中原地区M_L 3.0地震高频异常与M_L 4.5以上地震时空特征分析     

谢健健  孙召华  贾漯昭  邢康  吴亚峰 《地震地磁观测与研究》2021,42(4):36-44

选取中原地区1970—2020年发生的983次M_L≥3.0地震,按季度、半年和全年统计地震频次,回溯检验各时段M_L≥3.0地震高频次异常与周边地区M_L 4.5地震的对应关系,得到以下结果：按照季度、半年和全年统计,3级地震高频次异常定量指标分别为5次、9次和18次,高频异常后1年内发生M_L≥4.5地震的概率分别为0.65、0.63和0.64,且R值计算结果表明,使用该方法预测地震具有一定可信度。将研究区以不同形式划分多种小区,进行3级地震高频次与M_L≥4.5地震震中空间相关性研究,发现在19次震例中,18次震例均可预估M_L≥4.5地震的发震区域,认为预测范围可由42平方度减小到21平方度,在少震弱震地区地震预测预报日常工作中,具有一定实用价值。  相似文献   

全球油气开采诱发地震的研究现状与对策     

张捷  况文欢  张雄  莫程康  张东晓 《地球与行星物理论评》2021,(3):239-265

人工诱发地震现象已经有很久的历史.水库蓄水、采矿、地热开发、从地下提取液体或气体,或将液体注入地球内部都可能诱发地震.大量地震监测数据与科学分析结果显示:美国俄克拉何马州的地震剧增主要与页岩油气开采的废水回注量相关;加拿大阿尔伯塔省的地震剧增主要与页岩油气开采水力压裂的工作量相关;而荷兰罗宁根天然气田的传统天然气开采也同样诱发了较强的地震活动.在中国四川盆地的页岩油气开发区域,地震活动近几年也大幅度增强,但目前监测与科研工作较少,对某些地震成因尚有争议.目前研究诱发地震问题已成为学术界与工业界的一门专业学科.推断诱发地震,除了分析时空分布与工业活动的相关性之外,本文综述了该领域基于地震学、地质动力学、构造地质学的多种分析方法.如何在油气开采过程中减少诱发地震的灾害影响成为当前相关各界极为关注的科研问题,本文介绍了多个国家或地区建立的控制诱发地震的管理系统、基于地震大数据的诱发地震概率预测方法,以及基于地球物理与地质信息的综合诱发地震风险评估方法,并对我国控制诱发地震问题提出建设性意见.  相似文献   

青藏高原东北隅弧形构造区现代中小地震密集区与历史强震的关系探讨          下载免费PDF全文

文亚猛  袁道阳  张波  冯建刚 《地震工程学报》2021,43(3):594-606

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   

2021年青海玛多7.4级地震前地震活动异常特征分析   总被引：1，自引：1，他引：0       下载免费PDF全文

张博  李敏娟 《地震工程学报》2021,43(4):826-833

结合青海玛多7.4级地震前日常跟踪工作中出现的地震活动异常,系统梳理羌塘块体6级地震成组、中国大陆5级地震低频活动、青藏高原东北缘中等地震活动显著增强以及青藏高原东北缘地区震群活动的时空异常特征,总结多项指标的预测意义,并对部分重要指标做了预测效能评估。同时,通过研究碌曲震群的时空分布特征,认为碌曲地区是一个应力敏感区域,对周边地区中强地震的发生有较好的预测意义,在后续震情监视过程中应该作为重要指标来跟踪。  相似文献   

利用区域大气静电场监测网临震预估地震灾害   总被引：6，自引：0，他引：6  

陈涛  张效信  张学民  靳小兵  吴晗  提烁  李仁康  李磊  王诗涵 《地球物理学报》2021,64(4):1145-1154

本文通过震例研究提出一种临震前形成晴天大气静电信号异常的物理机制.在大震临震阶段,震中区域附近地壳结构发生临界变化,产生大量的岩石微破碎,岩缝间的通道很可能相互连通起来,并通过土壤缝隙,将包含微量元素的气体释放到空中,其中放射性同位素在弥散到空中的过程中不断产生衰变,特别是产生α粒子的放射性电离辐射.这使得大气充满异常多的正负离子,这些异常多的正负离子可能会产生与晴天大气相反的极化电场并被仪器监测到.本文提出了利用这种晴天大气异常静电信号来评估灾害性大震事件发生的组网监测方法,以及确定潜在震中位置、震级大小和发震时段的技术思路.  相似文献   

Spatiotemporal seismic hazard and risk assessment of M9.0 megathrust earthquake sequences of wood‐frame houses in Victoria,British Columbia,Canada     

Lizhong Zhang  Katsuichiro Goda  Maximilian J. Werner  Solomon Tesfamariam 《地震工程与结构动力学》2021,50(1):6-25

Megathrust earthquake sequences, comprising mainshocks and triggered aftershocks along the subduction interface and in the overriding crust, can impact multiple buildings and infrastructure in a city. The time between the mainshocks and aftershocks usually is too short to retrofit the structures; therefore, moderate‐size aftershocks can cause additional damage. To have a better understanding of the impact of aftershocks on city‐wide seismic risk assessment, a new simulation framework of spatiotemporal seismic hazard and risk assessment of future M9.0 sequences in the Cascadia subduction zone is developed. The simulation framework consists of an epidemic‐type aftershock sequence (ETAS) model, ground‐motion model, and state‐dependent seismic fragility model. The spatiotemporal ETAS model is modified to characterise aftershocks of large and anisotropic M9.0 mainshock ruptures. To account for damage accumulation of wood‐frame houses due to aftershocks in Victoria, British Columbia, Canada, state‐dependent fragility curves are implemented. The new simulation framework can be used for quasi‐real‐time aftershock hazard and risk assessments and city‐wide post‐event risk management.  相似文献   

The influence of earthquakes on the Chandler wobble during 1977–1983     

Richard S. Gross 《Geophysical Journal International》1986,85(1):161-177

Summary. A direct calculation is made of the effect on the Chandler wobble of 1287 earthquakes that occurred during 1977–1983. The hypocentral parameters (location and origin time) and the moment tensor representation of the best point source for each earthquake as determined by the 'centroidmoment tensor' technique were used to calculate the change in the Chandler wobble's excitation function by assuming this change is due solely to the static deformation field generated by that earthquake. The resulting theoretical earthquake excitation function is compared with the 'observed' excitation function that is obtained by deconvolving a Chandler wobble time series derived from LAGEOS polar motion data. Since only 7 years of data are available for analysis it is not possible to resolve the Chandler band and determine whether or not the theoretical earthquake excitation function derived here is coherent and in phase with the 'observed' excitation function in that band. However, since the power spectrum of the earthquake excitation function is about 56 dB less than that of the 'observed' excitation function at frequencies near the Chandler frequency, it is concluded that earthquakes, via their static deformation field, have had a negligible influence on the Chandler wobble during 1977–1983. However, fault creep or any type of aseismic slip that occurs on a time-scale much less than the period of the Chandler wobble could have an important (and still unmodelled) effect on the Chandler wobble.  相似文献   

Seismicity and present-day tectonics of the Svalbard region     

B. J. Mitchell  H. Bungum  W. W. Chan  P. B. Mitchell 《Geophysical Journal International》1990,102(1):139-149

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On the linear relation between m_b and M_s for discrimination between explosions and earthquakes     

All A. Nowroozi 《Geophysical Journal International》1986,86(2):687-699

Summary. The statistical capability of the m _b: M _s discriminant for the discrimination of earthquake and explosion populations is examined by application of discriminant functions to a group of 83 explosions and 72 earthquakes in Eurasia. Equations are derived for the probability that an event is an earthquake or an explosion. The positive sign of DIS in the decision index equation, DIS _i = 34.3383 – 11.9569 mb _t + 7.1161 M _si , indicates that the event i is an earthquake. Its negative sign indicates that event i is an explosion. The probability of correct classification for an event, P _i , is related to its DIS _i value, by P _i = [1-exp (DIS _i )]⁻¹, where a large, positive DIS indicates a high probability that an event is an earthquake and a large, negative DIS indicates a high probability that an event is an explosion. The discrimination line M _s = 1.680 m _b– 4.825, or m _b= 0.595 M _s+ 2.872 very successfully separates the explosion population from the earthquake population. The points on this line have an equal chance of being an earthquake or an explosion; moreover, for any event, the distance parallel to the M _s-axis from the point representing that event in the m _b: M _s plane to this line is a measure of the probability for the correct classification of that event.  相似文献   

Coda Q In the Eastern Caribbean, West Indies   总被引：1，自引：0，他引：1  

W. B. Ambeh  L. L. Lynch 《Geophysical Journal International》1993,112(3):507-516

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