共查询到18条相似文献,搜索用时 78 毫秒
1.
“十五”期间即将实施20个省会级城市的活断层探测与地震危险性评价工程。文中对该工程的技术指导性文件“城市活断层探测与地震危险性评价工作大纲(试行)”的基本内容和领会要点进行了阐述。对“工作大纲”的5大属性(科学性、普适性、包容性、可操作性、约束性)作了说明,对探测工程的主要对象活断层和地震活断层进行了界定,对工作区和目标区的内涵及工作途径的差别做了解释。分析了工程所面对的3个层次的科学问题和实施过程中的5个步骤,并对每个步骤中需要注意的事项和应采取的对策分别进行了探讨。文章阐述了探测过程中安排中期验收的必要性,指出本工程是以往各震害防御工作的延续、发展与深入 相似文献
2.
3.
4.
断层逸出气体的δHe/Ar值变化与地震活动的关系 总被引:3,自引:0,他引:3
论述了1990年6月底至1991年12月间塔院断层气体中δHe/Ar值变化与几次地震的关系,从已获得的几次震例来看,有的地震δHe/Ar出现负异常,而有的出现正异常。δHe/Ar值具有较好的映震能力。 相似文献
5.
河北磁县西部北西西向南山村-岔口活动断裂为北西西向磁县活动断裂西段,全长35km,又可再分为东西两段。全新世时期该断裂有多次活动,活动方式以具左旋性质的正倾滑为主。1830年磁县7.5级地震时,南山村-岔口断裂带出现新的地表破裂,地表垂直位移多处为2~4m,最大约7m。据目前资料,该断裂带最新两次地震事件的时间间隔约为3500a。最近获取的位于磁县最高峰老爷山庙宇碑文资料,补充说明了邻近岔口活动断裂带的古建筑物在1830年地震中的严重破坏 相似文献
6.
7.
河北磁县西部北西西向南山村-岔口活动断裂为北西西向磁县活动断裂西段,全长35km,又可再分为东西两段。全新世时期该断裂有多次活动,活动方式以具左旋性质的正倾滑为主。1830年磁县7.5级地震时,南山村-岔口断裂带出现新的地表破裂,地表垂直位移多处为2~4m,最大约7m。据目前资料,该断裂带最新两次地震事件的时间间隔约为3500a。最近获取的位于磁县最高峰老爷山庙宇碑文资料,补充说明了邻近岔口活动断裂带的古建筑物在1830年地震中的严重破坏。 相似文献
8.
基于不同类型活断层产生的地震地表破裂带宽度和跨断层探槽地质剖面的地层强变形带宽度等观测事实 ,结合地面建筑设施毁坏带与活断层密切的空间位置关系 ,采用统计分析方法 ,确定了活断层“避让带”宽度为 30m。各活断层更为准确的避让带宽度可通过分析跨断层探槽地质剖面上地层的变形特征加以验证或修订 ;活断层斜列阶区、平行次级断层围限区、走向弯曲区等特殊地域的避让带宽度为这些地域宽度与两外侧各 15m之和。建议有关部门进行活断层“避让带”立法与执法管理 ,并加强活断层鉴定及其地表活动线几何结构形态的准确定位工作 ,积极而有效地减轻地震灾害 相似文献
9.
11.
12.
13.
海阳断裂是胶东半岛NE向牟平 -即墨断裂带东部一条规模较大的断裂 ,尽管晚更新世以来该断裂的地表断错活动总体上已基本停息 ,但东石兰沟段在晚更新世晚期以来仍有断错地表的活动。最后一次断错地表的活动发生在距今 3 7~ 1 2万年 ,但接近 1 2万年。地表破裂长度约6 5km ,活动段长度 8km。地表断错以走滑活动为主 ,可见最大倾滑位移 0 2m ;根据断层擦痕侧伏角推测最大水平位移 1 13m。最后一次断错地表的活动若以距今 1 2万年计算 ,则最大平均倾滑速率为 0 0 17mm/a ;最大平均右旋走滑速率为 0 0 94mm/a。野外观测到该活动段的断错活动表现为突发断错 ,根据地震地表破裂参数、活动段长度与地震的关系 ,估计其最大潜在地震为 6 级 相似文献
14.
15.
To establish an experimental, practical and open scientific experimental platform for earthquake monitoring and prediction, with reference to that of the southern California earthquake center(SCEC), China Earthquake Administration initiated a project for an experimental field in Sichuan and Yunnan Province in 2014. The chosen area is a seismically active region in the southeastern margin of the Tibetan plateau. A series of work compiling basic maps have been launched to collect fundamental data of this area including geologic structure, earthquake geology, geophysics, geodesy, and geochemistry. The map of earthquake surface ruptures in this region is one of these basic maps. This paper presents the compilation of this map. It includes earthquake epicenters, earthquake surface ruptures, faults, strata, magmatic rocks, and geographical data. This work summarized 87 destructive earthquakes, and 22 earthquake surface rupture zones, and analyzed the distribution characterization of earthquake epicenters, strata and magmatic rocks. The content in the map is reliable and integrated. This work will provide reliable earthquake-geology data for establishing geodynamics models and other future research of the national experimental field of earthquake monitoring and prediction in Sichuan and Yunnan Province. 相似文献
16.
17.
MICROSTRUCTURAL FEATURES AND IMPLICATIONS OF FAULT GOUGE FROM THE FAULTS OF BEDROCK REGION IN THE CENTRAL-NORTHERN JIANGXI PROVINCE,CHINA 下载免费PDF全文
How to survey fault activity and determine seismogenic structures in a relatively stable and bedrock-distributed region is a challenging research work. Ruichang-Tonggu Fault and Yifeng-Jingdezhen Fault, distributed mainly at the pre-Cenozoic bedrock region, show the geological evidences of activity in the Quaternary and they are two important tectonic belts for the occurrence of moderate earthquakes in the central-northern Jiangxi Province. Fault gouge stripes can be found on the outcrop sections of the two faults. The imageries of the microstructures of fault gouge show abundant phenomena about the structural deformation, and it is clear that the fault gouge was formed by structural activity. As to the deformation modes, there are not only the Y-shears and R1-shears, which represent the localized-brittle deformation, but also the P-foliations, which reflect the ductile deformation in the microstructures of fault gouge. These features demonstrate that the micro-scale rapid deformation can exist in the seismogenic structure at the near-surface in the occurrence process of moderate earthquakes very possibly. The microstructures of soft material from the fault outcrop section at the southern segment of Hukou-Xingan Fault, which is inactive in the Quaternary, reflects that the soft material from the fault zone can also be the products of rainwater leaching and filling, or weathering in the later periods. Based on the macroscopic observation in the field, it is sometimes difficult to distinguish the differences of structurally-formed or non-structurally formed soft gunk in the fault zones, however, their differences in the microstructure on the slices grinded indoor are obvious. The relatively stable bedrock areas in South China often are not only favorable for the siting of major projects, such as nuclear power plant in China, but also the economically-developed, densely populated, urban agglomeration areas. The study of microstructure of fault gouge provides a technical reference approach for the identification of fault activity and the determination of seismogenic structure of moderate-strong earthquakes in assessing the seismotectonic environment in these regions. 相似文献