There have been more than 400 tremors recorded in this swarm as of May 11. How unusual is this?

HUMBOLDT COUNTY, CA - A preliminary 3.2 magnitude quake rattled near Rio Dell on Sunday around midday, according to the U.S.

NYE COUNTY, NV - A preliminary 2.3 magnitude quake occurred close to Goldfield on Sunday afternoon, according to the U.S.

The area is "prone to earthquake swarms," officials say.

KERN COUNTY, CA - A 2.1 magnitude quake shook near Johannesburg on Saturday morning, according to the U.S. Geological Survey.

Earthquakes can visibly and permanently crack the ground apart in dramatic and unpredictable surface fault rupture, but new research led by University of Michigan Engineering revealed that soil ...

Southern California and southwest Arizona are on earthquake alert after a swarm shook Imperial County.

RIVERSIDE COUNTY, CA - A preliminary 2.1 magnitude quake shook close to Borrego Springs on Saturday morning, according to the ...

KERN COUNTY, CA - A preliminary 2.1 magnitude quake shook near Johannesburg on Saturday morning, according to the U.S.

A 2.5 magnitude earthquake struck near Why, Arizona, on Friday afternoon.