• Journal of the Korean Geophysical Society
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• v.2 no.4
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• pp.235-240
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• 1999

From the seismic network data of the Korea Institute of Geology, Mining & Materials during 1995-1996, we derived a composite fault-plane solution of the microearthquakes occurred in the Yangsan fault area. The composite fault-plane solution of nine events shows the orientation of fault 15 ± 3°in strike, 60 ± 8°in dip and 140°in rake or 128 ± 3°in strike, 56 ± 8°in dip and 37°in rake. The compressional axis of the stress field trends ENE to WSW, and this field suggests strike-slip motion with thrust component. The result is consistent with the 1996 Yeong-weol event and the stress field in and around the Korean Peninsula, previously reported.

• Journal of the Korean Geophysical Society
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• v.3 no.4
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• pp.245-250
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• 2000

By using amplitude ratios (SV/P, SH/P, SV/SH) and P and S wave polarities, we obtained fault plane solutions of the June 26, 1997 Kyong-ju earthquake. The solutions show $150{\pm}4^{\circ}$ in strike, $63{\pm}6^{\circ}$ in dip and $65{\pm}7^{\circ}$ in rake, or $18{\pm}12^{\circ}$ in strike, $26{\pm}3^{\circ}$ in dip and $120{\pm}5^{\circ}$ in rake. This result implies the stress field trending ENE-WSW, which is remarkably consistent with the previous results obtained from the moment tensor inversion, and from the composite fault plane solution for the events occurred around the Yangsan fault area.

• Journal of the Korean earth science society
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• v.22 no.4
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• pp.292-300
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• 2001

By using two methods we obtained plane solutions for 5 groups of earthquakes including 13 events, which occurred in the central region of South Korea after December 1997. The first method is the composite fault plane solution by P wave polarity, and the second the solution by amplitude ratio (SV/P, SH/P, SV/SH) and P and S wave polarities. The two method results show similar results. The strike of fault is in the direction of NNE-SSW and WNW-ESE with the movement of strike-slip or strike-slip including thrust component. The compressional axis of the stress field dominantly trends ENE-WSW or NE-SW. The results are almost consistent with the other main events occurred in and around the Korean Peninsula.