Structure of the Korean Peninsula from Waveform Travel-Time Analysis
Abstract
Seismic waveform data of the Korean Meteorological Administration (KMA) have been analyzed to perform 3-D tomographic travel-time inversions to produce high-resolution 3-D crustal P- and S-wave velocity models for the South Korean peninsula. In a first step, waveform data from 2001 through May 2008 have been analyzed to map the Moho discontinuity below South Korea using refracted Pn travel times. Phase-arrival information from both velocity and accelerometer sensors was collected. The analysis included 270 events throughout the region producing 8,860 phase picks of Pg, Pn, Sg/Lg, and Sn phases. A total of 5,090 P-wave and 3,770 S-wave phases were identified. Using the combination of all available velocity and accelerometer data from the 119 KMA stations, it was possible to estimate depth locations for 226 KMA events. The hypocenters were subsequently used to derive travel-time distance curves based on 1-D velocity models to appraise the quality of the travel-time picks. The analysis produced, respectively, crustal P- and S-wave velocities of 6.13 km/s and 3.57 km/s and upper mantle velocities of 8.02 km/s and 4.48 km/s. The travel-time distance curves were used to determine static corrections for all station locations. After applying static corrections to all 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. The resulting Moho topography reveals a relatively flat interface with depth variations from 28 to 34 km. The shallowest parts are below the Yellow Sea and below the Sea of Japan, while the deepest structure is located below the Yeongnam Massif. Joint inversion for hypocenters and velocity structure was performed to derive 3-D P- and S-wave velocity models for the crust.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2008
- Accession Number
- ADA516110
Entities
People
- Jacob E. Siegel
- Roland Gritto
- Winston W. Chan
Organizations
- Array Information Technology (United States)