HR: 08:00h
AN: S41C-01    [Abstracts]
TI: 3-D Structure of the Moho Interface beneath South Korea from Regional Seismic Observations
AU: * Gritto, R
EM: rgritto@harris.com
AF: Harris Corporation, 5740 Hollis St., Emeryville, CA 94608, United States
AU: Siegel, J
EM: jsiege01@harris.com
AF: Harris Corporation, 5740 Hollis St., Emeryville, CA 94608, United States
AU: Chan, W C
EM: wchan99@harris.com
AF: Harris Corporation, 1227 S. Patrick Drive, Suite 110A, Satellite Beach, FL 32937, United States
AB: The current project is concerned with the collection and processing of seismic waveform data to perform 3-D tomographic inversions and produce high-resolution 3-D crustal P- and S-wave velocity models for the South Korean peninsula. At present, we have analyzed and archived Korean Meteorological Administration (KMA) waveform data from 2001 through 2006 and mapped of the Moho discontinuity below South Korea. Phase arrival information from both, velocity and accelerometer sensors were collected. The analysis included 226 events throughout the region producing a total of 6,275 phase picks including Pg, Pn, Sg/Lg, and Sn phases. A total of 3,550 P-wave and 2,725 S-wave phases were identified. Using the combination of all available velocity and accelerometer data it was possible to estimate depth locations for 198 KMA events. The hypocenters were subsequently used to derive travel-time distance curves to appraise the quality of the travel-time picks. Static corrections were calculated for each seismic station within the KMA network to remove the effects of local inhomogeneities in the vicinity of each station. After applying static corrections to the observed travel-times, refracted P-wave phases along the Moho boundary were selected from the dataset to estimate the depth and topography of the Moho discontinuity beneath South Korea. In total, 526 Pn phases were collected from the KMA data with hypocentral distances from 130 km to over 650 km. The resulting Moho topography reveals a slightly undulating interface with a large-scale dip from north (31 km) to south (38 km) and a depth range from 32 km in the east to 39 km in the south-west. On a smaller scale, a more pronounced depression is evident in the south- central part of the mapped area, which opens to the south. The presented results are corroborated by other studies which mapped the Moho interface using surface-wave dispersion and receiver-function analysis. The present study is complementary to these earlier works, in that a different method and a different dataset generated comparable results.
DE: 7203 Body waves
DE: 7205 Continental crust (1219)
DE: 7219 Seismic monitoring and test-ban treaty verification
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
SC: Seismology [S]
MN: 2007 Fall Meeting