Discussion on Deep Tectonic Background of Moderately Strong Earthquake in Anhui Province and Its Nei

来源 :Earthquake Research in China | 被引量 : 0次 | 上传用户:aspnet2002web
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Using the latest results of seismic tomography, we studied the deep tectonic settings of the moderate and strong earthquakes in Anhui Province and its neighboring areas (28°~39°N, 112°~124°E). The results are as follows: (1) There exists a certain correlation between the location of moderate-strong earthquake, the geologic structure of the surface and the partitioning of active tectonic elements with the upper-crust velocity structure. Most earthquakes recording M≥6.0 occur in high-velocity zones or in the transitional areas between high-velocity and low-velocity zones in the upper crust. Seismicity in the low-velocity zone has a lesser impact. Earthquakes occuring in the high-velocity zone are distributed mainly in the velocity variation area. The boundary belts and the interior of the North China plain fault block are the main active sites of moderate-strong earthquakes. Beneath the fault basins in the western and northern sides of the block, the upper crust is characterized by a wide discontinuous distribution in the low-velocity zone, and in the transition zone from the low- to high velocities, the moderate strong seismicity shows a zonal distribution where active faults are developed. The NW-extension Zhoukou-Hefei-Xuancheng low-velocity zone separates the high-velocity zones of Dabieshan Mountains and west Shandong-Anhui, and moderate-strong earthquakes on its northern side bordering the high-velocity zones are relatively frequent. This low-velocity zone is probably an important and deeply structured boundary between the North China and the South China tectonic provinces. (2) The frequent moderate-strong earthquake recorded in the past and the recent small earthquake activities in the Huoshan-Lu’an area are the result of a low-velocity zone in the middle crust beneath the central part of Dabieshan and the two sets of deep faults that cut through the crust.(3) In terms of deep structures, the distribution of moderate-strong earthquake in Anhui Province has an obvious regional feature. Based on historical earthquake recurrence intervals and analogue principles of deep seismogenic tectonics, the potential earthquake risk zones recording M_S5.0 in Anhui Province are determined. Using the latest results of seismic tomography, we studied the deep tectonic settings of the moderate and strong earthquakes in Anhui Province and its neighboring areas (28 ° ~39 ° N, 112 ° ~124 ° E). 1) There exists a certain correlation between the location of moderate-strong earthquake, the geologic structure of the surface and the partitioning of active tectonic elements with the upper-crust velocity structure. Most earthquakes recording M ≧ 6.0 occur in high-velocity zones or in the transitional areas between high-velocity and low-velocity zones in the upper crust. Seismicity in the low-velocity zone has a lesser impact. Earthquakes occuring in the high-velocity zone are distributed mainly in the velocity variation area. The boundary belts and the interior of the North China plain fault block are the main active sites of moderate-strong earthquakes. Beneath the fault basins in the western and northern sides of the block, the upper crust is characterize d by a wide discontinuous distribution in the low-velocity zone, and in the transition zone from the low- to high velocities, the moderate strong seismicity shows a zonal distribution where active faults are developed. The NW-extension Zhoukou-Hefei-Xuancheng low -velocity zone separates the high-velocity zones of Dabieshan Mountains and west Shandong-Anhui, and moderate-strong earthquakes on its northern side bordering the high-velocity zones are more frequent. This low-velocity zone is probably an important and deeply defined boundary between the North China and the South China tectonic provinces. (2) The frequent moderate-strong earthquake recorded in the past and the recent small earthquake activities in the Huoshan-Lu’an area are the result of a low-velocity zone in the middle crust beneath the central part of Dabieshan and the two sets of deep faults that cut through the crust. (3) In terms of deep structures, the distribution of moderate-strong earthquake in Anhui Provinc e has an oBased on historical earthquake recurrence intervals and analogue principles of deep seismogenic tectonics, the potential earthquake risk zones recording M_S5.0 in Anhui Province are determined.
其他文献
四 当我们在深入思考公安工作和公安教育的可持续发展的可行性的时候,是否可以在二者之间寻找出一条切实可行的科学之路呢?笔者认为完全可以。对这个问题,笔者提出这样一种设想,
今年5月,国信寻呼七台河分公司156.150MHz频点在新兴区一带受到干扰,我监测站立即组织人员用HR-5搬移式综合监测系统对干扰地区进行了监听监测。国信寻呼156.150MHz信号为高
活动内容: 人教版九年义务教育六年制数学第三册62-63页“玩一玩,做一做”。活动过程: 师:今天老师与同学们一道来动脑、动手上一节活动课。(电脑演示:学生欢快有趣的活动场
古人曾有“蜀道之难难于上青天”的哀叹,如今走在我省一些农村里,也常常会令人产生同样的感慨。瞧瞧那路上,尽是东一堆西一堆的垃圾,废弃的塑料包装袋随风满地乱卷,还有时不
本文报道常规治疗加用甘草甜素(强力宁)2mL/(kg·d)于5%葡萄糖250mL静滴治疗流行性乙型脑炎38例,男23例,女15例,年龄8mo-7yr,平均3.4±SD1.8yr。治愈好转率95%,而对照组为83%。
面积约65平方米间隔二室一厅千禧年的来临,意味着人类正步入新的时代。虽然将来的世界未可知,但却为人们带来无限联想,这种联想便丰富了思想创作。无边无际的宇宙,总给人深
郑振铎藏残本《红楼梦》的渊源杨传容郑振铎原藏的一种《红楼梦》抄本只残存第二十三、二十四两回,通常亦称作郑藏本或郑本。由于篇幅少,又因为其中有一些不寻常的异文,因而给人
病人男 38岁工人因低热、咳嗽2周,于1990年3月4日门诊。既往无药物过敏史,曾注青、链霉素无不良反应。查T、P、R、BP及肝功正常,ESR 32mm。诊为肺结核(痰菌阴性),予以2SHR/7
司马义·艾买提视察西南民族学院1994年4月9日上午,在四川检查指导工作的国务委员兼国家民委主任司马义·艾买提同志在四川省副省长欧泽高等同志的陪同下,到西南民族学院视察,听取了该
我县分别在1983年、1986年、1989年发生3例类狂犬病性癔病和假性狂犬病患者。今报道于后:例1:夏××,女,61岁,1983年2月14日被同村乡邻养的犬所咬(此犬未曾注射狂犬疫苗),犬