Map showing the revised location of the M6.2 Petrolia earthquake on 12/20/2021

Map showing the revised location of the M6.2 earthquake (blue circle) that occurred on 12/20/2021.  The magnitude 5.7 and 4.0 foreshocks (dark grey) are located offshore along the Mendocino fault.  Aftershock of this sequence are shown in yellow and historical earthquakes of magnitude 5 and greater in the last 40 years are shown in light grey.