Fig. 8. (a) Epicenters of 407 M > 5 earthquakes from 1900 to 2012 juxtaposed on the interstation-distance contour map. For a given station location, the interstation distance is determined by averaging the distance to the nearest three stations. (b) Map of blind-zone radius for California. Yellow and orange colors correspond to regions with small blind zones and red and dark-red colors correspond to regions with large blind zones.