摘要
利用云南测震台网波形数据及观测报告,结合构造背景及历史地震活动,从序列活动特征及参数、较大地震的震源机制解及序列精定位等方面分析了2015年3月1日云南沧源MS5.5地震序列的发震构造及序列分布演化特征。结合震源机制解结果及震区构造,本次地震的发震构造可能为南汀河断裂带(西支)、呈左旋走滑。本次地震的余震活动较弱,序列随时间衰减较快,具有明显的阶段性;双差重定位结果反映其主体破裂区为北北东向、近似竖直的带状区域,可能为单侧破裂,且后期的余震呈向浅部及外围区域扩散的趋势。
Using waveform data from seismic network of Yunnan province and their corresponding observation report,combined with the tectonic background and historical seismicity,we discussed seismogenic structure and the distribution and temporal evaluation variation of Cangyuan MS5. 5 earthquake sequence in Yunnan on M ar. 1,2015 from the activity characteristics and parameters of the sequence,the focal mechanism solutions of larger events as well as the accurate relocation of the sequence etc.. Referring to the focal mechanism solutions and the tectonics in epicenter area,we indicated that the seismogenic structure of Cangyuan earthquake is the west branch of Nantinghe Fault which appearred to be a right-lateral strike-slip faulting. It is showed that the seismicity of aftershock sequences remain low,decayed rapidly with time and appeared the obvious phased. The spatial distribution of the sequences which were relocated by the double-difference relocation algorithm showed that the main rupture area was a zonal area of NNEin approximately vertical direction. It seemed to be a unilateral rupture,furthermore,the distribution of the later aftershocks showed the scatter trend to the shallower and outer region of the epicenter.
出处
《地震研究》
CSCD
北大核心
2015年第3期333-340,共8页
Journal of Seismological Research
基金
前震识别技术研究(2014020101)
云南省地震局科技人员传帮带项目联合资助
关键词
云南沧源Ms5.5地震
双差重定位
南汀河断裂带(西支)
地震序列
发震构造
Cangyuan MS5.5 earthquake
the double-difference relocation
Nantinghe Fault（west branch）
earthquake sequence
seismogenic structure
