Suddenly Big Blue Boxes

Seismic activity in California has greatly increased over the past 24 hours as this Cal Tech interactive seismic map shows. It is worth noting that this increase does not relate to a single larger quake but rather from three centers of increased seismic activity with notable moderate mainshocks comprised of the M4.0 that I felt this morning in Paso Robles, CA, and another M4.0 associated with an ongoing earthquake swarm at Long Valley Caldera near Mammoth Lakes, CA, and finally a M5.0 event in the Geysers Geothermal Field in Northern California. It was located about 6 miles northwest of the center of the geothermal field. It occurred at a depth of just about a mile down so this might have generated short ground rupture if it happened along a fault that reaches the surface. This is the largest earthquake ever located here and relates to water injection for purposes of producing steam to generate electricity.