共查询到20条相似文献，搜索用时 546 毫秒
1.
Wang Shuang-xu Jiang Zai-sen Chen Wen-sheng Zhang Xi Chen Bing Zhang Si-xin Wang Ji-ying 《地震学报(英文版)》2001,14(2):156-165
The time-space distribution characteristics of fault deformation anomaly in the near-source region and its outlying zone in
the seismogenic process of the Jingtai M
s=5.9 earthquake occurred on June 6, 2000 in Gansu Province is studied preliminarily. The distribution scope of fault deformation
anomaly before the earthquake is wide, the anomaly shape is complicated and the pattern anomalous zone of fault deformation
(strain) information index is obvious. The shape and amplitude of fault deformation anomaly in different regions differ significantly,
which is closely related with the tectonic location of anomaly. The fault deformation anomaly of α, β, and γ phases along
the western segment of Haiyuan fault zone shows the process from the quasi-linearity to non-linearity of fault movement in
the near-source region, matches the high-value anomalous area of fault deformation (strain) information index, and reflects
the high strain accumulation in the seismogenic region. However, the anomaly of abrupt jump and cusp with a large amplitude
occurred in the areas far from the earthquake, such as Liupanshan fault zone which is the tectonic convergent section does
not reflect the strain accumulation of its location, maybe it is a sign that the regional tectonic stress field is strengthened
in the seismogenic process. Based on the above-mentioned facts and combined with the preliminary summary of experiences and
lessons in the intermediate and short-term prediction of the Jingtai M
s=5.9 earthquake, we study and explore the application of fault deformation anomaly to earthquake judgment.
Foundation item: National Key Basic Research Development Program (G1998040703 and G1998040705), and State Scientific and Technological Project
of the “Ninth Five-Year Plan” (96-913-09-01-02-03 and 96-913-09-02-02-03), China. 相似文献
2.
Following a new train of thinking, this paper has explored first the potential information in the ground resistivity data observed by the existing geoelectric observation system, investigated and proposed a new dimensionless geoelectric precursor factor, the degree of ground resistivity anisotropy, S, and studied the characteristics of dynamic evolution pattern of S during the seismogenic process. The results show that, during the seismogenic process, the degree of ground resistivity anisotropy (S) displays a process of 'normal' →'abnormal strengthening (amplitude, range)' →abnormal weakening' → 'earthquake occurrence'→ 'normal'. The earthquake would occur at the time when the S value has entered the late stage of strengthening and turns to weaken and in the gradient belt on the margin of S anomaly region. The dynamic evolution pattern of S reflects the changes of the tectonic stress field during the seismogenic process. Therefore, it would be possible to trace the process of earthquake generation and occurrence from the dynamic evolution pattern of S so as to service earthquake prediction. 相似文献
3.
初步研究了2000年6月6日甘肃景泰5.9级地震蕴育过程中近源区及外围地区断层形变异常的时空分布特征:震前断层形变异常分布范围广、异常形态复杂，断层形变（应变）类信息指标图象异常区明显．不同地域断层形变异常形态及幅度存在显著差异，与异常所处的构造部位密切相关:海原断裂带西段出现的，，相断层形变异常，显示了近源区断层运动由准线性走向非线性的过程，与断层形变（应变）类信息指标高值异常区相配合，反映蕴震区应变积累程度高；而构造汇聚部位的六盘山断裂带等远场区较大幅度的突跳尖点异常，并不反映所在地的应变积累，而可能是蕴震过程区域构造应力场增强的一个标志．在此基础上，结合对景泰5.9级地震中短期预报经验教训的初步总结，研究和探讨了断层形变异常在震情判定中的应用． 相似文献
4.
Fault deformation anomaly and intermediate and short-term prediction of the Jingtai M_s=5.9 earthquake 总被引：1，自引：0，他引：1
IntroductionOn June 6, 2000, an earthquake of MS=5.9 occurred in Jingtai county, Gansu Province. The epicenter (37.1(N, 104.0(E) was located in Maomaoshan-Laohushan zone of the western segment of Liupanshan-Haiyuan fault along the northeastern margin of Qinghai-Xizang Plateau, where is the middle-eastern part of crustal deformation monitoring area of Gansu-Ningxia- Qinghai region. There are more than 50 spanning-fault mobile monitoring sites in the earthquake area and its vicinity (Fig… 相似文献
5.
利用南北地震带及附近地区２０ 多年来的大地垂直形变资料, 结合区域地震活动资料, 初步分析归纳了大地形变时空分布与地震群体活动的关系。在此基础上, 进一步对南北地震带中南段之川滇菱形块体形变场中期动态演化图象与ｂ 值等地震活动参数图象进行了综合对比分析, 研究了形变场动态演化所揭示的区域现今构造运动的时空差异与反映地壳介质结构特性的ｂ 值的时空分布变化、强震前后地震非均匀度值分布变化以及地震空区等的关系。结果表明： 强震前区域形变场动态演化与地震活动参数的时空分布均具有一定的非均匀特征, 二者所反映的大区域应力场变化与介质结构的不均匀导致的强烈差异运动产生的应变能积累是强震孕育的主要原因。得出了一些利用大地形变场动态演化与地震活动参数图象相结合进行强震中期预测的有益结果。 相似文献
6.
强震中期阶段区域性形变异常的共性特征及其机制以青藏块体东北部为例 总被引：2，自引：1，他引：1
强震前中期阶段(1～3年或稍长)区域性形变异常往往表现出3个方面的共性特征: ① 区域垂直运动变形呈现与构造有关的异常隆起区、 垂直差异变形高梯度带(有的还呈“四象限”)分布特征; ② 水平运动变形呈现与活动地块及断裂构造有关的、 以剪切变形为主的高应变集中区(带)特征; ③ 区域性垂直形变异常区与水平形变的高应变分布区共生的特征。 分析这些异常共性特征的形成机制, 初步认为: 它们是在基本统一的大区域构造应力场控制下, 不同层次块体系统运动及其边界带变形的非平稳、 非协调性, 在活动地块边界地带和地块内部次级断裂构造部位产生变形差异而导致应力-应变积累、 孕育强震到一定阶段的结果。 在此基础上, 分析探讨了基于区域性形变异常共性特征、 结合地质构造活动背景进行强震中期预测的意义。 相似文献
7.
Study on the pattern and mode of vertical crustal deformation during the seismogenic process of intraplate strong earthquakes 总被引：3，自引：0，他引：3
Ｓｔｕｄｙｏｎｔｈｅｐａｔｔｅｒｎａｎｄｍｏｄｅｏｆｖｅｒｔｉｃａｌｃｒｕｓｔａｌｄｅｆｏｒｍａｔｉｏｎｄｕｒｉｎｇｔｈｅｓｅｉｓｍｏｇｅｎｉｃｐｒｏｃｅｓｓｏｆｉｎｔｒａｐｌａｔｅｓｔｒｏｎｇｅａｒｔｈｑｕａｋｅｓ杨国华，桂昆长，巩曰沐，杨春花，韩... 相似文献
8.
In this paper, the fault deformation abnormality, dynamic evolution features of gravity and vertical deformation field in
the seismogenic process of the Yongdeng, Gansu Province earthquake on July 22, 1995 are studied primarily. There appeared
α-β-γ tri-stage anomaly at three sites near the epicenter, and there appeared anomalies of step and sudden jump at more than
10 sites in outer region since 1993. The high value area before shock, coseismic effect and process of recovery aftershock
were monitored by portable gravity data. Data reflects the changing process of fault movement from the quasi-linear to the
nonlinear in the near source region during seismogenic development of the Yongdeng earthquake and evolution of gravity field
from heterogeneity of seismogenic term to quasi-homogeneity of postseismic term. There exists close relationship between strong
earthquake and dynamic evolution of regional stress-strain field. Considering all above, the experience and lessons in this
medium-short term prediction test are summarized. 相似文献
9.
Using the tendentious accumulation rate of crustal deformation,DC,the spatial distributionfeatures of deformation across fault in the West of China was studied;the regional patterns ofdeformation accumulation induced by fault activity was established and its seismogenicmeaning was discussed.The types of fault deformation evolution in the time domain and thefeatures of change of large extent anomaly in fault deformation which occurred in 1995～1996was analyzed comprehensively.It was indicated definitely that 1995～1996 is the turningpoint of fault network activity in the West of China since the 1990s;it is closely related to thechange of main seismic active regions in the West of China,i.e,the alternation of strong/weak stages and the change of action range of tectonic stress field in the Qinghai-Tibet blockand its environs;and hence it is of medium-and short-term precursor meaning for the changeof the overall pattern of earthquake activity in the West of China in the year 1996.On such abasis,a preliminar 相似文献
10.
Based on the studies of earthquake activity, tectonic movement, crustal shortening rate, fault activity, local stress field and historical characteristics of strong earthquake activities in Xinjiang, we divide the south part of Xinjiang into 4 seismotectonic zones, namely, the eastern segment of south Tianshan seismic belt, the Kalpin block, the Kashi-Wuqia junction zone, and the west Kunlun Mountains seismic belt. Using earthquake catalogues from Xinjiang since 1900, and on the basis of integrity analysis of earthquake records in different magnitude ranges, the seismicity state of different seismotectonic zones is analyzed quantificationally by calculating the mean value of annual strain energy release, annual rate of earthquakes with different lower limits of magnitude, b-value, and the parameter m of accelerating strain release model. The characteristic indexes of seismicity state for each of the seismic tectonic zones are then determined, which provide a quantitative basis for earthquake tendency analysis and judgment. 相似文献
11.
Shi-Rong Mei 《地震学报(英文版)》1996,9(1):1-12
In this paper, the stress concentration process and the time-space distribution of stress when earthquakes are in preparation
in one or more earthquake-generating bodies in a tectonic block have been analyzed and their relation with seismicity and
earthquake precursors have been studied. The results show that: 1 When the regional stress field has intensified to a certain
level, fracture begins in some block or blocks. The regional stress field will vary with time and the occurrence of strong
earthquakes in groups is the result of the evolution of this dynamic stress field. In this process, the existence and development
of more than one high stress concentration zone may give rise to a variety of pre-seismic anomaly-to-earthquake relations.
2 The process of stress variation in an earthquake-generating block generally appears as a nonlinear one. After the long-term
elastic deformation, there may be more than one time of inelastic deformation and fault-softening from the beginning of the
stage of inelastic deformation to just before the main fracture. Corresponding to such a nonlinearity, the stress and strain
fields in the earthquake-generating block will display a complex pattern of time-space evolution; and thus the earthquake
precursor fields controlled by stress and strain must display complexities in many aspects. 相似文献
12.
华北北部地区的张家口-渤海断裂带是控制现代强震的一条地震构造带。新近纪以来,在区域NEE向主压应力的作用下,新发育了一系列的NE向构造活动带,与张家口-渤海断裂带组成1组共轭的剪切破裂系统,控制了近代强震的发生。文中主要探讨了这条断裂带的地壳形变特征。长趋势GPS地壳形变图像反映了这条活动断裂带相对完整的左旋走滑活动。分期的地壳形变图像揭示了在中强地震前,沿该断裂带出现一系列的NE向梯度异常带,分别指示了唐山-河间、三河-涞水以及延怀-山西地震构造活动带的活动,表明了沿张家口-渤海断裂带出现了中强地震的中期前兆。研究认为,强震前地壳形变揭示的是深部蕴震层的应变活动信息,而强震之后比较杂乱的图像特征体现了盖层的调整运动 相似文献
13.
昆仑Ms 8.1地震前青藏块体北、东缘水平运动变形的关联特征 总被引：2，自引：0，他引：2
青藏块体东北缘和川滇GPS监测区1991(1993)、1999和2001年高精度GPS观测资料揭示：2001年11月14日昆仑Ms8．1地震前，青藏块体北、东缘构造区域水平运动变形场动态演变具有一定的关联性特征。即：在继承性运动总体背景下，临近大震发生时两区域运动强度同步减弱且变形状态发生变化。结合地质构造分析研究认为，昆仑Ms8．1地震前，青藏块体边界运动变形的关联性变化与大震孕育后期大范围应力应变快速积累所形成的扰动应力场有关；随着块体内部大震的发生、应变能的大量释放和构造应力场的调整，可能会促使块体边界地带具有较高应变积累的相关构造部位(尤其是未被历史强震破裂贯通的地带)的应力应变的进一步积累或破裂释放。 相似文献
14.
15.
Unstable fault deformation and information synthesis 总被引：2，自引：0，他引：2
ＵｎｓｔａｂｌｅｆａｕｌｔｄｅｆｏｒｍａｔｉｏｎａｎｄｉｎｆｏｒｍａｔｉｏｎｓｙｎｔｈｅｓｉｓＷＡＮ－ＪＵＢＯ（薄万举），ＪＵＥ－ＭＩＮＸＩＥ（谢觉民）ａｎｄＧＵＡＮ－ＳＨＯＵＬＯＵ（楼关寿）ＦｉｒｓｔＣｒｕｓｔａｌＤｅｆｏｒｍａｔｉｏｎＭｏｎｉｔ... 相似文献
16.
应用山东省和江苏省地震局“九五”地质研究成果, 在华东地区共选择49条断裂和7个构造块体作为地震活动性研究的构造基础, 选用频度、 ΔT-T、 小震调制比3个参数, 对构造两侧各20 km宽度范围的地震资料进行参数时间扫描。 通过普查, 得到的构造优势映震距离为300 km; 得到了10个敏感构造及其映震特点。 通过对华东地区13个中强地震震例的构造异常的综合分析, 得到如下认识: ① 震前存在场的群体异常特征, 表明华东中强地震“前兆”是在构造应力作用下表现出的、 区域性的整体过程; ② 异常的构造常常分布在震中周围; ③ 地震常常发生在平静异常的构造附近; ④ 高频度异常常常发生在震中外围, 并常具有步进性; ⑤ 震中周围的构造在震前2～3年开始先后不断出现高频和平静异常, 平静后出现多处小震调制比高值是孕震中期向短期过渡的时间转折标志。 相似文献
17.
汾渭断陷带现今垂直形变与近期地震活动性 总被引：1，自引：0，他引：1
本文针对2008年汶川地震后鄂尔多斯块体周缘出现的小震活跃现象, 利用分布于汾渭断陷带不同部位的跨断裂水准资料, 分析了其近期的垂直形变演化过程。 结果表明: ① 各水准剖面的垂直差异运动幅度基本稳定在±20 mm之间, 且在小震活动期间未出现明显的形变异常; ② 鄂尔多斯块体周缘近期小震活跃可能是缘于汶川地震后, 青藏块体挤压应力减弱, 华北块体对其推挤作用相对增强而造成鄂尔多斯块体的水平挤压应力场的“暂态失稳”所致。 相似文献
18.
首先, 利用“中国地壳运动观测网络”和“中国构造环境观测网络”截至2013年的GPS区域站观测资料, 结合地质构造, 简要分析了2014年2月12日新疆于田7.3级地震前大区域地壳水平运动变形背景; 接着, 对青藏块体东北缘地区GPS和精密水准两种不同类型资料反映的地壳运动变形与应变积累状态进行了对比分析研究; 最后, 结合地震活动动力环境, 研究和探讨了于田7.3级地震的发生对青藏块体东北缘地震活动的可能影响。 我们认为, 此次于田7.3级地震发生在近年来中国西部边邻强构造活动环境和内陆地壳强烈差异运动显著的背景下, 同时也是青藏块体及其边缘构造应力场较强的时段; 于田7.3级地震左旋走滑错动和应力传递, 可能会加速青藏块体东北缘具有高应变积累的构造断裂部位(尤其是祁连山构造带、 西秦岭以南的甘青川交界)破裂释放。 相似文献
19.
云南强震活动的多层次动力源分析 总被引：2，自引：2，他引：2
对云南地区多层次动力过程作了分析研究，结果表明，若以两大板块之间在边界上的相互作用为最高层次的动力作用，云南地区现代构造运动至少包括三个层次的动力作用过程：(1)印度板块和亚欧板块两大地壳板块在喜马拉雅碰撞带东部弧顶和东翼相互作用产生的边界动力源对云南地区产生的直接影响和间接作用；还有菲律宾海板块对亚欧板块的北西西向的推挤，通过华南地区对云南东部的间接作用，构成了云南地区现代构造运动第一层次动力作用；(2)以康滇菱形断块为主体，包括川青断块、滇西南断块带等板内断块的整体向南南东—南东方向的相对移动产生的动力作用，是第二层次的动力作用；(3)由于板内断块边界断裂运动速率的差异，主要是水平滑动速率差异造成的板内断块内部次级断块移动产生的动力作用，是第三层次的动力作用。对印度板块和亚欧板块两大地壳板块碰撞挤压带东部弧顶和东翼相互作用产生的边界动力源与云南及邻区构造运动、构造应力场分布格局和强震活动关系作了分析研究，认为云南及邻区多层次动力作用过程，是强震活动时空分布的主要原因。 相似文献
20.
IntroductionChinesemainlandliesinthesoutheastofEurasianPlateandisclampedbyindian,PacificandPhilippineSeaPlates.Besides,itislocatedatbetweenthetwobigseismicactivebeltsintheworldatthesametime.Differingfromtheshowoftwobigseismicbeltswhichhaveseismiczonaldistributionalongplateboundary,Chinesemainlandanditsperipheralareahaveapeculiarcharacter,expressingseismicallylargestrength,highfrequency,widedistribution,shallowfocus,seriousdamage,multiplestyles,extremelynonuniformspace-timedistributionandsoo… 相似文献