[关键词]
[摘要]
利用CAP 方法反演了2012 年6 月30 日新源- 和静MS6. 6 地震序列震源机制解。反演得到MS6. 6 地震节面Ⅰ的参数为:走向299°,倾角68°,滑动角164°;节面Ⅱ的参数为:走向35°,倾角75°,滑动角23°;P 轴方位角166°,倾角5°,T 轴方位角258°,倾角26°;矩震级Mw 为6. 3;矩心深度为21km。此次地震序列破裂优势方向为NWW,倾角以60° ~ 90°为主,滑动角以± 180° ± 30°为主;P 轴方位的优势取向为近NS 向,T 轴优势取向为近EW 向。初步分析表明,主震节面Ⅰ为发震断层,是走向为NWW、近乎直立的左旋走滑断层。此次6. 6 级地震震源断错性质和主压应力方向以及序列P 轴优势方位与震源区周围构造应力场特征基本一致。
[Key word]
[Abstract]
Using the CAP method to invert the focal-mechanism solution of the Xinyuan-Hejing MS6. 6 earthquake on June 30,2012. The result shows that the best double couple solution of the MS6. 6 event is 299°,68° and 164° for strike,dip and rake angles respectively. The other nodal planes are 35°,75° and 23°. The azimuth and dip angle of P axis are 166° and 5°,those of T axis are 258° and 26°. The moment magnitude is 6. 3. The estimated focal depth is about 21km. The predominant rupture direction of this seismic sequence is NWW. The dip angles are between 60° and 90°. The rake angles are basically ± 180° ± 30°. The predominant strike of the azimuthal angle of P axis is near NS and T axis is near EW. Preliminary analysis indicates that nodal section. One is the seismogenic fault and NWW-trend and nearly upright left-lateral strikeslip fault. The displacement property and the principal compressive stress of this MS6. 6 earthquake focus and P axis preponderant orientation of this seismic sequence agree with the tectonic stress field's characteristics of the focal area around.
[中图分类号]
[基金项目]
地震科技星火计划攻关项目(XH13028Y)和测震台网青年骨干培养专项(20120105)联合资助