Volcano Update from Archive

Friday, April 29, 2011 4:08 PM PDT (Friday, April 29, 2011 2308 UTC)

Long Valley Volcanic Center Volcano
37°42' N 118°52'12" W, Summit Elevation 7231 ft (2204 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Eleven small earthquakes between magnitude M=1.0 and M=2.4 occurred in the Mammoth Lakes-Long Valley caldera region since the last update on April 22, 2011. Most of these events occurred in the Sierra Nevada south of the caldera, with only two earthquakes detected inside the caldera (south moat; M=1.5 and M=2.2) A cluster of six earthquakes on the east shore of Mono Lake were also detected, the largest of which had a magnitude of M=2.0. Elsewhere in the region, just over the border to the northeast between Mono Lake and the town of Hawthorne, Nevada, the energetic swarm of earthquakes that started on Sunday, April 10 continues. Over twenty-nine earthquakes have been detected in the magnitude M=3.0 range and ten between magnitude M=4.0 and M=4.6. Mild shaking from the larger of these events may have been felt in Bridgeport, CA. The Nevada swarm is non-volcanic in origin. More information can be found at the University of Nevada Seismological Laboratory website at http://www.seismo.unr.edu/.