Northern California’s coast keeps you on alert, even on quiet days. Offshore, three tectonic plates meet near Humboldt County ...

What appears to be three tectonic plates in a map may act like five pieces that move underground. Northern California ...

A hidden shard of ancient crust has been detected where California’s San Andreas system collides with the Cascadia subduction zone, reshaping how I understand the tectonic engine of the West Coast.

Remote sections along California’s massive San Andreas Fault, where large earthquakes regularly occur, may be primed to shake again any day now, according to a new study. The area around Parkfield in ...

An earthquake struck near the High Desert community of Pearblossom, and along the San Andreas Fault. The magnitude 3.3 quake struck at 10:49 p.m. on Monday, Sept. 8, four miles south of Pearblossom in ...

The West Coast of North America is a geologically tumultuous zone where tectonic plates collide, subducting under and scraping past one another. Over the eons, this activity has regularly caused major ...

By tracking swarms of very small earthquakes, seismologists are getting a new picture of the complex region where the San ...

Last Monday, April 14, an earthquake caught many people’s attention in Southern California. It was centered near the town of Julian about 35 miles inland from San Diego and triggered the USGS ...