The Napa earthquake reveals hidden fault lines.
The magnitude-6.0 Napa earthquake has created several small, previously unrecognized Napa Valley faults revealed by radar measurements.
The magnitude-6.0 Napa earthquake was centered on the West Napa Fault, which moved about 18 inches (46 centimeters) along a 9.3-mile-long (15 kilometers) length. Amazing!
This largescale movement along the West Napa Fault also created a handful of smaller faults running roughly northwest to southeast, parallel to the West Napa Fault. The mapping was done by UAVSAR (uninhabited aerial vehicle synthetic aperture radar).
While these newly found faults let off the region’s pent-up strain, they may never trigger their own quake. They are probably not big enough to trigger a significant earthquake. But it would be good to know if these new faults are part of a larger fault system.