Geosciences Journal

The Association of Korean Geoscience Societies (한국지질과학협의회)
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Seismic reflection image of the crust structure along the KCRT-2002 profile in the southern Korean peninsula

Kim, Ki-Young;Lee, Jung-Mo;Baag, Chang-Eob;Moon, Woo-Il;Jung, Hee-Ok;Lee, So-Young

  • Published : 20070900
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Abstract

In order to reveal the perspective of velocity struc-ture in the southern part of the Korean peninsula, a seismic exper-iment was carried out along a WNW-ESE profile of 294-km lengthin December, 2002. In 100-m deep drill-holes, seismic explosives of1000 and 500 kg were detonated on the west coast and near thecenter of the profile, respectively. The seismic signals were detectedby 198 portable seismometers spaced approximately at an 1.5 kminterval and digitally recorded for 115 s at an 120-Hz samplingrate. Normal moveout corrections were applied to yield reflectionimages for P, S, and PS converted waves followed by time-to-depthconversion through forward modeling of travel times using thefourth-order equation for wide angle reflections. Three distinctreflection events are identified at average two-way travel times of4.90, 8.02, and 10.99 s on the NMO corrected P-wave sections.Their converted depths are 13.71, 23.37, and 33.67 km, respec-tively, and the P-wave interval velocities between the depth bound-aries including the free surface are 5.60, 6.19, and 6.96 km/s fromtop to bottom. The reflection Moho is imaged as a sharp boundaryin the middle of the profile while multi-layers are featured nearboth ends of the profile. Key words : velocity structure, Korean peninsula, reflection image,fourth-order equation, reflection Moho

Keywords

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