Earthquake swarm: What caused hundreds of mini-quakes?
| MAMMOTH LAKES, Calif.
A seismologist says a series of more than 600聽earthquakes聽during a 24-hour period 鈥� called an earthquake swarm 鈥� in the Mammoth Lakes region may have been caused by water pressure from area hot springs.
The reports Saturday that U.S. Geological Survey seismologist David Shelly says scientists don't believe the聽earthquake聽swarm聽is connected to any volcanic activity.
Shelly says the quakes may have been triggered as water pressure from area hot springs shifted through the ground surface, stressing tectonic plates.
Shelly says at least 109 of the聽earthquakes聽reported since Thursday were magnitude 2.0 or greater and smaller quakes made up the bulk of the activity.
