1950年以来帕米尔东北缘—西昆仑地区7级左右地震后新疆地区中强地震活动状态分析
|
摘要
本文类比分析了1950年以来帕米尔东北缘—西昆仑地区7级左右地震发生后3年内新疆地区中强以上地震的活动状态,并进一步讨论了2008年于田7.3级和乌恰6.8级地震后新疆地区的地震活动特点。结果表明,1950年以来帕米尔东北缘—西昆仑地区7级左右地震发生后,新疆地区应变能释放相对较为充分,震后3年通常无6.5级以上强震发生;7级左右地震后3年新疆地区5级以上地震频度总体呈下降趋势,2008年于田7.3级地震后5级以上地震出现的活跃—平静的显著差异性活动特征与1974年乌兹别里山口7.3级地震和1996年喀喇昆仑山口7.1级地震后较为相似。此外,结合新疆地区强震活动的动力学环境作用和帕米尔东北缘—西昆仑地区7级左右地震的震源机制特征,初步探讨分析了该区7级左右地震后3年内新疆地区中强以上地震空间活动特征的可能成因。
We analyze moderate-strong earthquake activities in Xinjiang within 3 years after earthquakes with magnitude 7 or so in the Northeast edge of Pamir—West Kunlun area since 1950,and discuss further seismic activity in Xinjiang after the 2008 Yutian MS7.3 earthquake and Wuqia MS6.9 earthquake.Our study shows that strain energy in Xinjiang released fully after the earthquakes with magnitude 7 or so since 1950 in the Northeast edge of Pamir—West Kunlun area,and no strong earthquake with magnitude over 6.5 occurred within 3 years after these earthquakes with magnitude 7 or so;the annual frequency of MS≥5 earthquakes in Xinjiang appears downtrend within 3 years after these earthquakes with magnitude 7 or so,and the differential character of seismicity—quiescence of MS≥5 earthquakes after the 2008 Yutian MS7.3 earthquake is similar to that after the 1974 MS7.3 earthquake of Uzbel Mountain pass and the 1996 MS7.1 earthquake in the Karakorum Mountain pass.In addition,Combining dynamic condition of strong earthquake activities in Xinjiang and focal mechanism feature of the earthquakes of magnitude 7 or so in the Northeast edge of Pamir—West Kunlun area,we discuss possible causes for spatial activity features of moderate-strong earthquakes in Xinjiang within 3 years after magnitude 7 or so earthquakes.
We analyze moderate-strong earthquake activities in Xinjiang within 3 years after earthquakes with magnitude 7 or so in the Northeast edge of Pamir—West Kunlun area since 1950,and discuss further seismic activity in Xinjiang after the 2008 Yutian MS7.3 earthquake and Wuqia MS6.9 earthquake.Our study shows that strain energy in Xinjiang released fully after the earthquakes with magnitude 7 or so since 1950 in the Northeast edge of Pamir—West Kunlun area,and no strong earthquake with magnitude over 6.5 occurred within 3 years after these earthquakes with magnitude 7 or so;the annual frequency of MS≥5 earthquakes in Xinjiang appears downtrend within 3 years after these earthquakes with magnitude 7 or so,and the differential character of seismicity—quiescence of MS≥5 earthquakes after the 2008 Yutian MS7.3 earthquake is similar to that after the 1974 MS7.3 earthquake of Uzbel Mountain pass and the 1996 MS7.1 earthquake in the Karakorum Mountain pass.In addition,Combining dynamic condition of strong earthquake activities in Xinjiang and focal mechanism feature of the earthquakes of magnitude 7 or so in the Northeast edge of Pamir—West Kunlun area,we discuss possible causes for spatial activity features of moderate-strong earthquakes in Xinjiang within 3 years after magnitude 7 or so earthquakes.
引文
[1]白超英.从板块碰撞看新疆地震活动的迁移[J].西北地震学报,1992,14(3):90-92.
[2]潘家伟,李海兵,Van der Woerd J,等.青藏高原西北部帕米尔东北缘构造地貌与活动构造研究[J].第四纪研究,2009,29(3):586-598.
[3]王海涛,李莹甄,屠泓为.新疆历史地震目录完整性分析[J].内陆地震,2006,20(1):10-17.
[4]陈杰,曲国胜,胡军,等.帕米尔北缘弧形推覆构造带东段的基本特征与现代地震活动[J].地震地质,1997,19(4):301-312.
[5]宁杰远,藏绍先.帕米尔-兴都库什地区地震空间分布特征及应力场特征[J].地球物理学报,1990,33(6):657-669.
[6]许志琴,戚学祥,杨经绥,等.陈方远.西昆仑康西瓦韧性走滑剪切带的两类剪切指向、形成时限及其构造意义[J].地质通报,2007,26(10):1 252-1 261.
[7]朱令人.新疆通志(十一卷,地震志)[M].乌鲁木齐:新疆人民出版社,2002.309-310.
[8]王盛泽,高国英.新疆及邻近地区现代构造应力场的区域特征[J].地震学报,1992,14(增刊):612-620.
[9]高国英,温和平,聂晓红.1991—2002年新疆中强震震源机制解分析[J].地震,2005,25(1):81-87.
[10]高国英,温和平.帕米尔东北侧现代构造应力场与地震活动特征研究[J].中国地震,2000,16(2):176-184.
[11]张国民,李献智,耿鲁明.印度板块北边界地震活动和中国大陆地震[J].地震,1994,14(3):1-9.
[2]潘家伟,李海兵,Van der Woerd J,等.青藏高原西北部帕米尔东北缘构造地貌与活动构造研究[J].第四纪研究,2009,29(3):586-598.
[3]王海涛,李莹甄,屠泓为.新疆历史地震目录完整性分析[J].内陆地震,2006,20(1):10-17.
[4]陈杰,曲国胜,胡军,等.帕米尔北缘弧形推覆构造带东段的基本特征与现代地震活动[J].地震地质,1997,19(4):301-312.
[5]宁杰远,藏绍先.帕米尔-兴都库什地区地震空间分布特征及应力场特征[J].地球物理学报,1990,33(6):657-669.
[6]许志琴,戚学祥,杨经绥,等.陈方远.西昆仑康西瓦韧性走滑剪切带的两类剪切指向、形成时限及其构造意义[J].地质通报,2007,26(10):1 252-1 261.
[7]朱令人.新疆通志(十一卷,地震志)[M].乌鲁木齐:新疆人民出版社,2002.309-310.
[8]王盛泽,高国英.新疆及邻近地区现代构造应力场的区域特征[J].地震学报,1992,14(增刊):612-620.
[9]高国英,温和平,聂晓红.1991—2002年新疆中强震震源机制解分析[J].地震,2005,25(1):81-87.
[10]高国英,温和平.帕米尔东北侧现代构造应力场与地震活动特征研究[J].中国地震,2000,16(2):176-184.
[11]张国民,李献智,耿鲁明.印度板块北边界地震活动和中国大陆地震[J].地震,1994,14(3):1-9.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心