黏滑实验的震级评估和应力降分析   总被引：2，自引：0，他引：2       下载免费PDF全文

郭玲莉  刘力强  马瑾 《地球物理学报》2014,57(3):867-876

本文通过三种结构模型的黏滑地震模拟实验,利用高频速度连续观测系统获得了地震失稳过程的速度特征,讨论了最大位移量的选取方法,估算了实验室黏滑型地震的矩震级,探讨了黏滑类型、应力降大小与震级的关系.结果表明,黏滑型地震的应力降过程可能包含一次到多次高频振荡,对应若干次黏滑子事件.高频振荡的摆动幅度很大,包含有多种频率成分,峰值速度0.003~0.008 m·s^-1.初步估计黏滑型地震的震级范围为-4.4~-3级,断层构造面的差异对各种黏滑模型的地震震级分布有明显影响.总体来看应力降与地震震级没有明显相关性,决定地震震级的主要因素应当是震源尺度.  相似文献   

基于择优的块体模型解算南北地震带中南段主要断层滑动速率     

闫伟 《中国地震研究》2014,28(1):62-72

In this paper, using the 1999 ~ 2007 GPS velocity field data, and by choosing the optimal block model, we obtained the deformation models applicable to the boundary zones of major blocks and the slip rates of block boundary faults on the mid-southern segment of the North-South Seismic Belt. The results show that： on the Longmenshan fault zone, the tensional and compressive slip rate is small on the Baoxing-Wenchuan segment, about 0. 5 ~ 1.8mm·a^-1, and the rate is relatively significant on the segment of the Wenchuan--Maoxian, as 1.8 ~3.8mm·a^-1; on the Xianshuihe fault belt, there is a certain difference in spatial distribution between the tensional slip rag.e and strike-slip rate： the tensional slip rate （ 8. lmm~a-1） is bigger than the sinistral strike-slip rate （ 4.8mm·a^-1） at the north of the Luhuo region; the tension and compression slip rate is basically the same as the strike-slip rate at Luhuo-Dawu; the Dawu-Kangding section presents a trend of decreased strike-slip rate and increased tensional slip rate; the Kangding-ghimian segment shows a strike-slip nature; the strike-slip rate is significantly greater than the tension/compression rate on the Xiaojiang fault zone; the slip rate on the Red River fault zone shows obvious spatial segmentation, the slip rate is smaller in its northwest part, but with a certain amount of tensional/compression component, 4. 7mm·a^-1 on the Jingdong segment. The segment east of Jingdong （ western Gejiu） is mainly of strike-slip, with a slip rate of 4. 5mm·a^-1.  相似文献   

五台山北麓断裂繁峙段晚第四纪活动性研究     

赵仕亮  谭锡斌  于贵华  徐锡伟  石峰  孙鑫喆  高伟 《震灾防御技术》2016,11(4):722-735

五台山北麓断裂位于山西地堑系北部。本文以五台山北麓断裂繁峙段的地质地貌为研究对象,分别在繁峙县的大峪村和岗里村两地断裂沿线进行了无人机测量。利用三维结构的运动重建技术(Structure from Motion,SfM)进行影像数据处理,得到高精度点云数据,并通过进一步处理获得了分辨率达0.5m的高清断错地貌正射影像(DOM)和数字高程模型(DEM)。通过对典型地区的详细野外调查和挖掘探槽等手段对该段晚第四纪的活动性进行研究,发现断层晚第四纪以来的活动主要是以正倾滑运动为主。同时在五台山北麓断裂沿线的大峪村、岗里村等地进行了断错地貌分析和晚第四纪滑动速率计算,得到约20ka以来的断层垂向滑动速率为0.4—0.6mm/a,近18ka以来该段发生过至少两次古地震事件。古地震事件和滑动速率分析表明,五台山北麓断裂晚第四纪,尤其是全新世以来活动强烈,且不同段落存在明显的活动性差异。  相似文献   

宁波抽水蓄能电站上库滑塌体稳定性分析     

Zhang Faming 《地球科学与环境学报》1997,(3)

宁波抽水蓄能电站上库右岸距坝线８０～１３０ｍ为一滑塌体组成的岸坡，滑塌体的稳定与否将影响发电引水隧洞位置的选择。通过对该滑塌体的变形特征分析和稳定性计算，得出该滑塌体在动水压力作用下将处于不稳定状态的结论。  相似文献   

Study on Active Faults and Seismogenic Structure for the 1989 Batang M6.2 ～ 6.7 Earthquake Swarm in the Litang-Batang Region of West Sichuan, China     

Zhou Rongjun 《中国地震研究》2005,19(3):292-305

INTRODUCTIONGeological investigations since the1970s have shown that the sub_longitudinal Jinshajiang andHonghe(Red River)fault zones constitutethe western boundary of“Rhombic Sichuan_Yunnan Block”onthe Sichuan_Tibet border and display mainly dextral sh…  相似文献   

Seismic characteristics and kinematic models of Makkah and central Red Sea regions     

Mashael M. Al-Saud 《Arabian Journal of Geosciences》2008,1(1):49-61

Makkah and central Red Sea regions have been re-evaluated from recent earthquake data analysis. Epicenters of recent seismic activity are concentrated in three local seismic zones. These are Ad Damm fault (NE), Nu’man–Makkah–Fatima (NW), and Jeddah-Red Sea (NW) seismic zones. Moreover, an extended seismic zone along the central part of Red Sea is observed. Most of these epicenters are distributed along tectonic faults, as indicated from the subsurface structure analysis of the aeromagnetic anomaly map. Some epicenters of small magnitudes are inaccurately located. The study indicates the existence of large active structural basin south of Makkah region, which traverse Ad Damm fault zone with the Red Sea transform faults. Slip vector analyses were carried out for 50 available earthquake focal mechanisms around Makkah region. In Nu’man, Makkah, and Fatima structural zones, the slip vectors generally trend NW and NNW. However, in the southern part at the Ad Dam structure zone, the slip vector trends NE–SW. These may result from the current complicated drifting motion of Arabian plate away from African plate combined with the opening of the Red Sea rift.  相似文献   

东昆仑断裂东端塔藏断裂压剪活动与高原隆升作用讨论   总被引：6，自引：0，他引：6  

胡朝忠  任金卫  杨攀新  熊仁伟  陈长云  付俊东 《地质学报》2017,91(7):1401-1415

塔藏断裂位于东昆仑断裂带东端,横贯青藏高原东缘的高原内部和边缘,因属于巴颜喀拉块体向东南运移的东北侧边界带,其晚第四纪活动性质和滑动速率对认识青藏高原的构造变形模式极端重要。本文综合SPOT、中巴资源卫星等高分辨率遥感影像解译,利用冲沟、山脊、断错河流阶地、断层槽谷、反向坎等地震地貌的识别,开展详细的断错地层、地貌研究和系列年代学样品采集测试,对塔藏断裂的精细几何展布、晚第四纪活动性质、滑动速率进行详细分析。塔藏断裂自西向东可分为青藏高原内部的罗叉段、青藏高原边缘的东北村段和马家磨段,各段走向依次为113°、142°、130°,逐渐向南偏转,晚第四纪的活动表现为分段性和多期性。罗叉段全新世以左旋剪切走滑为主兼挤压活动,左旋走滑速率为2.43~2.89mm/a左右,最新地表断错事件发生在0.66±0.04ka BP以来,断层面表现出走滑断层的近垂直和张裂并发育充填楔的典型特征,塔藏断裂为东昆仑断裂系东延的主要断裂之一;马家磨段也为全新世活动断层,距今9.0±0.8ka的地层被断错,而且断层面北倾达58°。因此,对比分析塔藏断裂各段活动特征可见,西部以水平剪切运动为主,而东部走滑运动分量逐渐变弱,断面北倾、北盘上升导致的垂向分量逐渐变大。东昆仑断裂带及塔藏断裂晚第四纪走滑速率向东规则减小,并转化为横向逆冲作用和高原隆升,符合"叠瓦状逆冲转换—有限挤出模型"的特征。  相似文献