Scientists at the Nevada Seismological Laboratory and Nevada Bureau of Mines and Geology at the University of Nevada, Reno, the California Institute of Technology, and the Harvard-Smithsonian Center for Astrophysics published an article in Science Magazine analyzing a recent earthquake sequence near Lake Tahoe. According to their study, the sequence illuminates a 7x5-kilometer planar feature in the lower-crust (depths of 27-31 km), which is unusually deep for earthquakes in the Sierra Nevada. The swarm in late 2003 coincided with an uplift of approximately 10 mm observed at the Slide Mountain GPS site. The researchers interpret the earthquake sequence and uplift as a possible indication of magma injection at great depth.
The largest recent earthquake in this area was the M6.0 September 12, 1966 Truckee earthquake.
The article is available in the August 5th edition.