云南地区强震前中小地震活跃—平静的定量计算

以累计频度定量计算方法 ,讨论了云南地区 1970年以来 ,各个强震孕震区的地震活动非线性度ZL值的时间进程曲线 ,系统计算了Ms≥ 6 3级强震前的ZL值曲线 ,结果表明 :强震前地震活动非线性度ZL值异常表现出的地震孕震区的地震平静—活跃或活跃—平静过程至少出现一次 ,且震例中的 83 %开始出现平静(活跃 )的时间为强震前 1～ 2 12 年 ,强震前半年左右结束出现活跃 (平静 )。     

粤闽地区水化学地震前兆异常特征分析

研究了粤闽两省及其近海近年来2次强震以及6个中等地震水化学前兆资料,结果表明,中等地震与强震的水化学前兆异常在数量上有着显著的差异,中等地震震前以中短期及短临异常变化为主,而强震前则超过三分之一的水化学测项出现持续1～4年的长趋势异常变化。同时研究表明,单凭水化异常出现的集中程度对未来震中作出预测是无统计依据的。     

共轭断层区中强震发震类型的预测和震型速判

在其轭断层区，中强震发生后是否会发生另一次中强震，这是中强震震后预测必然会碰到的问题。通过我国中强地震的余震时空分布特征的分析，研究了共轭断层区的地震类型以及震后震型速判问题。     

相继发生的三个强震的分布关系

本文从动态的观点出发,把时间上相继发生的三个7级以上强震(设它们分别为A、B和C事件)在空间上的分布关系作为主要研究内容。研究结果表明:(1)ABC所在平面的优势分布是切过软流圈的顶部或岩石圈的下部;(2)在地震A和B发生之后,地震C的优势分布是位于A,B连线的延伸部分和A,B之间稍近A的部位。根据A,B,C的分布关系,结合各地区的地质条件和历史地震资料等,我们可以从已知的两个7级以上强震预测第三个7级以上强震在各地区的发震概率大小     

我国大陆强震活动的韵律性特征

本文应用1895年以来我国大陆地区7级和大于7级的强震资料,讨论了我国大陆强震活动的轮回特性,指出了我国大陆地区强震高潮的到来有一个发展过程,即经历强震活动的平静、增强及出现强震高潮三个幕。文中讨论了各幕的持续时间及其强震活动的频度和能量分布,同时还分析了各轮回中强震的地区分布,探讨了每个强震高潮的主体活动区的形成特点。这些结果可为研究我国大陆强震高潮到来和结束的标志及判断未来强震高潮的主体活动地区等强震预测问题提供线索。此外,本文还分析了我国大陆强震高潮与东北深震的相关关系等问题     

中国大陆西部前兆异常涨落与强震短期预测研究

统计了1998年以来西部六省区(云南、 四川、 青海、 甘肃、 宁夏、 新疆)前兆异常月频次, 探讨了异常数量的涨落与强震活动的关系。 结果表明, 大部分强震前强震所在省份及邻区的前兆异常数量有明显的持续增长现象, 临震时一般表现为异常回落至低值。 从时间上看, 异常增长的起始时间一般为震前3～4个月到震前7～8个月, 少量为震前14～18个月; 异常数量到达峰值的时间为震前1个月至震前10个月。 研究认为, 异常月频次峰值时间可以作为强震预测的中短期至短期指标。 研究还表明, 2001年昆仑山口西8.1级地震前, 除青海、 甘肃地区外, 云南、 四川的前兆异常也突出, 似乎显示了8.1级地震的孕育范围已影响到川滇地区。     

旱涝变化用于川滇强震中期预报的统计研究

根据强震与震中区年降雨量的相关分析, 将川、滇两省划分成6个强震活动区.由此, 通过一种迭代算法, 又分别导出了6个 M6的强震活动区和川、滇两省 M7的强震的中期预报方程.      

闽粤海外的历史地震活动

闽粤海外地震集中分布于晚更新世以来活动最为强烈的近岸海域断裂靠近南澳和泉州的两个地段.1918和1906年南北两段分别发生过7.3和6.1级地震.笔者以这两次地震的仪器测定参数为准,通过宏观资料对比,参考地震背景,估定各早期地震的参数,编制了历史地震序列表.南、北两区地震活动基本同步,所记最大地震均在7.3级左右.大震以前,地震活动常有增强.主震后余震频繁,但强余震多发生在1至几年以后.15世纪晚期以来,出现过两次地震活动高潮:第一次在1600年前后,两区各发生43级以上地震8次,其中南区最强为6.7级,北区约7.5级;第二次在19世纪初,南区地震18次,最强达7.3级,北区仅6.1和5.5级地震各1次.1942年以来,整个地带极少中强震活动.究竟系减震作用影响,还是北区正在酝酿较强地震,值得深入研究.      

The Principles and Methods of Division of Potential Seismic Regions for Moderately Strong Earthquakes in Northeast and North China

The uncertainty of potential seismic regions for moderately strong earthquakes has a great effect on the results of seismic hazard analysis in weak seismicity regions,so it is the basement of seismic zoning and seismic hazard assessment for engineering sites by correctly dividing the potential seismic regions for moderately strong earthquakes.By taking Northeast and North China as examples,the authors compiled and systematically analyzed a large amount of basic data and then suggest the principles and methods of potential seismic regions for moderately strong earthquakes based on a great number of case studies.The practical division of potential seismic regions in the Changchun and Jilin areas shows that these principles and methods show better suitability.Moreover,the authors also discuss in this paper the progress obtained and put forward some problems that should be solved in the future.     

湖北西部地区小震活动与台湾强震关系研究

简要阐述了湖北西部地区地震活动和台湾地区强震活动特征, 研究了1981年以来湖北西部地区弱震和台湾地区6级以上强震发生的关系。 结果表明, 二个地区地震活动有较好的相关性。 根据这种相关性实现对台湾强震的临震预测, 对应率较高, 预报效能较好。     

河北邢台地震区外的小震丛集活动

1966年3月8日和22日河北省南部邢台地区发生TM6．8和M7．2大地震，之后，与其相邻的一些地区及由邢台地震引起的各烈度异常区也相继发生了小震活动。追述了邢台地震区附近的一些小震丛集活动序列，并对其活动特征进行了总结。     

Recognition of earthquake-prone areas: Methodology and analysis of the results

We present the results of verifying the areas that were detected as prone to strong earthquakes by the pattern recognition algorithms in different regions of the world with different levels of seismicity and, therefore, different threshold magnitudes demarcating the strong earthquakes. The analysis is based on the data presented in the catalog of the U.S. National Earthquake Information Center (NEIC) as of August 1, 2012. In each of the regions considered, we examined the locations of the epicenters of the strong earthquakes that occurred in the region after the publication of the corresponding result. There were 91 such earthquakes in total. The epicenters of 79 of these events (87%) fall in the recognized earthquake-prone areas, including 27 epicenters located in the areas where no strong earthquakes had ever been documented up to the time of publication of the result. Our analysis suggests that the results of the recognition of areas prone to strong earthquakes are reliable and that it is reasonable to use these results in the applications associated with the assessment of seismic risks. The comparison of the recognition for California with the analysis of seismicity of this region by the Discrete Perfect Sets (DPS) algorithm demonstrates the agreement between the results obtained by these two different methods.     

Histortical seismicity of the offshore Fujian-Guangdong region

The earthquakes offshore Fujian and Guangdong Provinces concentrated along the two segments near Nan’ao in the south and Quanzhou in the north of the off coast fault, which is very active since the late Pleistocene. In 1918 and 1906, two earthquakes with magnitudes 7.3 and 6.1 respectively occurred in the south and the north regions. With the instrumentally determined seismic parameters of these two earthquakes as standards, the author evaluated the parameters of the historical earthquakes by comparing their macroseismic materials with consideration of the geological background. As a result, chronological tables of historical earthquakes of the south and the north regions were compiled. The seismic activity of the two regions synchronized basically, and their strongest recorded earthquakes were both aroundM _s 7.3. Seismic activity usually intensified before the occurrence of strong events. Aftershocks were frequent, but strong aftershocks usually occurred one to several years after the main shock. Two high tides of seismic activity occurred since the late 15th century. Around 1600, eight earthquakes each with magnitudes over 4.3 occurred in both of the two regions. The magnitude of the strongest shock in the south region is 6.7, that in the north region is 7.5. The second high tide occurred at the early 20th century. Among the 18 earthquakes occurred in the south region, one was of magnitude 7.3; whilst only two earthquakes with magnitudes 6.1 and 5.5 respectively occurred in the north region. Further, medium to strong earthquakes never occurred since 1942. Whether this is the “mitigation effect” of strong shocks, or a big earthquake is brewing in the north region is worth intensive study. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 505–515, 1991. This work is supported by Chinese Joint Seismological Science Foundation.     

强烈地震孕育与发生的地点、时间及强度预测的思考与探讨

进入21世纪以来,全球范围内强烈地震频频发生,势已进入到一个新的地震活动时期.我国大陆内部、周边和台湾岛内一系列强烈地震(M_S≥6.5)的发生,特别是2008年5月12日汶川M_S8.0大地震的突发与其震前的异常平静表明:地表与上地壳均未见有明显的或确切能构成短、临强烈地震预测的浅表层活动过程,大地震由深部壳、幔物质运动,即深层动力过程所致.基于对强烈地震孕育、发生和发展的初步研究提出:(1)面对强烈地震的预测必须强化震源深部介质和构造环境的研究与探索,以达对未来地震发生地点的预测.(2)在地震强烈活动地区长期坚守介质破裂效应及其派生物理响应的井中观测,即"抚模"震源区介质与结构的动态"脉搏",以达对地震发生时间的逐步逼近或预测.(3)深入剖析强烈地震活动区、带、点的深、浅层空间结构与动力过程,历史地震在地震活动地域的纵向和横向的分布特征及可靠前兆信息的同步性经验和统计效应与发展态势,以对未来强烈地震发生强度的估计.这三个方面均必须以地壳深部信息的采集和研究为前提,是地震学和地震预测深化研究与探索的必经之途！     

南北带强震年度预测能力估计

对中国地震局原分析预报中心测震学科1988～1999年度划定的南北地震带强震(M≥7)危险区进行了回顾和分析。 结果表明, 从过程角度研究前兆地震活动图像及其演变是年度和中短期强震预测的有效途径, 这为南北地震带强震震情跟踪提供了条件。     

喀什-乌恰地区近年来强震活动平静的可能成因

通过分析喀什—乌恰地区和伽师—柯坪块区强震产生的静态库仑破裂应力变化(ΔCFS), 从断层相互作用和中等地震活动加、 减速特征的角度, 初步论证了两个区域强震活动交替发生特征的可能机理。 库仑破裂应力和加速矩释放模型拟合结果表明, 伽师—柯坪地区1997—1998年成组发生的伽师6级强震、 新疆南部周边发生的1992年苏萨梅尔M_S7.5地震和2005年巴基斯坦7.8级地震产生的静态应力变化不利于喀什—乌恰地区强震的发生, 可能使得该区后续强震的发生时间延迟了。 另一方面, 位于1992年苏萨梅尔M_S7.5地震和1997—2003年伽师系列强震产生的ΔCFS为负的喀什—乌恰地区地震活动表现为弱加速特征, 这或许是1993年以来喀什—乌恰地区强震平静特征的原因。 喀什—乌恰地区7级地震产生的正的ΔCFS可能有利于伽师—柯坪地区后续强震的发生, 3组7级地震产生的ΔCFS为正的区域内后续强震发生前均出现了一定程度的加速特征, 从而定量解释了喀什—乌恰地区强震活动对伽师—柯坪块区地震活动的影响。     

Estimating the validity of the recognition results of earthquake-prone areas using the ArcMap

In 1972, V. Keilis-Borok and I. Gelfand introduced the phenomenological approach based on the morphostructural zoning and pattern recognition for identification of earthquake-prone areas. This methodology identifies seismogenic nodes capable of generating strong earthquakes on the basis of geological, morphological, and geophysical data, which do not contain information on past seismicity. In the period 1972–2018, totally, 26 worldwide seismic regions have been studied and maps showing the recognized earthquake-prone areas in each region have been published. After that, 11 of these regions were hit by earthquakes of the relevant sizes. The goal of this work is to analyze the correlation of the post-publication events with seismogenic nodes defined in these 11 regions. The test was performed using the NEIC earthquake catalog because it uniformly defines the location and magnitudes of earthquakes over the globe. The ArcMap facilities were exploited to plot the post-publication events on the maps showing the recognized seismogenic nodes. We found that about 86% of such events fall in the recognized seismogenic nodes. The performed test proved the sufficient validity of the methodology for identifying areas capable of strong earthquakes and confirms the idea on nucleating strong earthquakes at the nodes.     

地震活动图像特征与强震危险区经验性预测依据的初步研究

在研究近期（10年）强震危险性判定和总结四川地区1972--2002年强震预测经验的基础上，清理了中国大陆1920--2002年47次浅源大震事件前地震活动图像特征（M≥4．7），提炼出10个方面12项经验性预测依据：主体活动区、多发时段、关联序列、大陆及地区地震异常图像、地区（带）-地段（震源区）地震增强图像（含信号震、诱发地震、地震条带）、相关地震、窗口地震、复发间隔、大陆及地区缺震、地段缺震与地段强震一缺震转折等。它们在47次震例中的综合出现率≥0．58（即依据比7／12以上）占42例；≥0．66（即8／12以上）占34例。因此，强震（M≥4．7）活动图像经验性预测依据可以作为预测有较大可能发生大地震危险区的依据之一。     

巴基斯坦曼塞赫拉7.8级地震对中国大陆大震趋势影响的初步研究

讨论了喜马拉雅弧型地震构造带西反射弧地带(简称“西触角区”),大地震活动的基本特征及2005年10月巴基斯坦曼塞赫拉7.8级地震发生后,对中国大陆地震趋势的可能影响。西触角区(N30~45°,E61~80°)大震活动存在显著的时间上10年左右成组性及两次大震时间间隔小于1个月的爆发性,地点上的成丛性,兴都库什深震区的地震有一定先兆意义,与东触角区(N20~29°,E95~102°)大地震也存在较好的相关性。沿欧亚大陆与印度洋、澳州板块碰撞带上印尼苏门答腊8.9级地震后,再次发生巴基斯坦7.8级大地震,显示出这一板缘地震带正处于活跃状态。研究认为未来1~2年应注意西触角区尤其是天山地震带的大震连发的危险性及东触角区(缅甸及川、滇为主)发生响应性大地震的可能性。对中国大陆内部其他地区大震形势的影响可能不大。