HR: 0800h
AN: T41A-1289    [Abstracts]
TI: Preliminary Results of the Second Seismic Refraction Experiment in Korea
AU: Baag, C
EM: baagce@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742 Korea, Republic of
AU: * Sheen, D
EM: sheendh@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742 Korea, Republic of
AU: Lee, J
EM: jung@knu.ac.kr
AF: Department of Geology, Kyungpook National University, Daegu, 702-701 Korea, Republic of
AU: Moon, W M
EM: wmoon@eos1.snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742 Korea, Republic of
AU: Jung, H
EM: hijung@kunsan.ac.kr
AF: Department of Ocean System Engineering, Kunsan National University, Kunsan, 573-701 Korea, Republic of
AU: Kim, K
EM: kykim@kangwon.ac.kr
AF: Department of Geophysics, Kangwon National University, Chuncheon, 200-701 Korea, Republic of
AB: The second crustal refraction experiment in Korea was carried out along a 335 km long survey profile in October 2004. The principal purpose of the study is to understand the crustal velocity structure and the tectonic setting of the Korea peninsula. The survey line runs along NNW-SSE direction in the central part of the southern Korea. A total of 196 portable seismometers including 26 three-component ones were deployed at approximately 1.7 km interval. Along the profile line, four shots were exploded in 95-150 m deep drill wells with charge sizes between 500 and 1000 kg of explosives. Seismic signals were recorded at a rate of 120 samples per second. The traveltimes of P wave phases, Pg, PiP, PmP, and Pn were identified and shear wave phases, Sg were also observable on a reduced traveltime plot. An iterative combination of ray tracing and least-squares inversion scheme (Zelt and Smith, 1992) resulted in a layered crustal P-velocity model in which the thickness varies from 30 km to 33 km. The crust appears thickest around the Okcheon belt in the central part, which coincides with the result from the first experiment (Cho et al., 2004). This also agrees with previous researches on crustal structure of the Korean Peninsula (Park et al., 2003; Chang et al., 2004; Kim et al., 2005). Several moderate mid-crustal reflections were recognized, one of which was considered to be representative of the Conrad.
DE: 3260 Inverse theory
DE: 7205 Continental crust (1219)
DE: 7218 Lithosphere (1236)
DE: 8180 Tomography (6982, 7270)
SC: Tectonophysics [T]
MN: Fall Meeting 2005