2011年腾冲中强地震序列震源机制和发震构造研究

2011年腾冲地区连续发生了3次中强地震,本文运用全波形模拟的方法研究了这3次中强地震序列的震源机制解,并对地震序列进行了重定位。笔者结合由震源机制解及重定位结果对其发震构造进行了分析,认为3次中强地震及序列均位于同一发震构造,呈北西走向,破裂面倾角陡直,在近水平的北北东向压应力作用下作右旋水平走滑错动,断层较浅仅限于上地壳,活动过程有向深部发展的趋势;震源区附近无明显已知构造与发震构造相对应,发震构造可能为未知隐伏构造。

Focal Mechanisms and Seismogenic Structures of Tengchong Mediate-Strong Earthquake Sequences in 2011

Using the data recorded by the Yunnan Digital Seismic Network, we calculate the focal mechanisms of Tengchong mediate-strong earthquake sequences in 2011. We also relocate three earthquake sequences. Based on the results of focal mechanisms and relocation we analyze the seismogenic structure. Our results suggest that three mediate-strong earthquakes and aftershocks occurred on the same seismogenic structure which is a NW striking fault with steep fault plane. The tectonic stress field in source areas is oriented as NNE, in almost horizontal compressive stress field. The fault is a right-lateral strike slip fault cutting upper crust from shallow toward deep place. We infer that three earthquake sequences are caused by an unknown hidden fault buried in Tengchong area.