摘要
2013年9月24日巴基斯坦中南部发生MW7.7地震,震中位于巴基斯坦阿瓦兰县北部69km处,发震断层为走滑断层机制,极震区烈度达到Ⅸ度以上。我们计算了巴基斯坦地震的视应力、应力降等震源参数,明确该地震为断层动态摩擦过程中的应力上调模式;进一步选取发震断层面上滑动位移的反演结果,构建有限断层模型,对近断层区域的强地面运动进行估算,并基于强地面运动模拟结果给出震区的烈度分布图。结果显示,模拟的巴基斯坦地震烈度图极震区烈度达到Ⅸ度,Ⅶ度烈度影响范围与美国地质调查局震后给出的震动图(ShakeMap)较为一致。强烈地震发生后,基于强地面运动模拟计算给出的烈度分布情况具备较好的合理性,对震区给出及时的震情判定和开展相应的救灾工作具有较高的实际价值。
The 24 September, 2013 MwT. 7 earthquake occurred in soutb central Pakistan as the result of strike-slip at the shallow crustal depth of 25 km. This event occurred with- in the transition zone between northward subduction of the Arabia plate beneath the Eura- sia plate and northward collision of the India plate with the Eurasia plate. The location of Pakistan earthquake is 69 km to north of Awaran, Pakistan. The maximum intensity is up to IX in the near-fault field shown in the ShakeMap of the USGS. In this study, we ana- lyze the dynamic source process with the source mechanism, select the effect of slip distri- bution on the fault plane based on two models. One finite fault source model is constructed and we calculate the strong ground motion including acceleration and velocity. Based on the simulated results of the near-fault strong ground motion, we describe the intensity distribution of the Pakistan earthquake. The simulated intensity indicates that the maximum intensity value is IX and region with and above is consistence with the ShakeMap of USGS. In fact, numerical modeling developed in this study has great application in the strong ground motion prediction and intensity estimation for earthquake rescue purpose.
出处
《地震》
CSCD
北大核心
2014年第4期12-19,共8页
Earthquake
基金
国家科技支撑计划项目(2012BAK19B02-01)
中国地震局监测预报司震情跟踪合同制定向工作任务(2014020412)
中国地震台网中心青年科技基金(QNJJPZ-YBB-1307)联合资助
关键词
巴基斯坦Mw7.7地震
视应力
有限断层模型
模拟烈度分布
Finite fault source model
Simulated intensity distribution
Apparent stress
Pakistan MwT. 7 earthquake
