HR: 17:00h
AN: T54A-05    [Abstracts]
TI: Moho Depth and Crustal Vp/Vs Variation in Southern Korea From Teleseismic Receiver Functions: Implication for Tectonic Affinity Between Korean Peninsula and China
AU: * Chang, S
EM: joshua@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, Shillim-dong Gwanak-gu, Seoul, 151-747 Korea, Republic of
AU: Baag, C
EM: baagce@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, Shillim-dong Gwanak-gu, Seoul, 151-747 Korea, Republic of
AB: There have been debates on how the two massifs in southern Korea (the Gyeonggi Massif and the Yeongnam Massif) are tectonically related to the two cratons in China (North China Craton and South China Craton). The Moho depth and Vp/Vs ratio were estimated from the receiver function analysis at 24 broadband seismic stations in southern Korea in order to find the tectonic affinity between Korean Peninsula and China. The Moho depth varies from 23.9 km to 33.5 km; the depths are shallower than those of the previous results obtained assuming a Poisson solid in the joint analysis of receiver functions and surface wave dispersion. Vp/Vs ratio distribution ranges from 1.70 to 1.81. Higher values concentrate in the southern part of Korean Peninsula which corresponds roughly to the Yeongnam Massif, while lower ones distribute in the central part approximately in accord with the Gyeonggi Massif. Considering the similarity of Vp/Vs ratios among massifs in Korea and cratons in China, it might be said that the Yeongnam Massif is related to the North China Craton, while the Gyeonggi Massif to the South China Craton. This is supported by the fact that the average crustal velocity is generally proportional to the Vp/Vs ratio in southern Korea, implying the major factor for Vp/Vs ratio is the composition of the crust, rather than partial melting or crustal fluids.
DE: 7203 Body waves
DE: 7205 Continental crust (1219)
DE: 7218 Lithosphere (1236)
DE: 8103 Continental cratons
SC: Tectonophysics [T]
MN: Fall Meeting 2005