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Introduction With rapid development of national economy, urbanization has been speeded up in China, and several city groups or city belts with extra-large cities as their centers have been formed. For example, Pearl River Delta urbanized area surrounds Guangzhou City, Shenzhen City, Zhuhai City; Yangtze River Delta urbanized area surrounds Shanghai City, Suzhou City, Wuxi City, Nanjing City, Hangzhou City; Beijing-Tianjin-Tangshan urbanized area surrounds Beijing City, Tianjin City… 相似文献
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通过搜集江西省各地方史志地震记载,在前人研究基础上,给出江西省历史有感地震的筛选原则和确定方法,整理分析相应有感地震,并在中国有感地震目录中提取江西有感地震,删减重复部分,增补遗漏的史志有记载的有感地震,从而编辑江西地区相对完整的历史有感地震目录。 相似文献
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ＡｕｎｉｆｏｒｍｃａｔａｌｏｇｏｆｅａｒｔｈｑｕａｋｅｓｆｏｒｓｅｉｓｍｉｃｈａｚａｒｄａｓｅｓｍｅｎｔｉｎＩｒａｎＮｏｏｒｂａｋｈｓｈＭｉｒｚａｅｉ１，２）ＭＥＮＧ－ＴＡＮＧＡＯ１）（高孟谭）ＹＵＮ－ＴＡＩＣＨＥＮ１）（陈运泰）ＪＩＡＮＷＡＮＧ１... 相似文献
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Firstly, the impact of historical earthquakes on 34 China province-level capital cities is evaluated by using historical earthquake
catalog. The distribution of affected intensity shows, about 53% of cities have even not been affected by earthquake intensity
VI, and 44% of cities have been hit by earthquake intensity VII to IX. For most of the cities, occurrence frequency of affected
intensity VI is usually higher than that of affected intensity larger than VI, and the value of affected intensity with maximal
occurrence frequency may be very different among cities. So both the maximal affected intensity and the affected intensity
with maximal occurrence frequency should be taken into account when the prevention seismic intensity needs to be determined.
Secondly, considering the incompleteness of records of historical earthquakes, a method of earthquake catalog computer simulation
is introduced to study the features of affected intensity of big cities. 69 county-level cities of Fujian Province are selected
to be statistical objects. The statistical result shows, for different risk levels the seismic intensity changes greatly among
cities, the seismic intensity of 2% probability of exceedance in 50 years can be regarded as the characteristic affected intensity
of city, and can be the basis of determining the city special earthquake prevention level and a proper indicator of future
earthquake’s impact on cities.
Foundation item: A Public Benefit Foundation of the Ministry of Science and Technology of China. Contribution No. 04FE1005,
Institute of Geophysics, China Earthquake Administration. 相似文献
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The analysis of seismic hazards relies on the statistical analysis of historical seismic data and the instrumental seismic catalog to obtain the regional earthquake recurrence interval and earthquake probability. The accuracy of analysis thus depends strongly on the completeness of the seismic data used. However, available seismic catalogs are too short or incomplete for the reliable analysis of the statistical characteristics of earthquakes. If a long-term synthetic seismic catalog can be generated using a physics-based numerical simulation, and the simulation results match the crustal deformation, seismicity, and other observations,then such a synthetic catalog helps us to further understand the characteristics of seismic activity and analyze the regional seismic hazard. In this paper, taking the northeastern Tibetan Plateau as a case study, we establish a three-dimensional visco-elastoplastic finite-element model to simulate earthquake cycles and the spatiotemporal evolution of earthquakes on the model fault system and obtain a seismic catalog on a time scale of tens of thousands of years. On the basis that the model satisfies the regional geodynamics of the northeastern Tibetan Plateau, we analyze seismicity on the northeastern Tibetan Plateau using the simulated synthetic earthquake catalog. The characteristics of earthquake recurrence at different locations and different magnitudes, and the long-term average probability of earthquake occurrence within the fault system on the northeastern Tibetan plateau are studied. The results are a reference for regional seismic hazard assessment and provide a basis for the physics-based numerical prediction of earthquakes. 相似文献
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使用单键群方法研究了2011年3月11日日本本州东北部海域9.0级地震前地震空间相关长度变化。结果表明,在本次地震发生前约两年,5级以上地震的空间相关长度开始出现明显增长,变化趋势可以用幂次率进行很好的拟合。用没有7级以上强震发生的时段内的地震目录,采用相同方法进行了计算,没有发现明显的幂次率增长现象,说明强震前5级以上地震的空间相关长度的幂次率增长是地震孕育过程中震源区的物理性质特征的表现之一。 相似文献
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青藏高原东北隅地区位于青藏高原、鄂尔多斯和阿拉善三大块体交汇部位,发育一组以逆走滑活动为主的弧形断裂系,其新活动性强,历史及现代强震频发,是探讨现代中小地震密集区与历史强震关联性的理想地区,也是检验和发展小震密集区值方法及其适用条件的有利地区。本文采用甘肃省地震局对该区1970年以来1～5级地震仪器监测目录,利用网格点密集值方法进行计算分析,共划分出21个地震密集区。通过分析每个地震密集区内小震活动的时间分布特征及前人对历史地震和活动构造的研究结果,综合判断地震密集区与历史强震之间的对应关系,归纳总结不同震级历史强震密集区的持续时间,给出运用网格点密集值方法校核青藏高原东北隅历史地震的限定条件。研究结果表明:青藏高原东北隅弧形构造区大约66.7%的密集区对应历史强震,两者之间有较密切的关联性;且地震震级越大密集区持续时间越长,两者之间的拟合关系为:T=4.38×10~(-7)×M~(10.91)。 相似文献
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L. L. Romachkova V. G. Kossobokov G. F. Panza G. Costa 《Pure and Applied Geophysics》1998,152(1):37-55
—Large earthquakes in Italy are preceded by a specific seismic activation which could be diagnosed by a reproducible intermediate-term earthquake prediction method—a modification for lower seismic rate areas of the algorithm, known as M8 (Keilis-Borok and Kossobokov, 1990). Use has been made of the PFG-ING catalog of earthquakes, compiled on a regular basis, to determine areas and times of increased probability for occurrences of M≥ 6 earthquakes. In retroactive simulation of forward prediction, for the period 1972–1995, both the 1976 Friuli, M = 6.1 and the 1980 Irpinia, M = 6.5 earthquakes are predicted. In the experiment where priority magnitude scale is used, the times of increased probability for a strong earthquake to occur (TIPs) occupy less than a quarter of the total magnitude-space-time domain, and are rather stable with respect to positioning of circles of investiga tion. Successful stability tests have been made considering a recently compiled catalog (CCI97) (Peresan et al., 1997). In combination with the CN algorithm results (Costa et al., 1996) the spatio-temporal uncertainty of the prediction could be reduced to 5%. The use of M8 for the forward prediction requires the computations to be repeated each half-year, using the updated catalog. 相似文献
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Trevor I. Allen David J. Wald Paul S. Earle Kristin D. Marano Alicia J. Hotovec Kuowan Lin Michael G. Hearne 《Bulletin of Earthquake Engineering》2009,7(3):701-718
We present an Atlas of ShakeMaps and a catalog of human population exposures to moderate-to-strong ground shaking (EXPO-CAT)
for recent historical earthquakes (1973–2007). The common purpose of the Atlas and exposure catalog is to calibrate earthquake
loss models to be used in the US Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER). The full
ShakeMap Atlas currently comprises over 5,600 earthquakes from January 1973 through December 2007, with almost 500 of these
maps constrained—to varying degrees—by instrumental ground motions, macroseismic intensity data, community internet intensity
observations, and published earthquake rupture models. The catalog of human exposures is derived using current PAGER methodologies.
Exposure to discrete levels of shaking intensity is obtained by correlating Atlas ShakeMaps with a global population database.
Combining this population exposure dataset with historical earthquake loss data, such as PAGER-CAT, provides a useful resource
for calibrating loss methodologies against a systematically-derived set of ShakeMap hazard outputs. We illustrate two example
uses for EXPO-CAT; (1) simple objective ranking of country vulnerability to earthquakes, and; (2) the influence of time-of-day
on earthquake mortality. In general, we observe that countries in similar geographic regions with similar construction practices
tend to cluster spatially in terms of relative vulnerability. We also find little quantitative evidence to suggest that time-of-day
is a significant factor in earthquake mortality. Moreover, earthquake mortality appears to be more systematically linked to
the population exposed to severe ground shaking (Modified Mercalli Intensity VIII+). Finally, equipped with the full Atlas
of ShakeMaps, we merge each of these maps and find the maximum estimated peak ground acceleration at any grid point in the
world for the past 35 years. We subsequently compare this “composite ShakeMap” with existing global hazard models, calculating
the spatial area of the existing hazard maps exceeded by the combined ShakeMap ground motions. In general, these analyses
suggest that existing global, and regional, hazard maps tend to overestimate hazard. Both the Atlas of ShakeMaps and EXPO-CAT
have many potential uses for examining earthquake risk and epidemiology. All of the datasets discussed herein are available
for download on the PAGER Web page ().
T. I. Allen and M. G. Hearne—contracted through Synergetics Incorporated. 相似文献
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Ya. B. Radziminovich 《Journal of Volcanology and Seismology》2013,8(5):314-321
The area of western Transbaikalia is characterized by moderate seismic activity. Nevertheless, there is historical and instrumental evidence to show that rather strong seismic events have occurred in the area and caused considerable material damage to the population centers around their epicenters. Seismological knowledge of the region is scant. The earthquake catalogs for the area and for the historical period of time need to be corrected and supplemented. The present paper considers the earthquake of October 9, 1864, which has not been included in any parametric catalog thus far. New primary data that were found in the regional periodic press were used to determine the epicenter and magnitude (M = 5.1) for the event. The earthquake of October 9, 1864 is a “forgotten” event, but is a significant addition to the catalog for western Transbaikalia. The materials presented here can be used to assess earthquake hazard for the area, as well as to aid in the search for other unknown or “forgotten” earthquakes. 相似文献
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地震目录资料是进行地震预测、地震危险性分析、地震活动性研究等地震学研究的基础资料.对地震目录资料的完整性可靠性分析是地震学研究的基础工作之一.近几十年来我国积累的大量的仪器地震记录,历史地震也在不断更新,为地震活动性研究提供了更为丰富的样本,因此有必要对新的地震目录进行完整性分析.本文采用了新的统计方法对我国仪器记录地震目录和历史破坏性地震目录进行了完整性分析.结果表明,对于仪器记录地震目录（M≥3.0）我国东部地区1975年后基本完整,西部地区1980年后基本完整.对于历史地震目录（M≥5.0）,东部地区1500年后基本完整,西部地区1950年后基本完整.考虑到华北地震区历史破坏性地震（M≥43/4）活动的时间非平稳性,我们采用突变点分析法研究了华北地震区历史破坏性地震目录的时间特征,得到了华北地震区地震活动周期性变化的突变点位置,并揭示了华北地震区历史破坏性地震目录完整起始时间约为公元1500年前后. 相似文献
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根据史料记载,各种地震目录均将东汉灵帝光和三年秋(公元180年)表氏地震震中定在甘肃省高台县西(39.4°N,99.5°E),震中烈度Ⅹ度,震级7(1/2).本文通过对历史地震资料的重新考证和表氏新旧县城遗址的实地考察,对公元180年表氏地震的震中位置作了如下修正:震前的表氏县城位于甘肃省肃南县明花区新墩子城,也应是震中所在地,其地理位置为39.6°N、99.3°E,精度2类;震后重建的县城在今骆驼城或草沟井城.通过对史料震害的认真分析,并将本次地震与两汉时期8次6(1/2)级以上地震及高台附近地区9次地震的地震参数、震害和波及范围进行对照,最终将震中烈度修正为Ⅸ—Ⅹ度,震级修正为7级. 相似文献
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在南北地震带地区,USGS全球地震目录中存在一些震源深度大于30km的地震.这些地震的震源深度是否可靠,对于研究这一地区的孕震机制、岩石圈强度和构造演化等科学问题具有重要意义.本文以南北地震带2012年发生的5个4~5级地震为例,利用区域地震台网的波形数据,基于sPL深度震相、短周期瑞利面波以及CAP等独立方法测定了其震源深度.结果表明:sPL深度震相和CAP方法给出的震源深度比较一致,差别小于2~3km,能够得到比较可靠的震源深度;短周期瑞利面波及其与P波振幅比也确定了地震震源深度较浅的特征.本文研究结果显示:宁夏会宁4.7级、云南富民4.8级和四川会东4.7级地震的震源深度约为8~12km左右,仍为发生于上地壳的地震,USGS地震目录给出的30km甚至更深的震源深度存在明显偏差;对于四川隆昌4.6和4.9级地震,本文给出的震源深度为1~2km,属于极浅源地震,USGS地震目录给出的10km和35km的震源深度结果尚需进一步改进. 相似文献
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川滇菱形块体及其边界断裂带(21°～33°N,96°～108°E)是中国大陆地震活动最强烈的地区之一,该地区发生的一系列大地震造成了巨大的人员伤亡和财产损失。文中分别应用基于地震空间相关性和地壳形变场的预测方法分析了该地区未来的地震危险性。由Kagan等(1994)提出的基于地震空间相关性的方法,假定未来发生地震的概率与历史发生地震的频度成正比,根据历史地震目录建立统计学模型估计未来发生地震的概率。回溯性检验表明,这种方法对于评估地震复发周期较短的断裂带的地震危险性有较高的有效性,但对于地震复发周期较长的断裂带,如龙门山断裂带,很难给出一个理想的预期。由Shen等(2007)提出的基于地壳形变场的方法,假定长期地震危险性与地壳构造应变率成正比,根据由GPS观测获得的应变率场建立统计学模型评估未来的地震危险性。回溯性检验表明,川滇地区过去30a间发生的地震与区域应变率的大小没有明显的对应关系,但过去500a间发生的地震与应变率场有很高的相关性,表明由10a时间尺度的大地测量资料得到的地壳应变场可以很好地反映数百a时间尺度的地震危险性。 相似文献
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新疆地震活动分布区域广,主要分布在南北天山、西昆仑、阿尔泰、阿尔金山与塔里木盆地和准噶尔盆地的衔接地带。各地震带地震活动水平不尽相同,其中南天山与北天山地震带以及帕米尔一西昆仑地震带的地震活动水平较高,地震活动呈西强东弱的特点。自2011年以来新疆境内地震活动呈现出5级地震连发,6级地震活动频繁,且各地震带均有分布的特点。利用新疆历史地震目录,分析新疆境内各片区发生地震活动是否具有相关性,并从中获得各片区地震活动相关性的量度,以此可以将这些量度作为新疆境内各片区地震中长期预报的辅助性分析方法。 相似文献
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2014年 8月3日在云南省鲁甸县发生MS6.5地震,造成了巨大的人员伤亡和财产损失.关于鲁甸地震的起因,特别是鲁甸地震与溪洛渡水库之间的关系存在一些争议.分析中强地震前后地震活动性的变化可以为判断主震起源提供一定的依据.然而,由于鲁甸地震震中附近固定台站数目少、台站距离震中远及主震后尾波干扰等因素的影响,会造成地震目录的缺失,从而可能影响地震活动性的可靠分析.为了获得更加完备的地震目录,本文采用模板匹配方法对鲁甸地震前后小地震进行了搜索和识别.以台网目录中的541个事件作为模板,在主震之前33天到主震后5天的连续波形中识别出991个未在目录中列出的地震,使余震的完备震级从1.8降低到1.3.根据检测目录得到主震前33天内的b值为1.04±0.18,余震的b值在震后5天内由0.5左右逐渐上升至0.9附近并保持稳定;根据2009年到主震发生前的台网目录得到该区域的背景b值为0.93±0.04.即鲁甸地震前后区域地震活动b值均与背景b值接近,这与典型水库诱发的中强震具有的b值特征不相符.同时通过进一步分析台网目录,未发现溪洛渡水库蓄水前后研究区域内的地震活动性存在明显变化,这也与典型水库诱发地震区域的地震活动性特征不相符.综合以上结果,我们认为2014年鲁甸MS6.5地震不具有典型水库诱发地震的特征. 相似文献
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在吸收历史地震研究、历史政区地理研究等多方面成果基础上,基于历史有感地震记载特点,探索了历史有感地震目录的编制原则,给出了地震日期、震中位置、震级的确定方法。以《中国地震历史资料汇编》等为依据,编制了公元前618年-公元1949年期间中国境内3≤M<443/4级历史有感地震目录9 121条。目录数量为中国同期文字记载的43/4级以上破坏性地震的7倍多,比全球其他国家或地区最早的同类目录早1 695年,约占全球同期M≤4.5级有感地震目录的2/3。 相似文献