地震间隙图像与地震大趋势

分析了几个区域的地震间隙图像特征及其与地震大形势的关系。本世纪６０年代前全球 历了大震活跃期,地震间隙基本保持平稳均匀分布,之后活动减弱、转平静。     

1988年四川八美5级地震参数和前兆的研究

本文对1988年6月四川省道孚八美(即乾宁)4.5、5.0、4.0级地震前后地震活动进行了研究,给出了地震参数、P波初动解、余震序列和前兆变化的分析及未来地震危险性的讨论。     

大地震前的“震情三分律”

本文主要根据地震学理论和六十年代中期以来我国多震区Ms≥6.0级大震前小震活动频度增高异常的震兆图象,分析研究了其涨落峰、谷间的时间分布特点与大震发生时间的关系,提出了大震前的“震情三分律”方法。并进行了回顾性预报应用检验,同时还指出“前兆三分律”现象。     

青海省兴海7.0级地震前兆

介绍了青海省兴海７．０级地震前水氡，地下水位，地表形变，地震活动性，气象及动物等出现的异常，并对震前的预报作了简介。     

1969年渤海7.4级大震前后的区域地震活动图象

分析与总结了１９６９年渤海Ｍ７．４大震前后地震活动图象特征,包括大震序列的时空分布及前兆地震活动图象特征、大震等距迁移、主要间隔缩短、共轭断层蠕滑、小震成带、诱发前震现象,地震触发响应系数异常十分显著。指出地震相互作用和自组织性为中长期地震预报提供了可能。     

土耳其地震灾害及地震工作概况

概述了１９９８年６月２８日土耳其南部６．３级强烈地震,在地震中,共有１４４人死亡,１５００多人受伤,５０００多座楼房遭受不同程度的破坏,这次地震还使建筑质量问题暴露无遗,同时介绍了土耳其的地震构造及历史地震记录以及土耳其的地震机构,立法和国际合作与研究工作情况。     

华北地区地震活动主体地区的迁移

本文分析了华北地区第三地震活动期和第四地震活动期内各地震幕地震活动的主体地区,发现在一个地震活动期内各地震幕的地震活动主体地区有自西向东然后又自东向西迁移的现象。文章最后讨论了华北地区未来地震活动幕可能的主体地区。     

日本内陆地震活动的迁移与扩散

本文研究了日本内陆及其外围海域发生大地震后的地震活动迁移现象。在所研究的6个震例中,一个共同的特点是,地震活动的迁移总是沿着地壳内的活动地质构造带发生。有时可以根据地震活动的迁移来进一步确定活动构造带的存在。把板块边缘地区的地震活动类比为沿着力学偶合平面迁移和扩散,我们可以认为,岛上的活动构造带对应着地壳块体的力学相互作用边界。地震迁移的形式可能不只一种。在我们所研究的震例中发现了以下特征:地震迁移速度约为几km/年;大地震震源区之间存在着地震空区;在每一条地震带上有一定的地震活动周期。地震迁移的一种可能机制是:由于地壳块体的相对运动,在其边界上的凹凸不平区造成了构造应力集中,这些凹凸不平区相继地发生破裂,形成了地震迁移。     

大地震发生的长期预测

前言1 995年的阪神淡路大震灾 ,使日本的地震调查研究受到了巨大的打击。从国家政策方面讲 ,已根据地震防灾对策特别措施法在总理府设置了地震调查研究推进总部 ,并于 1 999年 4月起草了关于推进有关地震的观测、测量、调查和研究的综合性的基本方案。方案中列举了目前应推进的 4个地震调查研究课题。第 1个课题就是“调查活断层 ,对地震发生的可能性作长期评估 ,绘制包括强地面运动预测等内容的地震动预测图。”目标很明确 ,就是要在对地震的发生作出长期预测的基础上 ,对将来可能发生的强地面运动作出预测 ,以便在地震对策方面发挥作用。…     

中国大陆东部地区地震活动图像及其含义

定量处理了中国大陆东部地区2000～2002年的中小地震活动图像,分析了地震活动密集值的相对变化及其含义,探讨了其在中期地震预测中的应用。     

1936年广西灵山6(3/4)级地震极震区震害和地震影响场的研究

１９３６年广西灵山６级地震是南海北缘内陆最强的一次地震，也是震害最严重的一次，震中烈度９度强。倒房率震害指数甚高，地面破坏和其它宏观现象也非常突出，形成两个极震区，其一长轴北东东向，其二长轴北北西向。这些震害和影响场特征以及地面破坏等宏观现象均可用本区地质、地貌环境得到合理解释。     

新疆特克斯-昭苏地震断层的发现及有关问题的讨论

1986年作者在特克斯-昭苏盆地首次发现长70公里、最大垂直和水平位移均达8米的地震断裂带和地震形变现象,并认为是1716年地震时形成的。地震断裂带的展布和运动方式,与科博河-昭管处断裂相一致。特克斯断裂带是一条复杂的断裂带,它由多条断裂组成。1716年地震表明该断裂带具有新的活动性     

研究地震和岩石破裂现象的非线性科学方法

本文以地震孕育和岩石破裂过程的阶段(包括裂纹系形成、变形局部化和断层形成、断层活动和松弛)为线索,阐述了非线性科学方法(包括分形几何学,自组织临界现象和混沌动力学)的应用,提出了地震孕育过程和岩石破裂各阶段的普适性特征、机理和要着重研究的课题.     

地震预测的物理基础与可能性

地震不是随机发生的，在地震发生之前，震源区存在介质弹性减弱，密度减小，体积膨胀的孕震过程，它将引起各种地球物理方法的前兆观测手段出现形形色色的变化，只要坚持实践－研究－再实践，反复不断地加深规律认识，不断地积累探索，就能循着渐进式预测之路，逐渐实现地震预测。     

青海共和地震异常现象分析

通过回忆共和地震前出现的反常现象,认为地震发生前有预兆,并通过这些预兆使人们提高警惕,做好地震预报、地震应急的准备工作。     

数字地球与综合防震减灾

地震是破坏力巨大的灾害性自然现象。本世纪以来全国因地震灾害造成百余万人伤亡和数千亿美元的经济损失。综合防震减灾包括4方面工作。作以建立综合防震减灾技术系统为例。阐明了数字地球概念在自然灾害预测预防中的应用前景。     

Mechanisms of seismic quiescences

In the past decade there have been major advances in understanding the seismic cycle in terms of the recognition of characteristic patterns of seismicity over the entire tectonic loading cycle. The most distinctive types of patterns are seismic quiescences, of which three types can be recognized:post-seismic quiescence, which occurs in the region of the rupture zone of an earthquake and persists for a substantial fraction of the recurrence time following the earthquake,intermediate-term quiescences, which appear over a similar region and persist for several years prior to large plate-rupturing earthquakes, andshort-term quiescences, which are pronounced lulls in premonitory swarms that occur in the hypocentral region hours or days before an earthquake. Although the frequency with which intermediate-term and short-term quiescences precede earthquakes is not known, and the statistical significance of some of the former has been challenged, there is a need, if this phenomena is to be considered a possibly real precursor, to consider physical mechanisms that may be responsible for them.The characteristic features of these quiescences are reviewed, and possible mechanisms for their cause are discussed. Post-seismic quiescence can be readily explained by any simple model of the tectonic loading cycle as due to the regional effect of the stress-drop of the previous principal earthquake. The other types of quiescence require significant modification to any such simple model. Of the possibilities considered, only two seem viable in predicting the observed phenomena, dilatancy hardening and slip weakening. Intermediate-term quiescences typically occur over a region equal to or several times the size of the rupture zone of the later earthquake and exhibit a relationship between the quiescence duration and size of the earthquake: they thus involve regional hardening or stress relaxation and agree with the predictions of the dilatancy-diffusion theory. Short-term quiescences, on the other hand, are more likely explained by fault zone dilatancy hardening and/or slip weakening within a small nucleation zone. Because seismicity is a locally relaxing process, seismicity should follow a behaviour known in rock mechanics as the Kaiser effect, in which only a very slight increase in strength, due to dilatancy hardening or decrease in stress due to slip weakening, is required to cause quiescence. This is in contrast to other precursory phenomena predicted by dilatancy, which require large dilatant strains and complete dilatancy hardening.Lamont-Doherty Geological Observatory     

日本兵库县南部地震调查与中国唐山大地震的比较

叙述了１９９５年１月日本兵库县南部地震的强地面运动特征，并与１９７６年中国唐山地震的地面运动特征进行了对比，讨论了日本地震后次生灾害——火灾的残酷性，并分析了该次地震的前兆现象     

地震迁移现象研究综述

地震迁移活动是地震活动的一种普遍现象。经过对研究该现象的文献学习整理,发现前人的研究重点可分为三类：第一类侧重于对迁移现象的描述,迁移规律具有局域性;第二类侧重于对迁移规律形成机理的探讨,基本都归因于板块的相互作用和岩石圈下部软物质的运动;第三类侧重于在迁移现象分析的基础上进行地震预测、预报的实践。     

An earthquake instability model based on faults containing high fluid-pressure compartments

It has been proposed that large strike-slip faults such as the San Andreas contain water in seal-bounded compartments. Arguments based on heat flow and stress orientation suggest that in most of the compartments, the water pressure is so high that the average shear strength of the fault is less than 20 MPa. We propose a variation of this basic model in which most of the shear stress on the fault is supported by a small number of compartments where the pore pressure is relatively low. As a result, the fault gouge in these compartments is compacted and lithified and has a high undisturbed strength. When one of these locked regions fails, the system made up of the neighboring high and low pressure compartments can become unstable. Material in the high fluid pressure compartments is initially underconsolidated since the low effective confining pressure has retarded compaction. As these compartments are deformed, fluid pressure remains nearly unchanged so that they offer little resistance to shear. The low pore pressure compartments, however, are overconsolidated and dilate as they are sheared. Decompression of the pore fluid in these compartments lowers fluid pressure, increasing effective normal stress and shear strength. While this effect tends to stabilize the fault, it can be shown that this dilatancy hardening can be more than offset by displacement weakening of the fault (i.e., the drop from peak to residual strength). If the surrounding rock mass is sufficiently compliant to produce an instability, slip will propagate along the fault until the shear fracture runs into a low-stress region. Frictional heating and the accompanying increase in fluid pressure that are suggested to occur during shearing of the fault zone will act as additional destabilizers. However, significant heating occurs only after a finite amount of slip and therefore is more likely to contribute to the energetics of rupture propagation than to the initiation of the instability.We present results of a one-dimensional dynamic Burridge-Knopoff-type model to demonstrate various aspects of the fluid-assisted fault instability described above. In the numerical model, the fault is represented by a series of blocks and springs, with fault rheology expressed by static and dynamic friction. In addition, the fault surface of each block has associated with it pore pressure, porosity and permeability. All of these variables are allowed to evolve with time, resulting in a wide range of phenomena related to fluid diffusion, dilatancy, compaction and heating. These phenomena include creep events, diffusion-controlled precursors, triggered earthquakes, foreshocks, aftershocks, and multiple earthquakes. While the simulations have limitations inherent to 1-D fault models, they demonstrate that the fluid compartment model can, in principle, provide the rich assortment of phenomena that have been associated with earthquakes.