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我国37年来在地震中殉难的约27万多人.这个数字是国家地震局局长安启元在今天召开的中国地震工作20年学术交流与表彰会上披露的.他说,地震科学研究必须紧密围绕地震预报这项中心工作.自邢台地震以来,由于把减轻地震灾害作为科研任务的根本方向,1975年曾经成功地预报了海城地震,使10万余人免于丧生,成为世界地震科学史上第一次取得实效的预报实践.但是,限于目前还不能充分认识地震规律,从而导致我国在唐山地震预报中出现重大 相似文献
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1987年3月18日零点在河北省临城县的黑城镇附近发生了一次M_L3.7级的地震,当地有明显的感觉。在此之前从1986年2月以来这里就有微震活动,迄今已有100余次。 8月21日黄壁庄水库北侧十来公里的灵寿县东城南,南城东、白狗台、故城等村庄附近又突然发生一次M_L4.5级地震,当地听到震时有响声,房屋产生不同程度的裂缝,列25日为止,这里共发生70余次小震。 1966年邢台地震后,南自河南林县,向北经磁县、沙河、邢台。内邱、临城、柏乡、高邑、井陉、获鹿、灵寿行唐等太行山东麓各县均先后发生大小不等的一些地震。这一带的地震活动在时间上有一定的集中性,而且发生地 相似文献
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关于地震文献信息系统整体化建设的思考与构想随着地震科学研究和事业的发展。地震科技文献量逐年递增,所涉及的门类众多,跨学科、多主题、相互交叉的文献信息大量产生,加上其价格呈指数上涨,对我们地震文献信息部门构成了巨大的外部压力。而在地震文献信息系统内部,... 相似文献
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抓住邢台地震不放的三十年 总被引:1,自引:0,他引:1
为纪念邢台地震30周年,唐山地震20周年,笔者回顾了在邢台现场十多年工作中对敬爱的周恩来总理亲切号召的体会和许多 重要指示的理解及所走过的科研里程及在地震预报研究中诸多概念的提出和进展,都是在总理精神鼓舞下,强烈的责任感趋势下得到的。 相似文献
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Three dimensional viscoelastic simulation on dynamic evolution of stress field in North China induced by the 1966 Xingtai earthquake 总被引:1,自引:0,他引:1
Introduction Among the mechanisms of earthquake, the essentials may be that the earthquake is a dynamic process of energy accumulation, reaching critical status and failure in focal region. Some nonlin-ear mechanical studies (Bak, Tang, 1989; Ito, Matsuzaki, 1990) show that earthquakes as a self-organized critical phenomenon may be induced by relative small stress disturbance. WANG, et al (1980) already carried out the numerical simulation on earthquake migration in the beginning of 1980s. … 相似文献
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THE SOURCE PARAMETERS AND SEISMOTECTONIC IMPLICATIONS OF THE SEPTEMBER 4, 2017 ML4.4 LINCHENG EARTHQUAKE
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LI He XIE Zu-jun WANG Yi-xi WANG Xiao-shan DONG Yi-bing ZHANG Hui PENG Zhao LIU Wen-bing GAO Ye WANG Li-xia 《地震地质》2019,41(3):670-689
At 3:05, September 4, 2017, an ML4.4 earthquake occurred in Lincheng County, Xingtai City, Hebei Province, which was felt obviously by surrounding areas. Approximately 60km away from the hypocenter of Xingtai MS7.2 earthquake in 1966, this event is the most noticeable earthquake in this area in recent years. On the one hand, people are still shocked by the 1966 Xingtai earthquake that caused huge disaster, on the other hand, Lincheng County is lack of strong earthquakes. Therefore, this quake has aroused widespread concerns by the government, society and seismologists. It is necessary to clarify whether the seismogenic structure of this event is consistent with the previous seismicity and whether it has any new implications for the seismic activity and seismic hazard in this region. Therefore, it is of great significance to study its seismogenic mechanism for understanding the earthquake activity in Xingtai region where a MS7.2 earthquake had occurred in 1966.
In this study, the Lincheng earthquake and its aftershocks are relocated using the multi-step locating method, and the focal mechanism and focal depth are determined by the "generalized Cut and Paste"(gCAP)method. The reliability of the results is analyzed based on the data of Hebei regional seismic network. In order to better constrain the focal depth, the depth phase sPL fitting method is applied to the relocation of focal depth. The inversion and constraint results show that aftershocks are mainly distributed along NE direction and dip to SE direction as revealed by depth profiles. Focal depths of aftershocks are concentrated in the depths of 6.5~8.2km with an average of about 7km. The best double-couple solution of the mainshock is 276°, 69° and -40° for strike, dip and slip angle for nodal plane I and 23°, 53° and -153° for nodal plane Ⅱ, respectively, revealing that it is a strike-slip event with a small amount of normal-fault component. The initial rupture depth of mainshock is about 7.5km obtained by the relocation while the centroid depth is 6km derived from gCAP method which was also verified by the seismic depth phase sPL observed by several stations, indicating the earthquake is ruptured from deep to shallow. Combined with the research results on regional geological structure and the seismic sequence relocation results, it is concluded that the nodal plane Ⅱ is the seismogenic fault plane of this earthquake.
There are several active faults around the hypocenter of Lincheng earthquake sequence, however, none of the known faults on the current understanding is completely consistent with the seismogenic fault. To determine the seismogenic mechanism, the lucubrated research of the MS7.2 Xingtai earthquake in 1966 could provide a powerful reference. The seismic tectonic characteristics of the 1966 Xingtai earthquake sequence could be summarized as follows:There are tensional fault in the shallow crust and steep dip hidden fault in the middle and lower crust, however, the two faults are not connected but separated by the shear slip surfaces which are widely distributed in the middle crust; the seismic source is located between the hidden fault in the lower crust and the extensional fault in the upper crust; the earthquake began to rupture in the deep dip fault in the mid-lower crust and then ruptured upward to the extensional fault in the shallow crust, and the two fault systems were broken successively. From the earthquake rupture revealed by the seismic sequence location, the Lincheng earthquake also has the semblable feature of rupturing from deep to shallow. However, due to the much smaller magnitude of this event than that of the 1966 earthquake, the accumulated stress was not high enough to tear the fracture of the detachment surface whose existence in Lincheng region was confirmed clearly by the results of Lincheng-Julu deep reflection seismology and reach to the shallower fault. Therefore, by the revelation of the seismogenic mechanism of the 1966 Xingtai earthquake, the seismogenic fault of Lincheng earthquake is presumed to be a concealed fault possessing a potential of both strike-slip and small normal faulting component and located below the detachment surface in Lincheng area. The tectonic significance indicated by this earthquake is that the event was a stress adjustment of the deep fault and did not lead to the rupture of the shallow fault. Therefore, this area still has potential seismic hazard to a certain extent. 相似文献
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利用三维粘弹性有限元模型,首先研究了1966年3月22日邢台7.2级地震所引起的库仑破裂应力的震时变化,以及百年时间尺度流变效应的动态演化图象及其特征,然后模拟了自该地震开始,经过1976年7月28日唐山7.8级地震,直到1980年的15年间,两次7级以上强地震对华北地区应力场的震时扰动作用及其引起的1年时间尺度的库仑破裂应力的动态变化速率,探讨了一次强地震对潜在的下一次强地震可能的加速触发作用. 相似文献
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邢台地震孕育发生模型及其前兆机理探讨 总被引:10,自引:0,他引:10
根据人工地震与天然地震测深成果,提出了邢台地震孕育发生的概念模型。根据这个模型,分析了邢台地震前震区应力分布图像与发展过程、结合深部构造特征,探讨了邢台地震的成核过程,进而讨论了邢台地震的直接前震,地形变,地下水位三项主要前兆的形成机制。 相似文献
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ANALYSIS ON STRUCTURAL FEATURES:INSIGHTS FROM SATELLITE-DERIVED GRAVITY MODEL AND SEISMIC PATTERN
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In this paper, based on a large number of cumulative observational data from the seismic monitoring network in China, we grid the research area to calculate the density values at each grid node and convert the qualitative earthquake epicenter distribution to quantitative seismic pattern. Minimum magnitude of completeness(MC)is determined by magnitude-rank analysis, which provides lower limit earthquake and original time. New satellite-derived gravity model v23.1, which is based on satellites CryoSat-2 and Jason-1 data, is used to determine the Bouguer gravity anomaly derived from free-air gravity anomaly and elevation database sets SRTM30, and ultimately, the complete Bouguer correction is obtained. In this paper, the Xingtai earthquake zone and Tanlu fault zone (Anhui segment) are selected for case study. Bouguer gravity anomaly presents a NE-trending U-shaped narrow strip in the Xingtai earthquake zone, and its location is consistent with Shulu Fault Basin. Grid density value contours are restricted by the U-shaped strip, and the extreme value of seismic activity density lies in the bottom of the U-shaped strip as shown in the cross section. The results of Bouguer gravity anomaly and upward continuations to the different heights show good linearity and gradient in the Tanlu fault zone (Anhui segment); and both long-axis direction of seismic pattern and nodal plane strike of seismogenic fault from focal mechanism solutions trend NNE. In short, the Tanlu fault zone(Anhui segment)is a large deep-seated fault that still has the ability to control seismic activity along it. Based on the measured gravity and magmatic data, using the edge detection TDX method to interpret the concealed boundary of the Anqing M4.8 earthquake near the Tanlu fault, and combining with the results from deep seismic reflection profiles of the study area, we discussed the causative fault of the Anqing earthquake. 相似文献
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防震减灾事业的长期可持续发展取决于地震科技进步,而制定好地震科技发展规划是推动地震科技进步的重要保障。本文建议了地震科技发展战略制定应考虑的5个原则,提出当前和今后一段时期地震科技发展战略的构想,从11个方面提出了“十一五”地震科技项目建议,同时,对其中地震预报科学实验场的选择提出了原则建议,进而从科学意义与必要性、已具备的条件、科学目标、监测与研究内容和运行机制与模式等5个方面论述了祁连山大震机理与预报科学实验场建设的可行性。 相似文献
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1966~1976年华北的邢台大震、渤海大震以及唐山大震皆可由以29 a为周期的三性分布求出其发震年份.至于发震地区可由"静中动判据"求出是唐山地区和渤海莱州湾地区.邢台大震的位置可由立交模式来推求.1966~1976年这次大震高潮后由三性分布后延推知在2016~2017年华北可能会再次发生7级以上大震. 相似文献