U.S. seismic hazard zones awaken: Long Valley super-volcano earthquake swarm notice

August 24, 2011 – MAMMOTH LAKES, Calif. – Long Valley Caldera – While the East Coast recovers from earthquake jitters, small quakes have been rocking California. A minor jolt struck the San Francisco Bay area Wednesday at 9:57 a.m., just hours after a similar temblor hit the same spot late Tuesday night. The U.S. Geological Survey says both magnitude- 3.6 quakes were centered about six miles southeast of Oakland along the Hayward fault, a major Northern California fault zone. The Sierra Nevada high country was also rattled by an earthquake early Wednesday. The USGS says a magnitude- 4.4 quake hit at 4:59 a.m. about nine miles southeast of Mammoth Lakes. A Mono County sheriff’s dispatcher says authorities have had no reports of damage. A magnitude-5.8 quake jolted much of the eastern United States on Tuesday. –Sac Bee  The map on the left is the blast radius of any potential large-scale eruption at the Long Valley caldera.

contribution Rosem