2017年精河6.6级地震余震序列重新定位和发震构造
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摘要
采用双差定位方法,利用中国地震台网的数据对2017年8月9日精河6.6级地震的余震序列进行了重新定位。截至2017年8月14日16时,共获得209个余震的重新定位结果。结果显示,余震主要呈近EW向或NWW向分布,余震区长约50km,宽约17km。余震分布在主震的西侧,推断此次地震单侧破裂。余震震源深度为1~25km,其中,震级较大余震深度为8~17km。精河地震序列的余震活动随时间呈起伏状衰减,震后2天内比较活跃,此后出现较快衰减。随时间推移,余震区呈现中西部衰减慢、东部衰减快的特点。此次地震震中距2011年精河5.0级地震震中21km,相比2011年精河地震,其震源更深,震级更大,但震源机制解相近,均为逆冲型。结合区域构造背景分析认为,库松木契克山前断裂为此次地震发震构造的可能性较大。
In this paper,the relocating of the aftershock sequence of the 2017 M_S6.6 Jinghe earthquake in Xinjiang was implemented using CENC data with the Double Difference relocation method. By the time of 16: 00 p.m. on August 14,2017,totally 209 aftershocks were relocated. It shows that the aftershocks are distributed along EW direction or NWW direction with the length of50 km and the width of 17 km. Since the most aftershocks are located at the western area of the epicenter,the main earthquake might rupture unilaterally from the east to the west. The hypocenters of the aftershock sequence ranges from 1 km to 25 km,among which most strong aftershocks range from 8 km to 17 km. The first 2 days after the mainshock is an active period of seismicity,after which it becomes inactive. Horizontally,the seismicity of the eastern aftershock area attenuates rapidly while the western area decays slower. The mainshock is much stronger and deeper compared with the 2011 M5.0 Jinghe earthquake which occurred 21 km away from this earthquake. But still the focal mechanism solutions of these two quakes are similar,and both are thrusting earthquakes. Considering the regional structure background,it is highly likely that the Kusongmuqike piedmont fault might be the causative structure of the earthquake.
In this paper,the relocating of the aftershock sequence of the 2017 M_S6.6 Jinghe earthquake in Xinjiang was implemented using CENC data with the Double Difference relocation method. By the time of 16: 00 p.m. on August 14,2017,totally 209 aftershocks were relocated. It shows that the aftershocks are distributed along EW direction or NWW direction with the length of50 km and the width of 17 km. Since the most aftershocks are located at the western area of the epicenter,the main earthquake might rupture unilaterally from the east to the west. The hypocenters of the aftershock sequence ranges from 1 km to 25 km,among which most strong aftershocks range from 8 km to 17 km. The first 2 days after the mainshock is an active period of seismicity,after which it becomes inactive. Horizontally,the seismicity of the eastern aftershock area attenuates rapidly while the western area decays slower. The mainshock is much stronger and deeper compared with the 2011 M5.0 Jinghe earthquake which occurred 21 km away from this earthquake. But still the focal mechanism solutions of these two quakes are similar,and both are thrusting earthquakes. Considering the regional structure background,it is highly likely that the Kusongmuqike piedmont fault might be the causative structure of the earthquake.
引文
鲍子文、高原,2017,天山构造带及邻区地壳各向异性,地球物理学报,60(4),1359~1375。
陈建波、沈军、李军等,2007,北天山西段库松木楔克山山前断层新活动特征初探,西北地震学报,29(4),335~340。
陈建波、谭明、吴国栋等,2012a,2011年10月16日新疆精河县5.0级地震灾害特征及发震构造,内陆地震,26(3),233~241。
陈建波、谭明、吴国栋等,2012b,2011年10月16日新疆精河县5.0级地震震害特征及原因,震灾防御技术,7(2),164~172。
邓起东,2007,中国活动构造图,北京:地震出版社。
冯先岳,1985,论新疆地震地质特征,地震地质,7(2),76~82。
冯先岳、邓起东、石监帮等,1991,天山南北缘活动构造及其演化,见:《活动断裂研究》编委会,活动断裂研究(第1期),1~16 ,北京:地震出版社。
国家地震局震害防御司,1995,中国历史强震目录:公元前23世纪-公元1911年,北京:地震出版社。
胡军、丁德轩、胡方秋等,1985,天山地区岩石圈动力学特征初探,新疆地震,3(2),85~94。
李杰、陈刚、魏文薪等,2016,基于GPS观测的北天山主要断裂现今构造运动特征研究,地震学报,38(5),751~760。
李志海、王海涛、赵翠萍等,2006,2003年新疆石河子5.4级地震序列重新定位及发震断层与机制分析,地震研究,29(2),109 ~113。
龙海英、高国英、聂晓红等,2008,北天山地区中强地震震源机制解分析,中国地震,24(1),23~30。
漆家福、陈书平、杨桥等,2008,准格尔-北天山盆山过渡带构造基本特征,石油与天然气地质,29(2),252~260。
邵学钟、张家茹、范会吉等,1996,天山造山带地壳结构与构造-乌鲁木齐-库尔勒地震转换波测深剖面,地球物理学报,39(3),336~346。
沈军、柏美祥、石广岭等,2011,新疆及邻区地震构造图简介,内陆地震,25(2),97~108。
沈军、吴传勇、陈建波等,2008,新疆主要逆断层-褶皱构造区基本地震构造特征与潜在震源划分问题,震灾防御技术,3(2),101~110。
陶钧政、吕正、朱诚等,1982,新疆板块构造基本轮廓,新疆大学学报(自然科学版),1,3~20。
杨少敏、李杰、王琪等,2008,GPS研究天山现今变形与断层活动,中国科学:D辑,38(7),872~880。
张培震、邓起东、杨晓平等,1996,天山的晚新生代构造变形及其地球动力学问题,中国地震,12(2),127~140。
中国地震局震害防御司,1999,中国近代地震目录:公元1912年-1990年,MS≥4.7,北京:中国科学技术出版社。
Waldhauser F,Ellsworth W L,2000,A double-difference earthquake location algorithm:Method and application to the northern Hayward Fault,Bull Seism Soc Am,90,1353~1368.
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(4)https://earthquake.usgs.gov/earthquakes/eventpage/us2000a65e#moment-tensor
(5)http://www.cea-igp.ac.cn/tpxw/275885.html
(6)http://www.globalcmt.org/CMTsearch.html
陈建波、沈军、李军等,2007,北天山西段库松木楔克山山前断层新活动特征初探,西北地震学报,29(4),335~340。
陈建波、谭明、吴国栋等,2012a,2011年10月16日新疆精河县5.0级地震灾害特征及发震构造,内陆地震,26(3),233~241。
陈建波、谭明、吴国栋等,2012b,2011年10月16日新疆精河县5.0级地震震害特征及原因,震灾防御技术,7(2),164~172。
邓起东,2007,中国活动构造图,北京:地震出版社。
冯先岳,1985,论新疆地震地质特征,地震地质,7(2),76~82。
冯先岳、邓起东、石监帮等,1991,天山南北缘活动构造及其演化,见:《活动断裂研究》编委会,活动断裂研究(第1期),1~16 ,北京:地震出版社。
国家地震局震害防御司,1995,中国历史强震目录:公元前23世纪-公元1911年,北京:地震出版社。
胡军、丁德轩、胡方秋等,1985,天山地区岩石圈动力学特征初探,新疆地震,3(2),85~94。
李杰、陈刚、魏文薪等,2016,基于GPS观测的北天山主要断裂现今构造运动特征研究,地震学报,38(5),751~760。
李志海、王海涛、赵翠萍等,2006,2003年新疆石河子5.4级地震序列重新定位及发震断层与机制分析,地震研究,29(2),109 ~113。
龙海英、高国英、聂晓红等,2008,北天山地区中强地震震源机制解分析,中国地震,24(1),23~30。
漆家福、陈书平、杨桥等,2008,准格尔-北天山盆山过渡带构造基本特征,石油与天然气地质,29(2),252~260。
邵学钟、张家茹、范会吉等,1996,天山造山带地壳结构与构造-乌鲁木齐-库尔勒地震转换波测深剖面,地球物理学报,39(3),336~346。
沈军、柏美祥、石广岭等,2011,新疆及邻区地震构造图简介,内陆地震,25(2),97~108。
沈军、吴传勇、陈建波等,2008,新疆主要逆断层-褶皱构造区基本地震构造特征与潜在震源划分问题,震灾防御技术,3(2),101~110。
陶钧政、吕正、朱诚等,1982,新疆板块构造基本轮廓,新疆大学学报(自然科学版),1,3~20。
杨少敏、李杰、王琪等,2008,GPS研究天山现今变形与断层活动,中国科学:D辑,38(7),872~880。
张培震、邓起东、杨晓平等,1996,天山的晚新生代构造变形及其地球动力学问题,中国地震,12(2),127~140。
中国地震局震害防御司,1999,中国近代地震目录:公元1912年-1990年,MS≥4.7,北京:中国科学技术出版社。
Waldhauser F,Ellsworth W L,2000,A double-difference earthquake location algorithm:Method and application to the northern Hayward Fault,Bull Seism Soc Am,90,1353~1368.
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(2)http://data.earthquake.cn
(3)http://geofon.gfz-potsdam.de/eqinfo/event.php?id=gfz2017plxq
(4)https://earthquake.usgs.gov/earthquakes/eventpage/us2000a65e#moment-tensor
(5)http://www.cea-igp.ac.cn/tpxw/275885.html
(6)http://www.globalcmt.org/CMTsearch.html