California has some of the most notorious and closely analyzed fault lines of any state in the United States. It should come as no surprise, then, that it’s one of the Golden State’s signature fault systems that bore responsibility for Sunday’s early morning 6.0-magnitude quake.
Researchers at the United States Geological Survey produced a detailed description of the seismic origin – and history – of the region in Napa Valley where the earthquake occurred. According to the USGS report, the earthquake “lies within a 70-km-wide (44 miles) set of major faults of the San Andreas Fault system,” and within that body, the epicenter nestled between “the well-known West Napa Fault, and the less well-known Carneros-Franklin Faults.”
For those inspired to do some heady geological reading, you can check out the full report here:
How does Sunday’s 6.0 magnitude earthquake – the largest in the state since the 1989 Loma Prieta quake – stack up to past quakes in this region? The largest in recorded history, according to the USGS, was an 1898 Mare Island event that registered at a magnitude of 6.3.