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1.
20 0 3年 5月 2 1日当地时间 1 9时 4 4分 ,在阿尔及利亚宰穆里以北 ( 37 1°N ,3 9°E)发生里氏 6 9级地震 ,造成巨大的财产损失和人员伤亡。震后先后有 32个国家派出地震灾害紧急救援队到灾害现场进行紧急救援活动。中国国际救援队首次赴国外实行国际人道主义救援工作 ,其反应速度、现场救援的表现、救援后期的医疗救助和建筑物受灾情况鉴定等工作受到联合国和阿尔及利亚政府和人民的充分肯定。中国国际地震救援队除在地震现场从事紧张的地震救生任务外 ,随队的地震专家还与阿尔及利亚同行就这次地震的地震活动、发震构造和地震监测等方…  相似文献   

2.
魏若平 《内陆地震》1990,4(1):79-86
地震发生后,首先是尽早地判断震型,以判断未来大震发生的可能性及地震活动的发展趋势。本文对1970—1987年新疆大部分中强地震的序列进行了震型判断和震型的早期判断,以求找出新疆地震序列类型的判断指标,为快速判定震型,预报震后序列发展趋势提供依据,并通过震型判断的分析研究找出新疆地震序列类型的基本特征。  相似文献   

3.
收集和统计了2008年汶川MS8.0地震、2010年玉树MS7.1地震和2013年芦山MS7.0、岷县MS6.6地震引起的中国大陆井水温同震响应现象,分析了其特征。结果显示:这4次地震对中国大陆地下流体影响显著,井水温同震响应特征有很大差异,后三次水温同震响应范围、幅度和持续时间远不及汶川地震,即使震级相差不大的玉树和芦山地震,同震响应的特征也不尽相同。最后探讨了这种现象的成因机理。  相似文献   

4.
李莹甄  赵翠萍 《内陆地震》2003,17(4):309-316
分析了2003年2月14日石河子5.4级地震前北天山地震活动图像和地震学参数异常过程。5.4级地震发生在2002年北天山4级地震集中活动区空段,震前12项地震学参数时间进程存在中、短期异常,3项地震波参数出现短期异常。震前3个月乌鲁木齐震情窗出现超警戒线异常。震前10天震中附近地区地震和震群活动显著。  相似文献   

5.
2006年6月21日甘肃文县5.0级地震的地震序列余震发育,判定为主震-余震型。之前该地区100多年中强地震平静;震前一年ML3.0以上地震频次增高、地震连发;震前一月ML3.0地震活动平静。没有孕震空区和条带存在。  相似文献   

6.
总结了1993年1月27日普洱6.3级地震前的地震活动特征和余震序列特征。发再震前一年,震中区及其所在的思茅、普洱地震带地震活动平衡,而与其相邻的耿马、澜沧震带地震活动增强,表现出与该地区往中强震之前不同的地震活动特点。余震序列各项参数则表现主余震型的典型特征。  相似文献   

7.
收集了昆明地震台2001~2004年数字地震仪记录的从地方震到极远震、浅源地震到深源地震共计351个典型地震,用分析软件进行震相标注后,采用数据库、前端显示和查询相结合的电子版形式,编制成<昆明台数字地震仪震相分析图集>.  相似文献   

8.
2020年7月12日唐山5.1级地震分析   总被引:2,自引:1,他引:1       下载免费PDF全文
王想  周依  陈婷  王时  李小军 《地震工程学报》2021,43(6):1280-1287
对2020年7月12日唐山5.1级地震的发震特点、地震的性质、发震构造以及破裂机制进行初步分析,推测唐山断裂可能为其控震断裂。地震前唐山地区和震中所处的华北构造区的地震活动性异常以缺震和显著平静为主,表明该区域地壳应力积累到了一定程度。分析认为:此次唐山5.1级地震属于1976年7月28日唐山7.8级大震震区内的地震起伏活动;此次地震的序列本身并不丰富,震区烈度偏低、有感范围大。  相似文献   

9.
大同和张北地震震前地震活动异常对比研究   总被引:1,自引:0,他引:1  
吕晓健  高战武  吴昊 《地震》2004,24(4):106-112
对1989年大同6.1级地震和1998年张北6.2级地震前, 华北地区以及震中附近出现的长、 中、 短期地震活动异常进行了研究, 结果表明, 二次地震前有较多相似的地震活动异常出现, 并且异常的空间位置也相似。 分析认为,产生这些相似异常现象的原因是由于二次地震的孕育都与山西断陷带和张家口-渤海断裂带活动有关。 震前短期阶段多次出现小震活动沿断裂带有序分布, 表明强震前孕震构造控震能力增强。  相似文献   

10.
基于《中国震例》(1970—2013年), 系统清理了246次M≥5.0震例前的地震活动图像异常, 并结合区域差异进行地震空区和地震条带的统计特征研究。 结果显示: ① 在246次震例中, 震前出现地震空区、 地震条带的震例数分别为105次、 51次, 占震例总数的42.7%和20.7%; ② 随着主震震级的增大, 地震空区和地震条带出现的比例逐渐增大, 尤其是7级以上地震, 震前出现地震空区的震例数占同类震例总数的83.3%, 出现地震条带的震例数占同类震例总数的66.7%, 可见地震空区和地震条带可能是7级以上强震的重要异常判据; ③ 针对整个中国大陆及近海, 地震空区和地震条带的持续时间、 展布尺度、 起始震级与主震震级存在一定线性关系, 相关系数能够通过95%置信水平的阈值检验; ④ 各主要构造分区的统计结果差异较大, 青藏高原北部除地震空区持续时间外, 其余地震空区和地震条带参数与主震震级之间的线性关系均通过阈值检验, 南北带中南段和华北地区有个别参数通过检验, 天山地区所有参数均未通过检验。  相似文献   

11.
The occurrence of the Algiers earthquake (M 6.8) of May 21, 2003, has motivated the necessity to reassess the probabilistic seismic hazard of northern Algeria. The fact that this destructive earthquake took place in an area where there was no evidence of previous significant earthquakes, neither instrumental nor historical, strongly encourages us to review the seismic hazard map of this region. Recently, the probabilistic seismic hazard of northern Algeria was computed using the spatially smoothed seismicity methodology. The catalog used in the previous computation was updated for this review, and not only includes information until June 2003, but also considers a recent re-evaluation of several historical earthquakes. In this paper, the same methodology and seismicity models are utilized in an effort to compare this methodology against an improved and updated seismic catalog. The largest mean peak ground acceleration (PGA) values are obtained in northernmost Algeria, specifically in the central area of the Tell Atlas. These values are of the order of 0.48 g for a return period of 475 years. In the City of Algiers, the capital of Algeria, and approximately 50 km from the reported epicenter of this latest destructive earthquake, a new mean PGA value of 0.23 g is obtained for the same return period. This value is 0.07 g greater than that obtained in the previous computation. In general, we receive greater seismic hazard results in the surrounding area of Algiers, especially to the southwest. The main reason is not this recent earthquake by itself, but the significant increase in the mmax magnitude in the seismic source where the city and the epicenter are included.  相似文献   

12.
2003年5月22日阿尔及利亚Ms6.9级地震发生,笔者参加了震后救援工作和科考工作。本文介绍和分析了阿尔及利亚的结构特点及其破坏特征,且较为深入地分析了其破坏的原因。以此为鉴,初步分析了我国闽南地区房屋结构的整体抗震能力,提出应对之策以防患于未然。  相似文献   

13.
李成龙  张景发 《地震》2013,33(2):103-108
本文详细介绍了基于主成分分析的变化检测方法, 根据地震应急工作的实际要求设计合理的变化检测流程, 以阿尔及利亚地震QuickBird震前震后影像为试验数据, 使用该方法对地震引起的建筑物倒塌进行变化检测应用。 结果证明设计的变化检测方法流程具有一定的实用性, 能较为准确地标示出震后损毁区域, 是对变化检测技术应用于地震应急工作的有益尝试。  相似文献   

14.
Seismotectonic zonation studies in the Tell Atlas of Algeria, a branch of the Africa-Eurasia plate boundary, provide a valuable input for deterministic seismic hazard calculations. We delineate a number of seismogenic zones from causal relationships established between geological structures and earthquakes and compile a working seismic catalogue mainly from readily available sources. To this catalogue, for a most rational and best-justified hazard analysis, we add estimates of earthquake size translated from active faulting characteristics. We assess the regional seismic hazard using a deterministic procedure based on the computation of complete synthetic seismograms (up to 1 Hz) by the modal summation technique. As a result, we generate seismic hazard maps of maximum velocity, maximum displacement, and design ground acceleration that blend information from geology, historical seismicity and observational seismology, leading to better estimates of the earthquake hazard throughout northern Algeria. Our analysis and the resulting maps illustrate how different the estimate of seismic hazard is based primarily on combined geologic and seismological data with respect to the one for which only information from earthquake catalogues has been used.  相似文献   

15.
为了总结在阿尔及利亚地震救援工作中存在的问题和经验教训,联合国人道主义事务办公室于2003年9月9~10日在瑞士日内瓦举行了“阿尔及利亚地震救援经验工作会议”。来自参加过地震救援的部分国家、阿尔及利亚和有关国际机构的代表共93人参加了会议。文章介绍了会议讨论的问题,包括灾害初期预警、动员和救援队的部署;现场协调;搜救工作和使用指南。最后,针对我国国际救援队的工作,提出具体建议。  相似文献   

16.
Seismicity in the Eastern Tellian Atlas of Algeria is active of moderate to low magnitude. The direct identification of active fault is often a difficult task. In fact, in this region, despite the intense seismicity, only the Constantine earthquake of 27 October, 1985 ( M s = 5.7) and the Kherrata earthquake of 17 February, 1949 ( M s = 4.7), have generated surface ruptures. Hence, the integration of both geological, historical and instrumental seismic data are important in order to characterise the most important seismogenic structures. This paper presents a preliminary overview of the identified neotectonic faults that we consider active in the Eastern Tellian Atlas of Algeria. Thus, seismicity and neotectonic maps are presented and the faults which are active or potentially active from a neotectonic point of view are shown in relation with the main seismic groupings. This study based mainly on available seismic and bibliographic data and several unpublished marine seismic data enable us to suspect a fault as the eventual source of the Jijeli earthquake of 21 August 1856 that destroyed the Jijeli town and its surroundings. The results inferred from this work represent a starting point for more detailed studies in seismogenic areas.  相似文献   

17.
The plate dynamics in the central western Mediterranean region is characterised by a collision between the Eurasian and African plates. In response to this dynamics, many systems of faults and folds having a NE-SW and E-W trending have been generated along the Tellian Atlas of Algeria. The Oranie region (north western Algeria) has experienced some significant earthquakes in the last centuries, the most important one is that of Oran city on February 9th 1790, Io = XI which destroyed the town completely and caused the loss of many lives. Since 1790 no other event was so disastrous except that of August 18th 1994, Mw = 5.7, which struck Mascara province (Algeria) at 01 h 13 mn GMT. Since the beginning of this century the region has been dominated by a seismic quietness. Thus, no event with magnitude larger than 5.5 have occurred in this area. In relation with this recent event, a seismotectonic framework summarising the tectonic, seismicity and focal solution results is presented. The Maximum Observed Intensities Map (MOI) made for Algeria (Bezzeghoud et al., 1996) is also used to show that the Mascara region is located in an VIII-X intensity zone, which explain partially the casualties caused by the 18/08/1994 (Mw = 5.7) earthquake. This earthquake is not anomalous compared to historical records but is unusual compared to recorded seismicity of this century. The seismotectonic map made in this study and also the review of the focal solutions given by the EMSC, Harvard, and other authors shows that our event is probably associated with a source belonging to a system of faults located in the vicinity of the village of Hacine where the maximum damage was observed.  相似文献   

18.
This paper deals with the dynamic behaviour of pin-jointed, steel-framed buildings which derive stiffness from bracing and cladding, and their response to earthquake loading. The first part of the paper considers the best way to obtain an analytical model, using the natural frequencies and mode-shapes measured on a CLASP building in Nottingham employing eccentric-mass vibrators. The second part is a study of a key section of a CLASP hospital now under construction in Algeria, in which the earthquake-induced forces in the bracing are calculated. The final part is concerned with studies on two-storey and three-storey CLASP-type models, using different bracing arrangements.  相似文献   

19.
The October 27, 1985 Constantine earthquake of magnitude MS 5.9 (NEIC) although moderate is the strongest earthquake recorded in the eastern Tellian Atlas (northeast Algeria) since the beginning of instrumental seismology. The main shock locations given by different institutions are scattered and up to 10 km away northwest from the NE–SW 30 km long elongated aftershocks cloud localized by a dedicated temporary portable network. The focal mechanism indicates left-lateral strike-slip on an almost vertical fault with a small reverse component on the northwest dipping plane. This paper presents relocations of the main shock and aftershocks using TomoDD. One hundred thirty-eight individual focal mechanisms have been built allowing the determination of the stress tensor at different scales. A rupture model has been suggested, which explains the different observations of aftershock distribution and stress tensor rotation.  相似文献   

20.
On March 20, 2006, a moderate-magnitude earthquake of Mw 5.2 hit the region of the Babors mountains, a region located two hundred km east of Algiers (capital of Algeria). More precisely, the epicentre occurred 40 km south-east of Béjaïa, the second most important city in the Kabylian region. The earthquake impacted an area with a radius of about 70 km and caused the death of four persons and injured 68. Damage was mainly observed in Lâalam village (district of Kherrata) where some buildings and old houses were affected. Damage was mainly due to a moderate landslide triggered by the earthquake. Rock falls were also observed near the main cliffs. The maximum observed intensity I0 was estimated to VII (EMS-98 scale). According to the main shock focal mechanism solution and the spatial distribution of aftershocks, the main shock was reliably found to have been generated by an NS sinistral strike-slip fault. The compressive stress axis σ1, oriented N325, is in agreement with the direction of convergence between Eurasia and Africa.  相似文献   

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