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1.
This paper presents spatial variation of seismic hazard at the surface level for India,covering 6-38°N and 68-98°E.The most recent knowledge on seismic activity in the region has been used to evaluate the hazard incorporating uncertainties associated with the seismicity parameters using different modeling methodologies.Three types of seismic source models,viz.linear sources,gridded seismicity model and areal sources,were considered to model the seismic sources and different sets of ground motion prediction equations were used for different tectonic provinces to characterize the attenuation properties.The hazard estimation at bedrock level has been carried out using probabilistic approach and the results obtained from various methodologies were combined in a logic tree framework.The seismic site characterization of India was done using topographic slope map derived from Digital Elevation Model data.This paper presents estimation of the hazard at surface level,using appropriate site amplification factors corresponding to various site classes based on V_(S30) values derived from the topographic gradient.Spatial variation of surface level peak horizontal acceleration(PHA) for return periods of 475 years and 2475 years are presented as contour maps.  相似文献   

2.
The hazard assessment of potential earthquake-induced landslides is an important aspect of the study of earthquake-induced landslides. In this study, we assessed the hazard of potential earthquake-induced landslides in Huaxian County with a new hazard assessment method. This method is based on probabilistic seismic hazard analysis and the Newmark cumulative displacement assessment model. The model considers a comprehensive suite of information, including the seismic activities and engineering geological conditions in the study area, and simulates the uncertainty of the intensity parameters of the engineering geological rock groups using the Monte Carlo method. Unlike previous assessment studies on ground motions with a given exceedance probability level, the hazard of earthquake-induced landslides obtained by the method presented in this study allows for the possibility of earthquake-induced landslides in different parts of the study area in the future. The assessment of the hazard of earthquake-induced landslides in this study showed good agreement with the historical distribution of earthquake-induced landslides. This indicates that the assessment properly reflects the macroscopic rules for the development of earthquake-induced landslides in the study area, and can provide a reference framework for the management of the risk of earthquake-induced landslides and land planning.  相似文献   

3.
Fethiye is an important region located in the eastern part of the Mediterranean Basin.This region which is the most active part of the south-western Anatolia extensional tectonic regime,has been effected by earthquakes,submarine landslides and tsunamis throughout the history due to the existence of the complex active plate boundary zone.The active area has been exposed to ground motion that had the potential to damage vulnerable structures.Therefore,a detailed assessment of seismic hazard is necessary for the prevention of potential damage.In this context,probabilistic seismic hazard analysis is performed by R-CRISIS-18.3 using the refined parameters computed from Seismic Hazard Harmonization for Europe(SHARE)project.Spatial distribution of spectral acceleration at T=0.2 s and T=1.0 s for the earthquake levels that corresponds to the average return period of 72,475 and 2475 years is calculated.Hazard curves for the central region of Fethiye district are generated.The results are discussed and compared with the values obtained from the Revision of Turkish Seismic Hazard Map Project(UDAP-C-13-06).These local results of probabilistic seismic hazard analysis will provide the basis for the preparation of seismic risk maps as future work.  相似文献   

4.
On April 20 th, 2013, an earthquake of magnitude MW 6.6 occurred at Lushan of Sichuan on the southern segment of the Longmenshan fault zone, with no typical coseismic surface rupture. This work plotted an isoseismal map of the earthquake after repositioning over 400 post–earthquake macro–damage survey points from peak ground acceleration(PGA) data recorded by the Sichuan Digital Strong Earthquake Network. This map indicates that the Lushan earthquake has a damage intensity of IX on the Liedu scale, and that the meizoseismal area displays an oblate ellipsoid shape, with its longitudinal axis in the NE direction. No obvious directivity was detected. Furthermore, the repositioning results of 3323 early aftershocks, seismic reflection profiles and focal mechanism solutions suggests that the major seismogenic structure of the earthquake was the Dayi Fault, which partly defines the eastern Mengshan Mountain. This earthquake resulted from the thrusting of the Dayi Fault, and caused shortening of the southern segment of the Longmenshan in the NW–SE direction. Coseismal rupture was also produced in the deep of the Xinkaidian Fault. Based on the above seismogenic model and the presentation of coseismic surface deformation, it is speculated that there is a risk of more major earthquakes occurring in this region.  相似文献   

5.
This paper presents probabilistic assessment of seismically-induced slope displacements considering uncertainties of seismic ground motions and soil properties.A stochastic ground motion model representing both the temporal and spectral non-stationarity of earthquake shakings and a three-dimensional rotational failure mechanism are integrated to assess Newmark-type slope displacements.A new probabilistic approach that incorporates machine learning in metamodeling technique is proposed,by combining relevance vector machine with polynomial chaos expansions(RVM-PCE).Compared with other PCE methods,the proposed RVM-PCE is shown to be more effective in estimating failure probabilities.The sensitivity and relative influence of each random input parameter to the slope displacements are discussed.Finally,the fragility curves for slope displacements are established for sitespecific soil conditions and earthquake hazard levels.The results indicate that the slope displacement is more sensitive to the intensities and strong shaking durations of seismic ground motions than the frequency contents,and a critical Arias intensity that leads to the maximum annual failure probabilities can be identified by the proposed approach.  相似文献   

6.
Catastrophic natural hazards,such as earthquake,pose serious threats to properties and human lives in urban areas.Therefore,earthquake risk assessment(ERA)is indispensable in disaster management.ERA is an integration of the extent of probability and vulnerability of assets.This study develops an integrated model by using the artificial neural network–analytic hierarchy process(ANN–AHP)model for constructing the ERA map.The aim of the study is to quantify urban population risk that may be caused by impending earthquakes.The model is applied to the city of Banda Aceh in Indonesia,a seismically active zone of Aceh province frequently affected by devastating earthquakes.ANN is used for probability mapping,whereas AHP is used to assess urban vulnerability after the hazard map is created with the aid of earthquake intensity variation thematic layering.The risk map is subsequently created by combining the probability,hazard,and vulnerability maps.Then,the risk levels of various zones are obtained.The validation process reveals that the proposed model can map the earthquake probability based on historical events with an accuracy of 84%.Furthermore,results show that the central and southeastern regions of the city have moderate to very high risk classifications,whereas the other parts of the city fall under low to very low earthquake risk classifications.The findings of this research are useful for government agencies and decision makers,particularly in estimating risk dimensions in urban areas and for the future studies to project the preparedness strategies for Banda Aceh.  相似文献   

7.
Geothermal resources exist in complex and comprehensive geological settings. In the current study, we proposed a CPU/GPU collaborative parallel prestack time migration methodology for geothermal resource exploration. First, seismic geological conditions in Xian County were obtained based on an analysis of drill cores for further seismic evaluation. Then, combined with the analysis of two-dimensional seismic data in the adjacent area, a test section with three seismic survey lines were designed to explore the geological structure of the study area. In the study area, the seismic data were derived through the multiple coverage reflection wave exploration method with explosive ignition in deep wells and high coverage frequency observations. Finally, we employed CPU/GPU collaborative parallel prestack time migration technology to analyze the obtained seismic data for geothermal resource evaluation. The favorable areas of karst fissure heat storage in Middle–Upper Proterozoic Jixianian and Paleozoic Cambrian–Ordovician rocks were inferred together with two preferred recommended exploration holes.  相似文献   

8.
Western Yunnan is located within a gigantic Tethys orogenic zone between Gondwana and Laurasia. Magmatic activity records of the associated Wilson orogenic cycle show that the causes of plate spreading in the region might have been related to sub-mantle plume. Tectonics, geophysics, sedimentary strata, tectonic evolution of the lithosphere and other research results indicate that there is geological evidence for mantle plume magmatic activities in West Yunnan. Tomography also supports the idea that there is a subducting slab near the Red River fault and an upwelling mantle plume in West Yunnan. Here our research presents seismic evidence for upwelling mantle plume, which is a main cause leading to subducting slab in West Yunnan. The analysis is based on compressional-to-shear (P-to-S) converted seismic phases, recorded on seismograph stations in the Sichuan-Yunnan seismic network, and made a study on 410-km and 660-km discontinuities, as well as on three sections of CCP stacking.  相似文献   

9.
There is a NE-trending earthquake hazard anomalous zone in the western part of the area of the city ofBeijing proper. A comprehensive study of it has been made. In the study the two-dimensional finite element dy-namic analysis and supersonic seismic model experiments were conducted for the first time. and some prelimi-nary results have been achieved. The Beijing depression, a lower order tectonic unit in the Beijing downwarp, is just located below theearthquake hazard anomalous zone. Analysis of the experimental results shows that the topography of the bu-ried bedrock is the main factor responsible for the presence of the anomalous zone. Besides. thetwo-dimensional mathematical analysis has more marked advantages in reflecting the lateral inhomogeneity ofthe foundation as compared with the one-dimensional one. and the supersonic seismic model experiments mayreflect the integrated effects of the earthquake sources, path of wave propagation and site geological structurein an all-round way.  相似文献   

10.
The Maoshan area is an area with well-developed igneous rocks and complex structures. The thickness of the reservoirs is generally small. The study of the reservoirs is based on seismic data, logging data and geological data. Using techniques and software such as Voxelgeo, BCI, RM, DFM and AP, the authors have made a comprehensive analysis of the lateral variation of reservoir parameters in the Upper Shazu bed of the third member of the Palaeogene Funing Formation, and compiled the thickness map of the Shazu bed. Also, with the data from ANN, BCI and the abstracting method for seismic characteristic parameters in combination with the structural factors, the authors have tried the multi-parameter and multi-method prediction of petroleum, delineated the potential oil and gas areas and proposed two well sites. The prediction of oil and gas for Well JB2 turns out to be quite successful.  相似文献   

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