陇南市活断层地震危险性评估  

Seismic Hazard Assessment for Active Faults of Longnan City

作　　者：邵延秀[1,2,3] 袁道阳[1,2] 何文贵[1,2] 刘兴旺[1,2] 郑文俊[3] 刘洪春[1] 张有龙[1] 王爱国[1,2] 

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000 [2]兰州地球物理国家野外科学观测研究站,甘肃兰州730000 [3]中国地震局地质研究所,北京100029

出　　处：《地震工程学报》2014年第3期645-655,共11页China Earthquake Engineering Journal

基　　金：中国地震局地震预测研究所基本科研业务费专项(2012IESLZ08);汶川地震甘肃省灾后重建项目和国家科技支撑计划课题(2011BAK12B05)

摘　　要：在甘肃省陇南市活断层探测与地质填图研究的基础上,归纳了开展地震危险性评估所需的主要活动断裂的基本活动性参数;采用震级—破裂尺度关系、震级—频度关系等方法评估了陇南市相关断裂(带)的潜在最大震级和平均复发间隔;利用时间相依的地震潜势概率模型和泊松分布模型评估了各断裂或断层小区在未来50、100、200年内发生破坏性地震的概率。同时利用b值空间图像扫描的方法给出了研究区的b值图像,分析了高应力区的地震危险性。通过对以上结果的综合分析,结果表明盖山—迭山断裂或光盖山—迭山断层小区的西端表现为高应力累积区,且发生破坏性地震的概率较高,是未来危险程度较高的断裂段。。Based on active fault mapping in Longnan City, Gansu Province, we determine in this study parameters used in seismic hazard assessment for active faults. Five main fault zones are i-dentified. The first is the Diebu -Bailongjiang fault zone, which ruptured during the M7 earth-quake in 186 BC. The second is the Guanggaishan - Dieshan fault zone, which is separated into three main strands. The north strand had been found to cause a paleo-earthquake, although the Pingding-Huama strand had a significantly faster slip rate. The Hanan-Qingshanwan-Daoxizi fault zone is the third. A surface rupture of approximately 3.5km long was found in the Zhuyuan-ba strand. The fourth is the Lianddang-Jiangluo fault zone, which had strong activity in the Hol-ocene. The fifth is the Wudu-Kangxian fault zone, in which four paleo-earthquakes have occurred since the Late Pleistocene. We estimated potential maximum earthquake magnitude and repeat in-terval time with magnitude-rupture length and magnitude-frequency relationships for every fault or fault sub-area. The probability of destructive earthquake occurrence in the future 50, 100, and 200 years was computed with a time-dependent seismic potential probability model and a Poisson distribution model. The methods for estimating potential maximum earthquake magnitude include four principles：（1）maximum magnitude can be an upper limit magnitude in the same seismic zone and （2）should not be smaller than the largest historical earthquake. （3）It can also be estimated by a relationship, such as M-L and G-R. Moreover, （4）it may have a reference to the maximum mag-nitude in a seismic zone with intensity of VIII degrees during the 200 years since last big earth-quake because the lapsed time is longer than the interval time. The article gives mean maximum magnitudes, which are 7.5,7,7,7, and 6 for the Diebu-Bailongjiang, Guanggaishan-Dieshan, Li-angdang-Jiangluo, Wudu - Kangxian, and Hanan - Qingshanwan - Daoxizi fault zones, respec-tively, with a combination of the four principl

关 键 词：陇南市 地震危险性评估 时间相依 地震潜势概率模型 泊松分布 发震概率 b 值 

分 类 号：P315.5[天文地球—地震学]