Red dots represent events occuring in the past month. Green dots represent events occuring less than a year ago, but more than a month ago. Circles represent older events. Triangles represent PNSN seismic stations.
Black squares represent major cities.
Black stars indicate volcanoes. Time-Depth Plot Graph showing relationship between time and depth of earthquakes near CraterLake. In this graph, sea level is equal to 0 km depth.