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.