首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 83 毫秒
1.
2.
1995年1月24日江西省寻乌县发生ML4.5级地震,本文从震例的角度,对该次地震的地震地质背景,烈度分布与震害,地震序列,震源机制解和地震主破裂面,地震活动背景情况作了初步探讨,并对震源重新定位。  相似文献   

3.
1987年8月2日寻乌地震的破裂方式   总被引:2,自引:2,他引:2       下载免费PDF全文
雷士成  王耀东 《地震地质》1991,13(4):353-360
1987年8月2日,江西省寻乌发生M_S5.5级地震,震中烈度Ⅷ度,震中位于24°58′N,115°39′E,震源深度13km。本文根据震害特征、地壳构造活动性、震源机制、建筑物破坏的优势方向和介质条件,对这次地震的发震构造及其破裂方式作了初步探讨  相似文献   

4.
20 0 2年 1 2月 1 4日 2 1时 2 7分 ,在甘肃省河西走廊西端的酒西盆地南缘 ,玉门市西旱峡煤矿 -妖魔山一带发生了MS5 9破坏性地震 ,它是继 2 0 0 0年景泰 5 9级地震、2 0 0 1年 7月1 1日肃南祁青乡 5 3级地震后 ,在祁连山北缘发生的又一次破坏性地震。是中国大陆 2 0 0 2年度发生的最大一次地震 ,也是甘肃省遭遇的第一次现代化工业城市地震。整个玉门市震感强烈 ,部分建、构筑物 ,工业设施遭到不同程度的破坏或损坏。在现场考察的基础上 ,本文主要讨论本次地震的震害特征和发震断裂特征。1 主要震害及其特征1 1 震害及其类型本次地震造…  相似文献   

5.
赵平顺 《华南地震》2002,22(4):89-93
通过对1987年寻乌5.5级破坏性地震应急工作的回顾和总结。针对在此次地震应急工作中存在的问题和不足,提出在破坏性地震事件处理中改进有关工作的初步设想。以便提高各级政府及地震部门在破坏性地震发生时的应急处理能力。  相似文献   

6.
张瑞斌  达杰 《高原地震》2000,12(3):50-56
在杂多5.3级地震宏观烈度考察、划分的基础上,分析讨论了区域地震构造背景及发震构造,并对地震序列类型进行了划分。  相似文献   

7.
寻乌5.5级地震的灰色拓扑方法分析   总被引:1,自引:0,他引:1  
应用灰色拓扑方法对1987年8月2日的寻乌5.5级地震进行分析。按地震地质背景选取两组不同的源数据。建立了两个不同的时间函数即灰色预测模型。两组计算结果均预测1982年2月25日龙南地震后5.765-5.785年将再次发生中强地震,实际上间隔了5.430年发生了寻乌地震,相差小于0.36年。通过误差效验和外推检验,证实该方法对地震预测有较高的实用价值。对灰色拓扑方法用于地震分析预报。文中提出了一些值得注意的问题。  相似文献   

8.
1990年景泰6.2级强震的烈度分布及发震断裂   总被引:1,自引:0,他引:1  
1990年10月20日16时07分在甘肃省景泰、天祝、古浪三县交界处发生了一次6.2级强震。 现场考察结果表明:宏观震中位于下倘至大圈湾一带。地理位置为北纬37°07′,东经103°37.5′。震中烈度达Ⅷ度。极震区为一面积约20km~2,呈NWW向展布的椭圆形区域。在Ⅵ—Ⅷ度区圈定的基础上,本文对出现于Ⅶ度区内的Ⅷ度高烈度异常区的形成原因进行了初步讨论。并依据主震发生后的直接余震区、震中高烈度区、震源机制解、地面运动方向等资料得出这次地震是全新世以来活动强烈的老虎山断裂最新左旋运动的结果。  相似文献   

9.
1999年11月29日在辽宁海城岫岩交界处发生了5.6级地震,这次地震造成的破坏、震中烈度达到了Ⅶ度,本文阐述了这次地震的宏观地震参数,烈度划分标度,烈度分布及震害特点等内容,与一般的5.5级左右地震相比,这次地震的特点是,震害偏重,震害分布不均匀,地震波的频谱效应从震害现象得到明显反映。  相似文献   

10.
1936年灵山63/4级地震极震区烈度分布及发震构造   总被引:3,自引:0,他引:3  
李伟琦 《华南地震》1992,12(3):46-51
根据现场调查材料,对1936年4月1日广西灵山6 3/4级地震震中区烈度进行评定并绘制了等震线图。图中烈度Ⅸ、Ⅷ度区呈“T”形,两长轴方向与区内NEE及NNW方向断裂吻合。据此认为该震的发震构造为NEE和NNW两组断裂,6 3/4级地震系两组断裂共轭破裂的结果。又据低烈值沿NEE方向衰减较慢,认为NEE组断裂同时起控震构造作用。  相似文献   

11.
Strong ground acceleration seismic hazard in Greece and neighboring regions   总被引:1,自引:0,他引:1  
In an early paper [Tectonophysics 117 (1985) 259] seismic hazard in Greece was analyzed using a relatively homogeneous earthquake catalogue spanning 1900–1978 and a strong motion attenuation relationship adapted to use in Greece. Improved seismic hazard analyses are obtained here using Gumbel's asymptotic extreme value distribution applied to peak horizontal ground acceleration occurrence, but now taking into account the increased length and quality of earthquake catalogue data spanning 1900–1999 and the burgeoning information on earthquake strong motion data and attenuation relationships appropriate for Europe and, explicitly, Greece. Seismic acceleration hazard results tabulated for six cities reveal (e.g. using arbitrarily the 50-year p.g.a. with 90% probability of not being exceeded) changes of about 10% in the new calculated values: two cities show an increase and four a decrease. These are relatively small and reassuring adjustments.Inspection of the available attenuation relationships leads to a preference for the models of Theodulidis and Papazachos, particularly with the model modification to produce a ‘stiff soil’ site relationship, as these relationships explicitly exploit the Greek strong motion database. Isoacceleration maps are produced for Greece as a whole from each attenuation relationship inspected. The final set of maps based on the Theodulidis and Papazachos models provide a foundation for comparison with the Seismic Hazard Zones adopted in the New Greek Seismic Code where scope can be found to modify zone shape and the level at which p.g.a.s are set. It should be noted that the generation of the present isoacceleration maps is based on a seismogenic zone-free methodology, independent of any Euclidean zoning assumptions.  相似文献   

12.
This paper presents a methodological discussion of several issues involved with the development of maps of seismic hazard. The points made are illustrated with worked examples, using Scotland as an illustrative case. The issues treated are divided under three headings: matters relating to the difference between hazard maps and site studies; matters concerned with the technical issues of mapping, and matters relating to the use to which hazard maps will be put. It is concluded that a hazard map cannot be an all-purpose substitute for site-specific studies, owing to the impracticality of ensuring all-round conservatism in a hazard map, and the lower level of detail (more broad-brush approach) in a regional mapping study. Also, since users of a hazard map are not necessarily going to be engineers, consideration should be given to the provision of maps expressed in parameters other than physical measures of ground motion. Intensity is useful here, since it relates to actual earthquake experience and to damage. One can also move to making maps of generic seismic risk even before one has data on the distribution of exposure and vulnerability. Discussion is made of the issue of testing the validity of hazard maps against real experience, with examples. If a map can be shown to accord with real observations, then it can be treated with greater confidence by users.  相似文献   

13.
Recent earthquakes such as the MJMA 7.2 Hyogo-ken Nambu earthquake and the M 7.4 Kocaeli earthquake demonstrate once again the need to include detailed soil investigation into hazard evaluation, that is the need of microzonation. Seismic hazard assessment evaluated at a regional scale generally does not consider soil effects but only in a limited way using an attenuation law that can be ‘soft soil’ or ‘rock’. However, the relevant role of seismic hazard in the assessment of seismic coefficients for the definition of the actions in seismic codes must be properly considered. That is to say, the level of protection of buildings is proportional to a definite level of hazard (generally considered to be the ground motion with 10% probability of exceedence in 50 years). When a microzonation is performed, this criterion cannot be ignored, therefore, a clear linkage must be established between hazard (regional scale) and microzonation. The crucial point is represented by the reference motion (or input motion) to be used for site effects analysis, that must be compatible with the regional seismic hazard. In this paper, three different approaches for reference motion evaluation are analysed: probabilistic; stochastic; and deterministic. Through the case history of Fabriano microzonation the three approaches are compared. It is shown that each approach presents advantages and disadvantages with respect to the others. For example, the probabilistic approach (the reference motion is directly derived from the expected response spectra for a given return period) is linked with hazard, but produces an overestimation in short periods range, while the deterministic approach correctly simulates the wave propagation, but it ends with a kind of conditional probability. Until now, clear criteria to choose the right approach do not appear to exist and the expert experience is of fundamental importance.  相似文献   

14.
常想德  孙静  李帅 《中国地震》2017,33(4):771-780
通过对2017年8月9日精河6.6级地震灾区内共计355个调查点的实地调查,确定了此次地震的烈度分布。灾区最高烈度为Ⅷ度(8度),灾区面积15623km2,灾区总人口487696人,其中,受灾人口133695人,地震共造成36人受伤;对各烈度区内不同结构类型房屋的震害现象进行了整理,分析了不同结构类型房屋的抗震能力与震害原因,结果显示,土木结构房屋倒塌及屋檐塌落是导致人员受伤的主要原因;砖木结构房屋缺乏抗震设施,破坏形式多样;砖混结构房屋在高烈度区破坏较重;框架结构房屋主体完好但填充墙普遍出现破坏。安居富民房屋抗震性能良好。  相似文献   

15.
Seismic hazard assessment is carried out by utilizing deterministic approach to evaluate the maximum expected earthquake ground motions along the Western Coastal Province of Saudi Arabia. The analysis is accomplished by incorporating seismotectonic source model,determination of earthquake magnitude(Mmax), set of appropriate ground motion predictive equations(GMPE), and logic tree sequence. The logic tree sequence is built up to assign weight to ground motion scaling relationships. Contour maps of ground acceleration are generated at different spectral periods. These maps show that the largest ground motion values are emerged in northern and southern regions of the western coastal province in Saudi Arabia in comparison with the central region.  相似文献   

16.
1987年8月2日的寻乌5.5级地震,是建国以来江西境内发生的最大震级地震,通过对此次历史地震的回顾,归纳了江西省防震减灾工作发展过程及其经验。探讨了进一步推进工作的思路与措施。展望了江西省防震减灾工作的发展前景。  相似文献   

17.
Spatial sensitivity of seismic hazard results to different models with respect to background seismic activity and earthquake occurrence in time is investigated. For the contribution of background seismic activity to seismic hazard, background area source with uniform seismicity and spatially smoothed seismicity models are taken into consideration. For the contribution of faults, through characteristic earthquakes, both the memoryless Poisson and the time dependent renewal models are utilized. A case study, involving the assessment of seismic hazard for the Bursa province in Turkey, is conducted in order to examine quantitatively the influence of these models on seismic hazard results. The spatial variation of the difference in Peak Ground Acceleration (PGA) values obtained from these different models is presented in the form of difference maps for return periods of 475 and 2475 years. Best estimate seismic hazard maps for PGA and Spectral Accelerations (SA) at 0.2 and 1.0 s are obtained by using the logic tree method.  相似文献   

18.
郎从  伍国春  高孟潭 《中国地震》2014,30(3):324-329
本文利用GIS技术,将全国地震重点监视防御区(重防区)县级行政单元边界分别与中华人民共和国地震动峰值加速度图和中国及邻区地震区带和潜在震源区划分图叠加,对各县分别计算了如下4个地震危险性指标:(1)县境内最高地震动峰值加速度等级;(2)县境内面积比例最大的地震动峰值加速度等级;(3)县境内最高潜在震源区震级上限等级;(4)县境内面积比例最大的潜在震源区震级上限等级.通过分类统计全国重防区县级行政单元的地震危险性分布,得到的结论是:虽然同为重防区但各地的地震危险性相差巨大.据此,建议根据地震危险性的不同在重防区采取如下措施:第一,不论是何种类型的重防区,均应按中国地震动参数区划图对新建工程做抗震设防,对已有建筑做抗震加固;第二,位于高地震危险性的区域,特别是位于具7级以上潜在地震危险的重防区,要加强与防灾有关的应急准备、城市规划、地震监测预报、地震应急响应等专门措施.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号