中国大陆中强地震序列类型的空间分布特征   总被引：18，自引：2，他引：16       下载免费PDF全文

蒋海昆  李永莉  曲延军  华爱军  代磊  郑建常  侯海峰 《地震学报》2006,28(4):389-398

利用中国大陆1970年以来记录相对完备的294次5.0级以上的地震序列,研究地震序列类型的空间分布特征. 结果表明: 在西南地区,川滇菱形地块及其所控制的鲜水河——安宁河——小江地震带及金沙江——红河地震带以主余型序列活动为主, 滇西和怒江——澜沧江断裂带以西腾冲——保山块体的龙陵、 澜沧等地分布着较多的多震型地震,极少数孤立型地震主要分布于川西北地区,云南地区无孤立型地震. 在西北地区,新疆南天山西段以主余型为主,其中柯坪块体与普昌断裂交汇区发生过多震型地震, 天山中段则以孤立型地震居多;祁连山地震带以主余型序列活动为主;青海地区以主余型地震居多,但序列类型的区域特征不明显. 在华北地区,阴山——燕山——渤海地震带、河北平原地震带及下扬子断块以主余型地震为主, 山西地震带北段与NW向阴山——燕山地震带的交汇部位发生过5～6级多震型地震, 华北地区南部北纬35deg;线附近以孤立型地震居多. 序列类型空间分布与区域构造运动形式有关,断层内部闭锁单元或障碍体的破裂以及新生的、彼此分离的断裂段的破裂,大多产生主余型序列;多震型地震往往与共轭构造或多组构造交汇相联系;简单断层端部的进一步扩展一般产生孤立型地震. 序列类型空间分布与区域深部介质环境也有一定关系,主余型地震大多发生在上地壳高速区或高、 低速过渡带内, 而多震型地震则较多地发生在上地壳低速区内.    相似文献   

2006年7月4日文安5.1级地震   总被引：11，自引：1，他引：10       下载免费PDF全文

刁桂苓  张四昌  孙佩卿  张跃刚  高景春  毛国良 《地震地质》2006,28(3):497-502

分析了震动京津的文安地震的特点:余震微小,最大仅1.5级,属于孤立型地震;震区烈度偏低、有感范围大;宏观震中与微观震中相差10余公里;震源较深;具有较大的正断层错动分量。对此作出初步解释,并认为可能是岩石圈减薄的新证据  相似文献   

Analysis of VIV for Barrel-Shaped Mast with Covering Ice by HPD-S Method     

张营川  马骏  赵德有 《海洋工程》2009,(4):763-768

The vortex-induced vibrations (VIV) of barrel-shaped mast are calculated by three numerical methods, i.e. Newmark-b, HPD-L (High Precision Direct integration scheme-Linear form), and HPD-S (High Precision Direct integration scheme-Sinusoidal form). According to the measured value, the accuracy curves are given to show the advantages of HPD-S method over others. Based on the comparison above, HPD-S method is used to calculate the influence of ice covering on the mast to VIV responses. It has been proved that the vortex-induced responses of barrel-shaped mast are changed along with ice thicknesses and types.  相似文献   

Tensile Fractures and in situ Stress Measurement Data Constraints on Cretaceous–Present Tectonic Stress Field Evolution of the Tanlu Fault Zone in Shandong Province, North China Craton          下载免费PDF全文

YANG Chengwei  WANG Chenghu 《《地质学报》英文版》2023,97(6):1616-1624

Tectonic stress fields are the key drivers of tectonic events and the evolution of regional structures. The tectonic stress field evolution of the Tanlu fault zone in Shandong Province, located in the east of the North China Craton (NCC), may have preserved records of the NCC’s tectonic history. Borehole television survey and hydraulic fracturing were conducted to analyze the paleo and present tectonic stress fields. Three groups of tensile fractures were identified via borehole television, their azimuths being NNW–SSE, NW–SE and NE–SW, representing multiple stages of tectonic events. Hydraulic fracturing data indicates that the study region is experiencing NEE–SWW-oriented compression and nearly-N–S-oriented extension, in accordance with strike-slip and compression. Since the Cretaceous, the orientation of the extensional stress has evolved counterclockwise and sequentially from nearly-NW–SE-oriented to NE–SW-oriented and even nearly N–S-oriented, the stress state having transitioned from strike-slip-extension to strike-slip-compression, in association with the rotating and oblique subduction of the Pacific Plate beneath the NCC, with the participation of the Indian Plate.  相似文献