THE SEGMENTATION OF RUPTURE AND ESTIMATE OF EARTHQUAKE RISK ALONG THE NORTH MARGIN OF WESTERN QINLING FAULT ZONE

doi:10.3969/j.issn.0253-4967.2011.01.008

Abstract

Abstract:

We divide the north margin of Western Qingling Fault zone into six segments on the basis of new geology data,namely,Baoji,Tianshui,Wushan,Zhangxian,Huangxianggou and Guomatan segment from east to west.Each segment not only can rupture independently,but also can rupture together with others.The probability of seismic potential on these six segments and two combination segments is computed with the time-dependent seismic potential probability estimate method.We find from the result that,both the Huangxianggou and Zhangxian segments have the biggest probability of rupture in the future; and Tianshui segment is the second.If there will be a combined rupture,it is most likely to happen in Huangxianggou and Zhangxian segments,both of which have higher earthquake risk.We also compute b value along the fault zone.The image of b value indicates a high accumulated stress on the Huangxianggou and Tianshui segments.So we suppose that the two areas are the main locations where strong earthquakes may occur in the future.

Key words: the north margin of Western Qinling Fault, time-dependent seismic potential probability, b value image, stress accumulation

摘要：

根据最新地质考察和历史地震考证结果,西秦岭北缘断裂带从东到西可划分为宝鸡、天水、武山、漳县、黄香沟和锅麻滩共6个次级断裂段。上述断裂既具有单段破裂,又具有多段组合破裂的特征。利用时间相依的地震潜势概率评估方法,对这6个单段分别进行地震危险性概率评估,其中黄香沟段和漳县段发生单段破裂的可能性最大,天水段发生单段破裂的概率次之。若发生组合破裂,黄香沟段和漳县段组合破裂可能性大。同时,根据沿断裂带的b值扫描图像分析结果显示,黄香沟段和天水附近应力积累较高,这两个地区应是未来发生强震的主要段落,值得关注。

关键词: 西秦岭北缘断裂, 时间相依地震潜势概率, b值扫描, 应力积累

CLC Number:

P315.9

SHAO Yan-xiu, YUAN Dao-yang, WANG Ai-guo, LIANG Min-jian, LIU Kun, FENG Jian-gang. THE SEGMENTATION OF RUPTURE AND ESTIMATE OF EARTHQUAKE RISK ALONG THE NORTH MARGIN OF WESTERN QINLING FAULT ZONE[J]. SEISMOLOGY AND GEOLOGY, 2011, 33(1): 79-90.

邵延秀, 袁道阳, 王爱国, 梁明剑, 刘琨, 冯建刚. 西秦岭北缘断裂破裂分段与地震危险性评估[J]. 地震地质, 2011, 33(1): 79-90.

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