蒙特卡洛方法与逆冲构造变形速率的限定  

Deformation rate in a compressional tectonic setting derived from Monte Carlo simulation

作　　者：逄立臣 姜禹彤 武登云 吴孟韩 吕红华[1] 郑祥民[1] PANG Lichen;JIANG Yutong;WU Dengyun;WU Menghan;LÜ Honghua;ZHENG Xiangmin(School of Geographic Sciences,East China Normal University,Shanghai 200241;State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029)

机构地区：[1]华东师范大学地理科学学院,上海200241 [2]中国地震局地质研究所地震动力学国家重点实验室,北京100029

出　　处：《第四纪研究》2022年第3期911-920,共10页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:42071005和41771013)资助。

摘　　要：变形速率是衡量构造活动强弱的重要参数,对其准确限定一直是构造地貌、活动构造研究的重点。以河流地貌作为参考面限定构造变形速率是目前研究中最常用的手段。基于近年来的研究体会和具体的研究案例分析认为,虽然目前已能获得可靠的变形量和地貌年龄数据,但若想获得合理、可靠的变形速率,需要关注这两类数据之间的匹配关系与由其构建的断裂滑动历史的合理性。相较于通过位错量与构造变形时间的比值,或利用两者进行线性回归的方法来限定变形速率,从模拟合理的断裂滑动历史的角度出发,蒙特卡洛方法可有效减小变形速率估计的不确定性,使变形速率估计更加合理,从而为地震风险评价等提供可靠的基础资料。Deformation rate is an important parameter to constrain the strength of tectonic activity.An accurate and reliable constraint is one of the main aims of tectonic geomorphology and active tectonics research.In this paper,taking river terrace as the reference,the vertical slip rates of the Hutubi Fault in the northern piedmont of the Tianshan Mountains and the Minle-Damaying Fault in the northern piedmont of the Qilian Shan in the Tibet Plateau are redefined by the Monte Carlo simulation.The results show that the Holocene slip rates of the Hutubi Fault and the Minle-Damaying Fault are 0.39+0.04/-0.03mm/a and 0.9+0.08/-0.07mm/a,respectively.Based on the ratio of the amount and timing of deformation,the slip rate of the Hutubi Fault is determined to 0.34~0.40mm/a.By a linear regression method using the amount and timing of deformation,the slip rate of the Minle-Damaying Fault is estimated to 0.9±0.2mm/a.These above rates show that the Monte Carlo simulation method can give a better constraint on the deformation rate.Today,the high-precision topography is available and the dating method has been significantly improved.These progresses are helpful for better constraining the rate of deformation.If a reliable deformation rate can be obtained,the matching relationship between the deformation amount and age of the fault needs be paid attention to.From the perspective of simulating a reasonable fault slip history,the Monte Carlo simulation can make the estimation of the deformation rate more accurate,which can provide more useful foundational information for the seismic risk assessment.

关 键 词：变形速率 蒙特卡洛模拟 活动构造 晚第四纪 

分 类 号：P546[天文地球—构造地质学] P554[天文地球—地质学]