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
|
摘要
本文介绍了新疆主要逆断层-褶皱构造区的基本特征,并对其潜在震源划分问题进行了初步的讨论。北天山山前推覆构造及乌鲁木齐以南的逆断裂-褶皱构造相对比较简单,由根部断裂、推覆体和前缘逆断裂-褶皱构造所组成;强地震的极震区或地震动的高值区可能位于推覆构造的根部断裂附近,而地震地表破裂和同震地表变形则位于山前逆断层-褶皱带内。南天山的柯坪推覆构造、库车推覆构造、帕米尔东北缘的弧形推覆构造,虽然也由多排逆断裂-褶皱构造带组成,但是其中的规模巨大、发育时间较长的逆断裂-背斜带,往往具备发生强震的条件。强震的极震区分布与地震地表断层位置比较一致,可作为强震的潜在震源。盆地内的新的盲逆断层-褶皱构造也具备发生6.5—7.0 级地震的能力,应作为震级上限为 7.0 级的潜在震源。由于对逆断层-褶皱构造的深浅构造关系及发震模型认识的不足,在潜在震源划分中应考虑这种不确定性。同时在潜在震源区划分中,还应考虑地震构造区的地震活动历史及构造活动性参数。
The basic features of the major thrust fault-fold region of Xinjiang were introduced, as well as the problems on the determination of the potential earthquake source in these region were preliminarily discussed in this paper. The thrust systems on the piedmont of northern Tianshan and in the south of Urumqi city are comparatively simple in structure, which are composed of foot thrust fault, thrust sheet and front thrust fault-fold. It is very likely that high grade area of strong ground motion will located along the foot thrust fault and the surface rupture and deformation will appear along the front thrust fault-fold. The Keping thrust and Kuqa thrust, as well as the arcuate thrust in the northeastern margin of Pamir are also composed of foot thrust fault, thrust sheet and front thrust fault-fold. However, the large thrust faults which have undertaken long developing history, have the potential of occurring of strong earthquake. The distribution of high intensity areas of history earthquakes were consisted with the surface ruptures appeared along the front thrust faults. In this case, these front thrust fault-fold should be ascertained as the potential seismic source of strong earthquake. The new developed thrust fault-folds in basin region have possibility of earthquake MS6.5—7.0, which should be ascertained as the potential seismic source with upper limit magnitude of MS7.0. The deep structure and the relationship between deep and shallow structures were still not well studied and understood in the thrust fault-fold regions of Xinjiang. The uncertainty of occurrence model of strong earthquake in the thrust fault-fold region, as well as the parameters of historic seismicity and tectonic activity should be considered during the ascertainment of potential seismic source.
The basic features of the major thrust fault-fold region of Xinjiang were introduced, as well as the problems on the determination of the potential earthquake source in these region were preliminarily discussed in this paper. The thrust systems on the piedmont of northern Tianshan and in the south of Urumqi city are comparatively simple in structure, which are composed of foot thrust fault, thrust sheet and front thrust fault-fold. It is very likely that high grade area of strong ground motion will located along the foot thrust fault and the surface rupture and deformation will appear along the front thrust fault-fold. The Keping thrust and Kuqa thrust, as well as the arcuate thrust in the northeastern margin of Pamir are also composed of foot thrust fault, thrust sheet and front thrust fault-fold. However, the large thrust faults which have undertaken long developing history, have the potential of occurring of strong earthquake. The distribution of high intensity areas of history earthquakes were consisted with the surface ruptures appeared along the front thrust faults. In this case, these front thrust fault-fold should be ascertained as the potential seismic source of strong earthquake. The new developed thrust fault-folds in basin region have possibility of earthquake MS6.5—7.0, which should be ascertained as the potential seismic source with upper limit magnitude of MS7.0. The deep structure and the relationship between deep and shallow structures were still not well studied and understood in the thrust fault-fold regions of Xinjiang. The uncertainty of occurrence model of strong earthquake in the thrust fault-fold region, as well as the parameters of historic seismicity and tectonic activity should be considered during the ascertainment of potential seismic source.
引文
陈杰,曲国胜,胡军等,1997.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.地震地质,19(4):301—302.
冯先岳,1999.1985 年新疆乌恰地震烈度与发震构造.内陆地震,13(2):169—178.
郝敏,谢礼立,2007.9.21 台湾集集地震的烈度等震线.哈尔滨工业大学学报,39(2):169—172.
潘华,鄢家全,1995.潜在震源区概念的界定.国际地震动态,9 期:1—5.
冉勇康,杨晓平,徐锡伟等,2006.西南天山柯坪推覆构造东段晚第四纪变形样式与缩短速率.地震地质,28(2):181—193.
沈军,汪一鹏,赵瑞斌等,2001.帕米尔东北缘及塔里木盆地西北部弧形构造的扩展特征.地震地质,23(3):382—389.
沈军,李莹甄,汪一鹏,2004.地震构造的能量积累和释放特征与新疆天山部分地区地震危险性分析.中国地震,20(3):229—237.
沈军,陈建波,王翠等,2006a.2003 年 2 月 24 日新疆巴楚-伽师 6.8 级地震发震构造.地震地质,28(2):205—212.
沈军,吴传勇,李军等,2006b.库车坳陷活动构造的基本特征.地震地质,28(2):269—278.
沈军,宋和平,李军,2007.乌鲁木齐城市活断层发震构造模型初探.内陆地震,21(3):193—204.
沈军,宋和平,2008.乌鲁木齐城市活断层探测与地震危险性评价成果简介.地震地质,30(1):273—288.
宋方敏,闵伟,韩竹军等,2006.柯坪塔格推覆体的新生代变形与扩展.地震地质,28(2):224—233.
田勤俭,丁国瑜,郝平,2006.南天山及塔里木北缘构造带西段地震构造研究.地震地质,28(2):213—223.
王为民,赵连峰,李娟等,2005.1999 年台湾集集地震震源破裂过程.地球物理学报,48(1):132—147.
汪一鹏,沈军,2003.天山北麓活动构造基本特征.新疆地质,18(3):203—210.
杨晓平,邓起东,张培震,徐锡伟,于贵华,冯先岳,1998.北天山地区逆断裂-褶皱带构造与潜在震源区估计.地震地质,20(3):193—200.
尹光华,沈军,陈忠民等,1991.柯坪地震的震害评估.内陆地震,5(4):344—351.
张裕明,周本刚,沈得秀,2006.工程场地地震安全性评价工作中两个问题的讨论.震灾防御技术,1(3):
181—185.
张培震,王敏,甘卫军,2003.GPS 观测的活动断裂滑动速率及其对现今大陆动力作用的制约.地学前缘,10(特刊):8l—92.
赵瑞斌,沈军,李军,2001.1902 年新疆阿图什 81/4级地震形变特征与发震模式初探.地震地质,23(4):493—500.
周本刚,2004.论发震构造特性在潜在震源区参数确定中的应用.地震地质,26(4):751—760.
冯先岳,1999.1985 年新疆乌恰地震烈度与发震构造.内陆地震,13(2):169—178.
郝敏,谢礼立,2007.9.21 台湾集集地震的烈度等震线.哈尔滨工业大学学报,39(2):169—172.
潘华,鄢家全,1995.潜在震源区概念的界定.国际地震动态,9 期:1—5.
冉勇康,杨晓平,徐锡伟等,2006.西南天山柯坪推覆构造东段晚第四纪变形样式与缩短速率.地震地质,28(2):181—193.
沈军,汪一鹏,赵瑞斌等,2001.帕米尔东北缘及塔里木盆地西北部弧形构造的扩展特征.地震地质,23(3):382—389.
沈军,李莹甄,汪一鹏,2004.地震构造的能量积累和释放特征与新疆天山部分地区地震危险性分析.中国地震,20(3):229—237.
沈军,陈建波,王翠等,2006a.2003 年 2 月 24 日新疆巴楚-伽师 6.8 级地震发震构造.地震地质,28(2):205—212.
沈军,吴传勇,李军等,2006b.库车坳陷活动构造的基本特征.地震地质,28(2):269—278.
沈军,宋和平,李军,2007.乌鲁木齐城市活断层发震构造模型初探.内陆地震,21(3):193—204.
沈军,宋和平,2008.乌鲁木齐城市活断层探测与地震危险性评价成果简介.地震地质,30(1):273—288.
宋方敏,闵伟,韩竹军等,2006.柯坪塔格推覆体的新生代变形与扩展.地震地质,28(2):224—233.
田勤俭,丁国瑜,郝平,2006.南天山及塔里木北缘构造带西段地震构造研究.地震地质,28(2):213—223.
王为民,赵连峰,李娟等,2005.1999 年台湾集集地震震源破裂过程.地球物理学报,48(1):132—147.
汪一鹏,沈军,2003.天山北麓活动构造基本特征.新疆地质,18(3):203—210.
杨晓平,邓起东,张培震,徐锡伟,于贵华,冯先岳,1998.北天山地区逆断裂-褶皱带构造与潜在震源区估计.地震地质,20(3):193—200.
尹光华,沈军,陈忠民等,1991.柯坪地震的震害评估.内陆地震,5(4):344—351.
张裕明,周本刚,沈得秀,2006.工程场地地震安全性评价工作中两个问题的讨论.震灾防御技术,1(3):
181—185.
张培震,王敏,甘卫军,2003.GPS 观测的活动断裂滑动速率及其对现今大陆动力作用的制约.地学前缘,10(特刊):8l—92.
赵瑞斌,沈军,李军,2001.1902 年新疆阿图什 81/4级地震形变特征与发震模式初探.地震地质,23(4):493—500.
周本刚,2004.论发震构造特性在潜在震源区参数确定中的应用.地震地质,26(4):751—760.
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