A magnitude 4.8 earthquake occurred about 10 km north of Lake Tahoe at 11:46 AM PST Sunday June 26th at a depth of 12 km. This event follows an M 4.5 event in June of 2004 and a unprecedented very deep, lower crustal, sequence of ~1600 earthquakes in late 2003. The 2003 sequence was associated with a 10 mm uplift of Mt. Rose (high resolution GPS measurements) and was interpreted to be in response to magma injection at 30 km depth. (To know more about the magma injection, download pdf below) In additional, an earthquake of approximately the same size as SundayÆs event, M 4.9, occurred about 8 km north of Incline Village (north shore of Lake Tahoe) in October of 1998 and was also felt throughout the Reno-Tahoe-Carson City area. The figure shows regional earthquake activity since 2000 (earthquakes located by the Nevada Seismological Laboratory û red circles with white centers) with the 2003-2004 activity north of the Lake labeled.     Click the map to enlarge the image

The earthquake was felt widely throughout the Reno and Lake Tahoe region.

Focal Mechanism (JPEG image, 258KB)

The data reported here has been reviewed. For more information, contact the Nevada Seismological Laboratory, (775) 784-4975. The free pamphlet "Earthquakes in Nevada and How to Survive Them," is available on request. The NSL operates a statewide network of seismographic stations and investigates the sizes, frequencies of occurrence, and distribution of earthquakes in the region, and other problems related to seismic risk in Nevada.


2003 Deep Earthquake Swarm

Evidence for Deep Magma Injection Beneath Lake Tahoe, Nevada-California  (PDF format, 413KB)  Smith et al., 2003, Science v 305, 1277-1280.
Supplementary Figures (PDF format, 1.0MB)
Supplementary Text (PDF format, 119KB)