| Long Valley has been one of the most seismically active regions in California for the last 25 years. In addition to this seismicity, Long Valley is an active volcanic region. Ash from previous eruptions has fallen over an area including twelve states, extending as far east as Kansas. This seismic and volcanic activity has resulted in the region being densely populated with scientific instruments. These features make Long Valley an ideal location for a tomographic study. This study focuses on magma chamber location beneath the Long Valley Caldera. Using precisely relocated earthquake hypocenters from hypoDD (Waldhauser, 2001) I used a double-difference tomography program tomoDD (Zhang and Thurber, Aug. 2003) to determine the velocity structure beneath Long Valley Caldera. I then used the velocity data to determine the locations of the magma chamber and CO2 reservoir beneath the caldera from 1980 to mid-1997, 1997 to 1998, and 1999 to 2006. |
