Events since 1973 of Richter 6.0 or greater on the left. Richter 7.0 on the right. Note the
four distinct clusters among the 6+ events as well as the significant depths of many of the
more westerly events. Of particular interest were two orange events on September 5, 2004
five hours apart: Richter 7.2 at 33.07 136.62 and then a Richter 7.4 at 33.18 137.07. The
two close purple events where almost exactly two years apart (1998 and 2000) and were a
7.1 and a 7.4 at 440 and 394 kilometers deep.