Fig 3 - uploaded by Ki Young Kim
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Composite data obtained through merging the two shot gathers, sorting by distance, and selecting nearer source-receiver offset data at each station. The horizontal axis is distance from the Seosan station and the vertical axis is travel time.
Source publication
In order to reveal the perspective of velocity structure in the southern part of the Korean peninsula, a seismic experiment
was carried out along a WNW-ESE profile of 294-km length in December, 2002. In 100-m deep drill-holes, seismic explosives
of 1000 and 500 kg were detonated on the west coast and near the center of the profile, respectively. Th...
Contexts in source publication
Context 1
... and analysis described below. Then geometrical spreading corrections were applied to the data with a gain function proportional to square of recorded time. Non-reflection early arriving seismic energy was muted out carefully so as not to be included in reflection image, and then the two shot-gathers were merged and sorted by reflection point (Fig. ...
Context 2
... 4 shows P-wave image of the reflection Moho ( Klemperer et al., 1986) near 10.4 s at the western-most trace (x = 0.12 km). While the correct NMO velocity of 6.20 km/s yields 'assumed' proper images of the reflection boundary ( Fig. 4b), over-correction ( Fig. 4a) and under-cor- rection ( To analyze moveout velocities and identify possible reflec- tion boundaries of P waves, the data in Figure 3 were moved out according to Equations (1) and (2) with constant veloc- ities in the range of 3.70~6.60 km/s at a 0.10 km/s interval for P-wave images and 3.35~3.65 ...
Citations
Earthquakes in the Korean Peninsula occur along the faults formed and boundaries between major geological units ruptured due to violent tectonic activities during the Mesozoic. E-W and/or ENE-SSW compressive stress regime resulting from collisions between the Eurasian plate and neighbouring the Indian plate, the Pacific plate and the Philippine plate trigger Korean earthquakes of thrust faulting with predominant strike-slip components along the mostly NNE-SSW trending active faults. Seismicity of the Korean peninsula has been moderate to low during the past 20 centuries except for the period from the 15th to the 18th centuries of exceptionally high seismicity, showing the typical irregularity of intraplate seismicity. The structure of the Korean peninsula is rather homogeneous without the Conrad discontinuity sharply dividing the upper and lower crust. Lateral heterogeneities exist in the crust. The crust with an average thickness of about 33 km is thicker in the mountainous region than the plain due to the Airy-type isostatic equilibrium maintained in the peninsula. Crustal P-wave velocity with average of about 6.3 km/sec increases gradually from the near surface to the Moho. The upper mantle P-wave (Pn) velocity is about 7.8 km/sec.
