More than 500 earthquakes of magnitude M1.0 in Long Valley Caldera, one of magnitude 3.8. “No immediate hazard,” says USGS
The United States Geological Survey (USGS) has been closely tracking an earthquake swarm in California’s Long Valley Caldera, which started yesterday at around 4AM PDT (September 25, 2014).
Mammoth Mountain East-facing slopes – USGS
According to the USGS website, “the swarm is located 7 miles east of the town of Mammoth Lakes, about a mile north of the airport. From about 4 AM on the September 25th to 11AM on September 26th there have been more than 500 earthquakes of magnitude M1.0 and above, including 8 earthquakes between M3.0 and M3.8, which were felt locally.
“This is one of several earthquake swarms that have occurred in the caldera this year. Despite the several felt earthquakes, this is still rather modest activity compared with the much more energetic swarms occurring in the 1980s and 1990s.
Map showing location of quakes – Courtesy USGS California Volcano Observatory
“We do not see any evidence for anomalous ground deformation associated with the swarm at this time. Part of the Long Valley Caldera, known as the “resurgent dome,” has been uplifting at a rate of about an inch per year since late 2011, and this remains unchanged.
No immediate hazard
“The swarm events pose no immediate hazard. The USGS California Volcano Observatory will continue to closely track this activity and provide updates as appropriate.”
“This one (swarm) is a bit larger and more energetic than we’ve seen in the past few years,” said David Shelly, a seismologist with the U.S. Geological Survey’s California Volcano Observatory who conducts research on earthquake swarms.
The latest magmatic eruptions at Mammoth Mountain took place about 57,000 years ago.
http://volcanoes.usgs.gov/observatories/calvo/
http://www.thecelestialconvergence.com/major-seismic-swarm-precursors-super-eruption-mega-quake-california-hundreds-earthquakes-strike-near-mammoth-lakes-long-valley-caldera-just-hours/
Thanks to Ronald Baker and Bridget Ryan for these links
“Keep an eye on the volcanoes in the western US,” says Ronald.” We will see a major eruption soon. Probably several. Stay vigilant.”