Significant anomalies were observed at the geomagnetic stations in the southwest region of China before the Yingjiang M_S6. 1 earthquake and the Ludian M_S6. 5 earthquake in 2014.We processed the geomagnetic vertical ...Significant anomalies were observed at the geomagnetic stations in the southwest region of China before the Yingjiang M_S6. 1 earthquake and the Ludian M_S6. 5 earthquake in 2014.We processed the geomagnetic vertical component diurnal variation data by the spatial correlation method. The results show that during the period from April 1 to May 20,2014,there existed quasi-synchronous decrease changes in the coefficient curves between the five geomagnetic stations of Guiyang,Hechi,Nanshan,Muli,Yongning and Xinyi and Hongshan stations. Furthermore,there was a high gradient zone in the normalized correlation coefficient contour map with background values removed. The epicenters of the Yingjiang M_S6. 1 earthquake and the Ludian M_S6. 5 earthquake are located in the gradient zone or near the gradient zone.展开更多
本文采用"剪切-粘贴"(CAP,Cut And Paste)方法 ,分别利用区域地震台网的宽频带记录和全球地震台网宽频带记录,独立反演和联合反演了云南盈江2014年5月24日5.6级和5月30日6.1级地震震源参数。结果表明,采用近震和远震数据联合...本文采用"剪切-粘贴"(CAP,Cut And Paste)方法 ,分别利用区域地震台网的宽频带记录和全球地震台网宽频带记录,独立反演和联合反演了云南盈江2014年5月24日5.6级和5月30日6.1级地震震源参数。结果表明,采用近震和远震数据联合反演结果更为稳定,5月24日5.6级地震震源机制解两个节面分别为:走向153°/倾向90°/滑动角171°和243°/81°/0°,5月30日6.1级地震两个节面分别为172°/72°/180°和82°/90°/-18°。两次地震断层参数较为接近,均为走滑型地震,结合区域构造背景和地震序列重定位结果认为其发震断层可能为近南北向苏典断裂。震源机制解反演结果与震源区历史地震震源机制解和利用其它方法得到的机制解相近,也符合震源区的区域应力场特征。两次地震反演最佳震源深度分别为8km和6km,均为发生在上地壳的浅源地震,表明苏典断裂在此部位可能并没有切割到地壳深部。展开更多
Objective The 2014 Ludian Mw6.1 earthquake in Yunnan occurred in a mountainous area with complex tectonics and topography, which caused serious damage as well as co-seismic landslides of an unusual large scale. Becau...Objective The 2014 Ludian Mw6.1 earthquake in Yunnan occurred in a mountainous area with complex tectonics and topography, which caused serious damage as well as co-seismic landslides of an unusual large scale. Because the suspected seismogenic faults on the surface, distribution of aftershocks and focal mechanism solutions are not consistent, it remains difficult to determine what is the real causal fault or seismogenic structure for this event. Actually, it may imply the complicity of the seismic source at depth. In addition, the distribution of the co- seismic landslides also exhibits some diffusion that is different from general eases, likely associated with the seismic focus structure.展开更多
基金sponsored by the Spark Program for Earthquake Science and Technology,China Earthquake Administration(Serial No.XH17010Y)the Seismic Tracking and Orientation Task,China Earthquake Administration(Serial No.2018010401)Major Scientific and Technical Project of Science and Technology Department of Inner Mongolia in 2016(Strong Earthquake Track in the Short Stage and Integration Innovation of Stereoscopic Observation Technology in Space and Ground)
文摘Significant anomalies were observed at the geomagnetic stations in the southwest region of China before the Yingjiang M_S6. 1 earthquake and the Ludian M_S6. 5 earthquake in 2014.We processed the geomagnetic vertical component diurnal variation data by the spatial correlation method. The results show that during the period from April 1 to May 20,2014,there existed quasi-synchronous decrease changes in the coefficient curves between the five geomagnetic stations of Guiyang,Hechi,Nanshan,Muli,Yongning and Xinyi and Hongshan stations. Furthermore,there was a high gradient zone in the normalized correlation coefficient contour map with background values removed. The epicenters of the Yingjiang M_S6. 1 earthquake and the Ludian M_S6. 5 earthquake are located in the gradient zone or near the gradient zone.
文摘本文采用"剪切-粘贴"(CAP,Cut And Paste)方法 ,分别利用区域地震台网的宽频带记录和全球地震台网宽频带记录,独立反演和联合反演了云南盈江2014年5月24日5.6级和5月30日6.1级地震震源参数。结果表明,采用近震和远震数据联合反演结果更为稳定,5月24日5.6级地震震源机制解两个节面分别为:走向153°/倾向90°/滑动角171°和243°/81°/0°,5月30日6.1级地震两个节面分别为172°/72°/180°和82°/90°/-18°。两次地震断层参数较为接近,均为走滑型地震,结合区域构造背景和地震序列重定位结果认为其发震断层可能为近南北向苏典断裂。震源机制解反演结果与震源区历史地震震源机制解和利用其它方法得到的机制解相近,也符合震源区的区域应力场特征。两次地震反演最佳震源深度分别为8km和6km,均为发生在上地壳的浅源地震,表明苏典断裂在此部位可能并没有切割到地壳深部。
基金supported by the National Natural Science Foundation of China(grant No.41572194)the Institute of Geology,China Earthquake Administration(grant No.IGCEA1604)the National Key Basic Research Program of China(grant No.2013CB733205)
文摘Objective The 2014 Ludian Mw6.1 earthquake in Yunnan occurred in a mountainous area with complex tectonics and topography, which caused serious damage as well as co-seismic landslides of an unusual large scale. Because the suspected seismogenic faults on the surface, distribution of aftershocks and focal mechanism solutions are not consistent, it remains difficult to determine what is the real causal fault or seismogenic structure for this event. Actually, it may imply the complicity of the seismic source at depth. In addition, the distribution of the co- seismic landslides also exhibits some diffusion that is different from general eases, likely associated with the seismic focus structure.
