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1.
通过汶川地震震区大量的实地考察已证实沿着早先活动断裂主要发育了两条地表破裂带：一条是沿着映秀－北川断裂产生的逆冲伴随右旋走滑破裂带,长275km,最大垂直位移达11m,水平位移达12m; 另一条纯逆冲性质的破裂带,沿着灌县－安县断裂发育,最大垂直位移达4m。活动断裂之上的地表破裂带是野外工作中确定地震断裂性质的重要现象。另外,在活动断裂相邻区域和远离区域的路面以及建筑体还大量存在变形现象。通常沿活动断裂产生的地表破裂是典型的同震破裂,相邻区域的地表路面及建筑体发育的变形属于次生变形,远离区域发育的变形则属于震后变形。对次生变形和震后变形测量数据的应用容易影响活动断裂特征的确定和性质的判断,因为路面等建筑体上的挤压拱起、叠置以及水平错断等现象多是受到地震过程中通过断裂活动突然释放的巨大能量作用在局部地表建筑体产生的变形。但是,分布广泛的挤压现象暗示了区域上挤压应力场环境,有利于地表同震破裂位置的推测及地震断裂性质的判断。 相似文献
2.
MA Yinsheng LONG Changxing TAN Chengxuan WANG Tao GONG Mingquan LIAO Chunting WU Manlu SHI Wei DU Jianjun PAN Feng 《《地质学报》英文版》2009,83(4):713-723
Abstract: There are two co-seismic faults which developed when the Wenchuan earthquake happened. One occurred along the active fault zone in the central Longmen Mts. and the other in the front of Longmen Mts. The length of which is more than 270 km and about 80 km respectively. The co-seismic fault shows a reverse flexure belt with strike of N45°–60°E in the ground, which caused uplift at its northwest side and subsidence at the southeast. The fault face dips to the northwest with a dip angle ranging from 50° to 60°. The vertical offset of the co-seismic fault ranges 2.5–3.0 m along the Yingxiu-Beichuan co-seismic fault, and 1.5–1.1 m along the Doujiangyan-Hanwang fault. Movement of the co-seismic fault presents obvious segmented features along the active fault zone in central Longmen Mts. For instance, in the section from Yingxiu to Leigu town, thrust without evident slip occurred; while from Beichuan to Qingchuan, thrust and dextral strike-slip take place. Main movement along the front Longmen Mts. shows thrust without slip and segmented features. The area of earthquake intensity more than IX degree and the distribution of secondary geological hazards occurred along the hanging wall of co-seismic faults, and were consistent with the area of aftershock, and its width is less than 40km from co-seismic faults in the hanging wall. The secondary geological hazards, collapses, landslides, debris flows et al., concentrated in the hanging wall of co-seismic fault within 0–20 km from co-seismic fault. 相似文献
3.
活动断层是城市地震灾害的重要风险源，准确厘定活动断层的空间几何展布是有效降低城市地震灾害和开展活动断层避让的基础。而城市化建设对原始地貌的严重改造使得原先出露地表的活动断层成为"隐形"断层，难以准确确定断层的几何展布。大同盆地中部的水峪断裂北段位于马铺山东缘，断错地貌明显，但南段进入大同市御东新区被城市建筑物覆盖，成为"隐形"断层。研究基于大同地区1965年历史航片影像资料，结合1∶10000地形图，运用航片像对和航空立体摄影的方法重建了该地区的数字高程模型（DEM）和正射影像（DOM），重点对水峪断裂"隐形"段进行识别和定位，厘定了水峪断裂断层陡坎的几何展布特征。研究结果表明，水峪断裂北段山前陡坎线性特征明显，由影像可以准确解译出断层几何展布位置；水峪断裂南段可基于2000年之前的Keyhole历史遥感影像、DOM与DEM资料，根据断层两侧的颜色差异及陡坎高度差异，精确厘定该段的断层几何展布位置；DEM提取的地形剖面表明"隐形"段陡坎高度在19 m左右。同时，基于野外调查的断层剖面与浅层人工地震剖面证明该陡坎就是水峪断裂的位置，这也表明利用历史航卫片对城市"隐形"活动断层进行精确定位的方法是可行的。该研究不仅为大同地区的地震危险性评估提供了重要依据，而且为城市"隐形"活动断层探测提供了一个新的思路和途径。 相似文献
4.
中国活动构造研究的进展与展望 总被引：20，自引：0，他引：20
本文试图在世界活动构造研究背景下概括中国活动构造研究的进展，并对最近20年来中国的活动构造研究，包括几何学、滑动速率、古地震和大震重复间隔、分段理论和应用、活动褶皱、深浅构造耦合关系、城市和海域活动构造探测、块体划分和块体运动、地震危险性的未来断裂滑动量评价及中国现代构造活动动力学等进行简要评述，对今后在这些方面的发展进行概略的讨论。 相似文献
5.
Ezzadin N. Baban Bakhtiar Q. Aziz Nawzad H. Aziz 《Arabian Journal of Geosciences》2014,7(6):2279-2291
The study is carried out to detect the subsurface structures that have geological and economic importance by interpreting the available seismic reflection data of an area estimated to be about 1,752 km2. The study comprises of the Kalar–Khanaqin and surrounding area, which is located at Zagros folded zone. Twenty-five seismic sections had been interpreted. The total length of all the seismic lines is about 650.4 km. Interpretation of the seismic data is focused on two reflectors, lower Fars and Jeribe formation. The lower Fars reflector picked at the two-way time ranging from 0.1 to 2.6 second, while the Jeribe reflector picked at the two-way time ranging from 1.0 to 2.7 second. The constructed maps denote to the existence of many closed and nose structures, in addition, to numerous fault types. All these features were detected in the area having the NW–SE trend. The depth of the lower Fars formation is ranging from 100.0 to 4,800.0 m, while the depth of the Jeribe formation is ranging from 1,700.0 to 5,000.0 m. The depth maps for the two formations also refer to the similarity of the major geological structures. These structures appear in both formations with existence of slight variation in dimensions. The closed structure no. (1) is located at the north of the study area. The nose structure no. (2) is located at the south of the area. At the west of the area, the elongated structure no. (3). The longitudinal reveres fault intersects the SW limb of the structure. The SW limb of elongated structure no. (4), intersect by longitudinal reveres fault, is located at the east of the area. There is also the semi-closed structure no. (5), which appears at the west of the area around the Qr-1 well. Most of detected faults are of reverse and thrust types having a variable amount of throws and horizontal displacements. Some seismic sections explained the existence of the decollement surface within lower Fars formation, which caused the thrusting and faulting of the overlaying beds. 相似文献
6.
Danilo Cavallaro Carmelo Monaco Alina Polonia Attilio Sulli Agata Di Stefano 《Natural Hazards》2017,86(2):233-251
In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single- and multi-channel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a ~80-km-long deformation belt, characterized by a set of WNW–ESE to NW–SE fault segments showing a poly-phasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean–Piacenzian time by dextral strike-slip motion, as a consequence of the Africa–Europe convergence; ii) releasing and restraining bend geometries forming well-developed pull-apart basins and compressive structures. In the central and western sectors of the belt, we identified local transpressional reactivations of Piacenzian time, attested by well-defined compressive features like push-up structures and fault-bend anticlines. The reconstruction of timing and style of tectonic deformation suggest a strike-slip reactivation of inherited normal faults and the local subsequent positive tectonic inversion, often documented along oblique thrust ramps. This pattern represents a key for an improved knowledge of the structural style of foreland fold-and-thrust belts propagating in a preexisting extensional domain. With regard to active tectonics and seismic hazards, recent GPS data and local seismicity events suggest that this deformation process could be still active and accomplished through deep-buried structures; moreover, several normal faults showing moderate displacements have been identified on top of the Madrepore Bank and Malta High, offsetting the Late Quaternary deposits. Finally, inside the northern part of the Gela Basin, multiple slope failures, originated during Pleistocene by the further advancing of the Gela Nappe, reveal tectonically induced potential instability processes. 相似文献
7.
The paper considers the morphology, deep structure, and geodynamic features of the Ural–Herirud postorogenic strike-slip fault (UH fault), along which the Moho (the “M”) shifts along the entire axial zone of the Ural Orogen, then further to the south across the Scythian–Turan Plate to the Herirud sublatitudinal fault in Afghanistan. The postcollisional character of dextral displacements along the Ural–Herirud fault and its Triassic–Jurassic age are proven. We have estimated the scale of displacements and made an attempt to make a paleoreconstruction, illustrating the relationship between the Variscides of the Urals and the Tien Shan before tectonic displacements. The analysis of new data includes the latest generation of 1: 200000 geological maps and the regional seismic profiling data obtained in the most elevated part of the Urals (from the seismic profile of the Middle Urals in the north to the Uralseis seismic profile in the south), as well as within the sedimentary cover of the Turan Plate, from Mugodzhary to the southern boundaries of the former water area of the Aral Sea. General typomorphic signs of transcontinental strike-slip fault systems are considered and the structural model of the Ural–Herirud postcollisional strike-slip fault is presented. 相似文献
8.
第四纪断层上断裂活动的群集及迁移现象 总被引：16，自引：1，他引：16
对许多第四纪断层上形成地表破裂的巨大滑动事件及错动位移状况的具体研究表明,在不同时间段它们的数量和强度是变化的,不均匀的。这种断层活动的不均匀性主要表现在两个方面:一是滑动事件的发生往往集中于一定的地段和一定的时间段,并与相对平静的阶段相交替,即所谓断裂活动的群集性;另一方面的表现是集中发生滑动事件段落(或区域)在空间上的迁移变化。这是中国大陆内部第四纪断层活动所表现出的主要特征之一。这方面的实例可见于许多活断层上。如沿郯庐断层、鲜水河断层以及河西走廊断裂带、阿尔金断裂带等。深入研究第四纪断层活动的这一不均匀特性对正确评估活断层的活动程度和潜在地震危险性具有实际应用意义。 相似文献
9.
《Journal of Structural Geology》2001,23(2-3):473-487
Focal mechanism and surface slip data are used to investigate whether kinematics are similar at depth and at the surface along an active normal fault in the Gulf of Corinth, Greece. We present a new database of slip data from the lateral termination of the South Alkyonides fault segment (SAFS) and the en échelon stepover between it and an adjacent fault, and use published data on surface slip and focal mechanism data pertaining to slip at depth during the 1981 Alkyonides earthquake sequence. The focal mechanisms exhibit similar fault plane orientations and kinematics to those measured at the surface. Within the stepover, both data sets show that contemporaneous c. N–S and c. E–W extension is being accommodated by c. E–W- and c. N–S-oriented normal faults, and the overall deformation is distributed oblate vertical flattening. The deviation of the surface slip direction from 350° increases with distance from the centre of the SAFS. The deviation of the focal mechanism T-axes from 350° fit well with the surface data, implying that the coseismic slip on the SAFS at depths of 7–10 km exhibits a similar kinematic pattern as that observed at the surface. Our results imply that it is critical to know the along-strike position of data on a fault if either focal mechanisms or surface slip are to be used to infer regional strain and stress trajectories. 相似文献
10.
Xuanmei Fan Gianvito Scaringi Qiang Xu Weiwei Zhan Lanxin Dai Yusheng Li Xiangjun Pei Qin Yang Runqiu Huang 《Landslides》2018,15(5):967-983
On 8th August 2017, a magnitude Ms 7.0 earthquake struck the County of Jiuzhaigou, in Sichuan Province, China. It was the third Ms ≥?7.0 earthquake in the Longmenshan area in the last decade, after the 2008 Ms 8.0 Wenchuan earthquake and the 2013 Ms 7.0 Lushan earthquake. The event did not produce any evident surface rupture but triggered significant mass wasting. Based on a large set of pre- and post-earthquake high-resolution satellite images (SPOT-5, Gaofen-1 and Gaofen-2) as well as on 0.2-m-resolution UAV photographs, a polygon-based interpretation of the coseismic landslides was carried out. In total, 1883 landslides were identified, covering an area of 8.11 km2, with an estimated total volume in the order of 25–30?×?106 m3. The total landslide area was lower than that produced by other earthquakes of similar magnitude with strike-slip motion, possibly because of the limited surface rupture. The spatial distribution of the landslides was correlated statistically to a number of seismic, terrain and geological factors, to evaluate the landslide susceptibility at regional scale and to identify the most typical characteristics of the coseismic failures. The landslides, mainly small-scale rockfalls and rock/debris slides, occurred mostly along two NE-SW-oriented valleys near the epicentre. Comparatively, high landslide density was found at locations where the landform evolves from upper, broad valleys to lower, deep-cut gorges. The spatial distribution of the coseismic landslides did not seem correlated to the location of any known active faults. On the contrary, it revealed that a previously-unknown blind fault segment—which is possibly the north-western extension of the Huya fault—is the plausible seismogenic fault. This finding is consistent with what hypothesised on the basis of field observations and ground displacements. 相似文献
11.
The Bekten Fault is 20-km long N55°E trending and oblique-slip fault in the dextral strike-slip fault zone. The fault is extending sub-parallel between Yenice-Gönen and Sar?köy faults, which forms the southern branch of North Anatolian Fault Zone in Southern Marmara Region. Tectonomorphological structures indicative of the recent fault displacements such as elongated ridges and offset creeks observed along the fault. In this study, we investigated palaeoseismic activities of the Bekten Fault by trenching surveys, which were carried out over a topographic saddle. The trench exposed the fault and the trench stratigraphy revealed repeated earthquake surface rupture events which resulted in displacements of late Pleistocene and Holocene deposits. According to radiocarbon ages obtained from samples taken from the event horizons in the stratigraphy, it was determined that at least three earthquakes resulting in surface rupture generated from the Bekten Fault within last ~1300 years. Based on the palaeoseismological data, the Bekten Fault displays non-characteristic earthquake behaviour and has not produced any earthquake associated with surface rupture for about the last 400 years. Additionally, the data will provide information for the role of small fault segments play except for the major structures in strike-slip fault systems. 相似文献
12.
《International Geology Review》2012,54(9):991-1012
The active kinematics of the eastern Tibetan Plateau are characterized by the southeastward movement of a major tectonic unit, the Chuan-Dian crustal fragment, bounded by the left-lateral Xianshuihe–Xiaojiang fault in the northeast and the right-lateral Red River–Ailao Shan shear zone in the southwest. Our field structural and geomorphic observations define two sets of young, active strike–slip faults within the northern part of the fragment that lie within the SE Tibetan Plateau. One set trends NE–SW with right-lateral displacement and includes the Jiulong, Batang, and Derong faults. The second set trends NW–SE with left-lateral displacement and includes the Xianshuihe, Litang, Xiangcheng, Zhongdian, and Xuebo faults. Strike–slip displacements along these faults were established by the deflection and offset of streams and various lithologic units; these offsets yield an average magnitude of right- and left-lateral displacements of ～15–35 km. Using 5.7–3.5 Ma as the time of onset of the late-stage evolution of the Xianshuihe fault and the regional stream incision within this part of the plateau as a proxy for the initiation age of conjugate strike–slip faulting, we have determined an average slip rate of ～2.6–9.4 mm/year. These two sets of strike–slip faults intersect at an obtuse angle that ranges from 100° to 140° facing east and west; the fault sets define a conjugate strike–slip pattern that expresses internal E–W shortening in the northern part of the Chuan-Dian crustal fragment. These conjugate faults are interpreted to have experienced clockwise and counterclockwise rotations of up to 20°. The presence of this conjugate fault system demonstrates that this part of the Tibetan Plateau is undergoing not only southward movement, but also E–W shortening and N–S lengthening due to convergence between the Sichuan Basin and the eastern Himalayan syntaxis. 相似文献
13.
P. J. Lyon P. J. Boult R. R. Hillis K. Bierbrauer 《Australian Journal of Earth Sciences》2013,60(5):675-689
The Penola Trough is an intensely faulted northwest – southeast-trending half-graben structure. It is bound to the south by the major listric Hungerford/Kalangadoo Fault system. Several large prominent faults observed in the Penola Trough show offset of basement at depth. These basement-rooted faults have exerted significant controls on the geometry of smaller intra-rift faults throughout the entire structural history of the area. Faulting of the basement was initiated during the initial rift event of the Late Jurassic – Early Cretaceous. Faulting first propagated through a pre-existing basement fabric oblique to the north – south extension direction prevalent during this time. This resulted in the formation of the Hungerford/Kalangadoo and St George Faults with a northwest – southeast and north-northeast – south-southwest trend, respectively. A series of east – west-trending basement faults subsequently initiated perpendicular to the north – south extension direction as extensional strain increased in magnitude. Significant displacement along these basement-rooted faults throughout the initial rift event was associated with the formation of a complex set of intra-rift faults. These intra-rift faults exhibit a broadly east – west orientation consistent with the interpreted north – south extensional direction. However, this east – west orientation locally deviates to a more northwest – southeast direction near the oblique-trending St George Fault, attributed to stress perturbation effects. Many of the intra-rift faults die out prior to the end of the Early Cretaceous initial rift event while displacement on basement faults continued throughout. Faulting activity during the Late Cretaceous post-rift fault event was almost exclusively localised onto basement faults, despite a significant change in extension direction to northeast – southwest. A high-density, en échelon array of northwest – southeast-trending fault segments formed directly above the St George Fault and the large east – west-trending basement faults contemporaneously reactivated. Seismic variance data show that post-rift fault segments that are hard-linked to the St George Fault at depth have propagated through near-surface units. Non-basement-linked post-rift fault segments that lie away from the St George basement have not. This suggests that recent fault activity has continued to occur preferentially along basement faults up to relatively recent times, which has significant implications for fault seal integrity in the area. This is empirically validated by our structural analysis of fault-dependent hydrocarbon traps in the area, which shows that partially breached or breached hydrocarbon columns are associated with basement faults, whereas unbreached hydrocarbon columns are not. 相似文献
14.
Bora Uzel 《Geodinamica Acta》2016,28(4):311-327
Linking of normal faults forms at all scales as a relay ramp during growth stages and represents the most efficient way for faults to lengthen during their progressive formation. Here, I study the linking of normal faulting along the active K?rka?aç Fault Zone within the west Anatolian extensional system to reconstruct fault interaction in time and space using both field- and computer-based data. I find that (i) connecting of the relay zone/ramp occurred with two breaching faults of different generations and that (ii) the propagation was facilitated by the presence of pre-existing structures, inherited from the ?zmir-Bal?kesir transfer zone. Hence, the linkage cannot be compared directly to a simple fault growth model. Therefore, I propose a combined scenario of both hangingwall and footwall fault propagation mechanisms that explain the present-day geometry of the composite fault line. The computer-based analyses show that the approximate slip rate is 0.38 mm/year during the Quaternary, and a NE–SW-directed extension is mainly responsible for the recent faulting along the K?rka?aç Fault Zone. The proposed structural scenario also highlights the active fault termination and should be considered in future seismic hazard assessments for the region that includes densely populated settlements. 相似文献
15.
Cavallaro Danilo Monaco Carmelo Polonia Alina Sulli Attilio Di Stefano Agata 《Natural Hazards》2016,86(2):233-251
In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single- and multi-channel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a ~80-km-long deformation belt, characterized by a set of WNW–ESE to NW–SE fault segments showing a poly-phasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean–Piacenzian time by dextral strike-slip motion, as a consequence of the Africa–Europe convergence; ii) releasing and restraining bend geometries forming well-developed pull-apart basins and compressive structures. In the central and western sectors of the belt, we identified local transpressional reactivations of Piacenzian time, attested by well-defined compressive features like push-up structures and fault-bend anticlines. The reconstruction of timing and style of tectonic deformation suggest a strike-slip reactivation of inherited normal faults and the local subsequent positive tectonic inversion, often documented along oblique thrust ramps. This pattern represents a key for an improved knowledge of the structural style of foreland fold-and-thrust belts propagating in a preexisting extensional domain. With regard to active tectonics and seismic hazards, recent GPS data and local seismicity events suggest that this deformation process could be still active and accomplished through deep-buried structures; moreover, several normal faults showing moderate displacements have been identified on top of the Madrepore Bank and Malta High, offsetting the Late Quaternary deposits. Finally, inside the northern part of the Gela Basin, multiple slope failures, originated during Pleistocene by the further advancing of the Gela Nappe, reveal tectonically induced potential instability processes.
相似文献16.
The seismic hazard for the Lake Van basin is computed using a probabilistic approach, along with the earthquake data from 1907 to present. The spatial distribution of seismic events between the longitudes of 41–45° and the latitudes of 37.5–40°, which encompasses the region, indicates distinct seismic zones. The positions of these zones are well aligned with the known tectonic features such as the Tutak-Çald?ran fault zone, the Özalp fault zone, the Geva? fault zone, the Bitlis fault zone and Karl?ova junction where the North Anatolian fault zone and East Anatolian fault zone meet. These faults are known to have generated major earthquakes which strongly affected cities and towns such as Van, Mu?, Bitlis, Özalp, Muradiye, Çald?ran, Erci?, Adilcevaz, Ahlat, Tatvan, Geva? and Gürp?nar. The recurrence intervals of M s ≥ 4 earthquakes were evaluated in order to obtain the parameters of the Gutenberg–Richter measurements for seismic zones. More importantly, iso-acceleration maps of the basin were produced with a grid interval of 0.05 degrees. These maps are developed for 100- and 475- year return periods, utilizing the domestic attenuation relationships. A computer program called Sistehan II was utilized to generate these maps. 相似文献
17.
Constraining slip rates and spacings for active normal faults 总被引：1，自引：0，他引：1
Numerous observations of extensional provinces indicate that neighbouring faults commonly slip at different rates and, moreover, may be active over different time intervals. These published observations include variations in slip rate measured along-strike of a fault array or fault zone, as well as significant across-strike differences in the timing and rates of movement on faults that have a similar orientation with respect to the regional stress field. Here we review published examples from the western USA, the North Sea, and central Greece, and present new data from the Italian Apennines that support the idea that such variations are systematic and thus to some extent predictable. The basis for the prediction is that: (1) the way in which a fault grows is fundamentally controlled by the ratio of maximum displacement to length, and (2) the regional strain rate must remain approximately constant through time. We show how data on fault lengths and displacements can be used to model the observed patterns of long-term slip rate where measured values are sparse. Specifically, we estimate the magnitude of spatial variation in slip rate along-strike and relate it to the across-strike spacing between active faults. 相似文献
18.
Review of paleoseismological and active fault studies in Taiwan in the light of the Chichi earthquake of September 21, 1999 总被引：1，自引：0，他引：1
This paper reviews the research on active and earthquake faults in Taiwan conducted prior and after the 1999 Chichi earthquake. The Chichi earthquake plays as a turning point of the relevant studies, since the 1999 coseismic surface rupture exactly follows preexisting fault scarps, created in turn by previous seismic events along the Chelungpu Fault. This fact indicates that the precise mapping on the other active faults is fundamental to predict the location of surface rupture caused by large future earthquakes. Since 1999, many trenching studies have been carried out along the Chichi earthquake fault. A few of them demonstrates that the penultimate event is as young as probably only 200–430 years old; however, some others show a rather old age of several hundreds years or even older for the last faulting event before 1999. More trenching studies are necessary for such a long fault in order to understand the possible segmentation features and the correlation of the paleoseismic events identified along the entire fault length. In addition, we further discuss the offshore faulting associated with seismic event along the eastern coast of Taiwan, where the multiple Holocene terraces are well known. 相似文献
19.
Santi Pailoplee 《Natural Hazards》2014,74(3):1813-1827
In this study, the earthquake hazard was evaluated for all of 19 of the proposed or built dams along the Mekong River. All values representing a potential indication of hazardous earthquakes, such as the closest earthquake and seismogenic faults and including the seismic parameters required for a seismic safety evaluation, were clarified. The results will be useful in reviewing the safety of existing dams and for the design of suitable earthquake resistant specifications for any currently or future planned dam construction in this area. Seismotectonically, 14 of the 19 proposed Mekong River dams are located within an earthquake source zone. Most of faults are potentially still active, according to both seismicity and paleoseismological evidence. In addition, the maximum credible earthquakes were estimated to be in the range of 7–8 Mw for the closest fault zone of each dam. Previous isoseismal maps indicated a risk of shaking intensities of around scale III–IV (Modified Mercalli Intensity Scale) for the dams. According to the preliminary ranging of the International Commission on Large Dams, 9 of these 19 dams are classified as in an extreme hazard class and so need careful observation and monitoring of hazardous earthquakes. An effective mitigation plan should also be prepared for each operating dam. 相似文献
20.
汶川8级地震地质灾害的类型及实例 总被引：11，自引：2，他引：9
龙门山地区活动断裂右旋斜冲运动与汶川8级强烈地震存在成因联系。汶川8级地震造成了惨重的人员伤亡和巨大的财产损失,地震地质灾害主要类型有地震灾害、地震触发地质灾害和地震引发地质灾害隐患。严重地震灾害包括房屋倒塌与部分坍塌、房屋平移、房屋倾斜变形、墙体破裂与结构破坏、桥梁垮塌等。地震触发严重地质灾害包括山体滑坡、山体滑塌、岩块崩塌,局部产生泥石流与沙土液化。地震引发地质灾害隐患包括潜在滑坡、不稳定边坡与滑塌隐患、危岩体与崩塌隐患及泥石流灾害隐患。地震地质灾害分布与活动断层存在密切关系,沿北川映秀断裂地震地质灾害最为严重,沿汉旺漩口断裂、茂县汶川断裂、青川断裂地震地质灾害也比较严重。在活动断裂之间相对稳定地块远离活动断裂超过3~5 km,地震灾害和地震触发地质灾害显著减轻。 相似文献