Earthquakes

Magnitude 5+ Earthquakes – Global

5.4 Earthquake hits the Mid-Indian ridge.

5.3 Earthquake hits Pakistan.

5.2 Earthquake hits El Salvador.

5.2 Earthquake hits off the coast of Hokkaido, Japan.

5.0 Earthquake hits the Mid-Indian ridge.

Record-Breaking 408 Earthquakes Hit Bay Area City

A whopping 408 earthquakes have hit San Ramon, California, in the past two weeks, including 11 in one 24-hour stretch.

This record-breaking earthquake swarm is nothing to fear, however, according to the U.S. Geological Survey (USGS). Periods of tectonic unrest are common in the area and probably don't presage a larger quake, the USGS said.

Most of the quakes affecting this Bay Area city are tiny. The one that kicked off the swarm at 8:50 a.m. Pacific Time on Oct. 13 was a mere magnitude 0.8. People don't usually feel earthquakes until they reach a magnitude of 2.5; quakes between magnitude 2.5 and 5.4 can be felt but rarely cause much damage.

The quakes are hitting on the north end of the Pleasanton Fault in the Calaveras Fault zone, according to the USGS. Swarms of small earthquakes are common in this fault system. In fact, in 1990, a swarm of 351 earthquakes struck over a 42-day period. The largest quake in that swarm was a magnitude 4.2, a level unlikely to cause serious damage.