The source parameters of four earthquakes with magnitude larger than 4.0 nearby the offshore Sinan are analyzed. The waveform inversion method is used for analyzing the source parameters of two events (20 August 2012 and 21 April 2013) with C&B and AK135-c crustal velocity structure models. The source parameters of the other two events (26 July 1994 and 23 March 2003) are obtained from references. Focal mechanisms of the events are strike slip faulting or strike slip faulting with a thrust component. The directions of P-axes of the events are ENE-WSW or NE-SW which are similar to previous studies on P-axes in and around the Korean peninsula. With regard to the events nearby the offshore Sinan, the regional stress, rather than being local stress, is seen to be the result of the combination of tectonic forces from the compression of plates colliding to the Eurasian Plate.

 ABSTRACT  1. 서 론  2. 본 론   2.1 자료처리   2.2 2012년 8월 20일 지진   2.3 2013년 4월 21일 지진   2.4 1994년 7월 26일 지진과 2003년 3월 23일 지진   2.5 신안 앞바다 중규모 지진들의 발진기구  3. 결 론  감사의 글  REFERENCES

• 최호선(한국원자력안전기술원 구조부지평가실) | Choi, Hoseon