past 100 years of earthquakes. Notice the apparent migration of large quakes toward the M=5.7 over the past 80 years (grey arrow in left panel); this could be a random artifact, or it could be caused by Coulomb stress transfer (Lin and Stein, 2004). Today’s quake struck in a gap in historical rupture zones; this gap could be permanent, but that is not assured. The figure annotated from Villegas-Lanza et al. (2016).