• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.4 s.15
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• pp.43-54
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• 2004

The broadband receiver functions are developed from teleseismic P waveforms recorded at Wonju(KSRS), Inchon(IRIS), and Pohang(PHN), and are analyzed to examine the crustal structure beneath these stations. The teleseismic receiver functions are inverted in the time domain of the vertical P wave velocity structures beneath the stations. Clear P-to-S converted phases from the Moho interface are observed in teleseismic seismograms recorded at these stations. The crustal velocity structures beneath the stations are estimated by using the receiver function inversion method(Ammon et al., 1990). The general features of inversion results are as follows: (1) For the Inchon station, the Conrad discontinuity exists at 17.5 Km(SW) deep and the Moho discontinuity exists at 29.5 Km(NW) and 30.5 Km(SE, SW) deep. (2) The shallow crustal structure beneath Wonju station may be covered with a sedimentary rock of a 3 Km thickness. The average Moho depth is assumed about 33.0 Km, and the Conrad discontinuity may exist at 17.0 Km(NE) and 21.0 Km(NW) deep. (3) For Pohang station, the thickness of shallow sedimentary layer is a 3.0 Km in the direction of NE and NW. The Moho depth is 28.0 Km in the direction of the NE and NW. The Conrad discontinuity can be estimated to be existed at 21.0 Km deep for the NE and NW directions.

• Journal of the Korean earth science society
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• v.30 no.2
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• pp.153-164
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• 2009

We examined the regional 1-D deep resistivity structure of the Korean Peninsula using MT data acquired at seven sites located in the Kyongsang Basin and Kyonggi Massif. At the sites located in the Kyongsang Basin, surrounding sea distorts observed MT response and hence this distortion, so called "sea effect", is corrected using an iterative tensor stripping method. The 1-D layered inversion results for the seven MT sites reveal 4 layered structure, which is composed of 1) near surface layer, 2) upper crust, 3) lower crust and upper mantle, and 4) asthenosphere from the surface downward. Conrad interface, which is a boundary between upper and lower crust, is distinctly identified beneath all the MT sites. Conrad interface depth is estimated to about be 17km in the Kyongsang Basin and about 12km in the Kyonggi Massif, while the upper crust of the Kyongsang Basin is about 5 times more resistive than that of the Kyonggi Massif. Finally, asthenosphere is inferred to exist below a depth of approximately 100km with a resistivity of 200-300 ohm-m.