News & activity updates
Long Valley caldera (California, USA): small earthquake swarm east of Mammoth Mountain
Tuesday Feb 11, 2014 20:10 PM | BY: T
Location of recent earthquakes near Mammoth Mountain (CA)
An small earthquake swarm at shallow depths (around 5 km) occurred east of Mammoth Mountain during the past week. The largest quake was a magnitude 3.0 event on 5 Feb.
Number of earthquakes in the Long Valley caldera over the 30 days, showing the recent swarm (USGS)
This latest (of many in the past years) seismic swarm is weak in terms of number and energy of earthquakes compared to long-term averages of seismic activity at the Long Valley caldera, an active volcanic system that is capable to erupt (probably not in a near future, though) and is being closely monitored by very experienced staff from USGS.
It could be related to a small intrusion of magma, but is unlikely to be a precursor of a new eruption in any near future. USGS has not changed the status code of the volcanic system (at green=normal).
Sunday, Feb 03, 2013
Small earthquakes continue beneath and (mostly) immediately to the SE of Mammoth Mountain in the Sierra Nevada range. [more]
Tuesday, Jan 29, 2013
Another small earthquake swarm occurred under the (dormant) volcano during 28-29 Jan. Numerous tiny quakes were registered at shallow depths (mostly 1-5 km). [more]
Tuesday, Jan 22, 2013
Tiny earthquakes (less than mag 1) and some deep low-frequency events continue to occur at normal background levels under Mammoth Mountain. [more]
Monday, Jan 21, 2013
A small earthquake swarm occurred at Mammoth Mountain during 14-20 Jan and seems to have ended. [more]
Sunday, Jan 06, 2013
A small seismic swarm occurred between 4-5 January with quakes at depth of 12-15 km. [more]