大规模宏观异常的双重性及其在地震预报中的意义

宏观异常的大规模出现是地壳强烈活动的重要标志 ,常与其后的强震活动相关。中国多次强震短临预测的成功 ,在一定程度上依赖于大规模的宏观异常。然而 ,宏观异常也具有二重性 ,一方面可作为重要的地震短临前兆 ,另一方面也可能是由构造活动引起的 ,不具有前兆的性质。因此 ,在地震预报的科学探索中 ,应大力加强宏观异常的观察、观测、分析与研究 ,识别地震前兆与构造活动异常的区别 ,使宏观异常在地震预报中发挥积极的作用     

动物习性异常作为地震前兆研究的历史与未来

地震前动物习性异常在很早就有历史文献记录记载。动物习性异常是海城地震预报中重要的宏观前兆之一。此后动物习性异常作为地震前兆的研究在全世界范围内得到重视。因为地震并不是动物习性异常的唯一原因,这一研究后来基本上被放弃。在生命科学的研究达到分子水平并进入基因层次以后,动物习性异常作为地震前兆的研究又重新开始。现在的研究试图从基因遗传水平上解释动物的地震避险能力是如何遗传与进化的,并运用现代分子生物学的技术解开动物习性异常的机理,找出作为地震前兆的特有反应,从而做出地震预报。     

对地震前兆异常的一些再思考

通过研究地震远场前兆异常、超长期(8~20a)前兆异常和前兆异常判别上的差异,进一步揭示远场前兆异常的意义、前兆异常曲线的内涵和地震间的相互关联及地震预报的复杂性。该研究有助于进一步了解前兆异常的实质和深化地震预报。     

前兆异常的识别

前兆异常对于地震预报具有非常重要的意义,在实际工作中,怎样来识别地震前兆异常,也就是怎样从各种观测手段所得到的千变万化的曲线形态中,客观地提取地震前兆异常作为我们地震预报的可靠根据,是一个非常重要的问题。一、问题的提出在实际观测中,我们常常遇到类似于     

强震远场前兆异常在地震预报中的应用

强震不仅有近场前兆异常，而且也有远场前兆异常，后者在地震预报中可以起到三个方面的作用：（１）远场前兆异常多在震前的短临阶段准同步地出现，为短临预报提供了较丰富的信息，有助于作出短临预报；（２）远场前兆异常一般具有双重或多重前兆的性质，它们是比较可靠的前兆异常，可为预报地震提供依据；（３）远场前兆异常显示明显的地区，是应力积累较高的地区，往往是后继地震发生地方，即指出了地震可能发生的地域。因此，对远     

地震前兆研究中的一些疑点

由于缺乏对地震孕育和发生机理的认识，地震前兆异常判别受到人们的认识水平、周围环境甚至心理因素的影响，带有很大的随意性，以致在地震预报中出现诸多的怪异现象：地震前兆多是事后总结出来的；绝大多数异常之后没有地震发生；多数地震之前测不到前兆异常；前兆测值对近处地震无反应，但其异常与远处地震对应较好；前兆异常缺乏重现性；异常数量与台站多寡、震情紧张程度密切相关，等等。这些都说明，在地震科学的研究中，我们仍应从最基础的工作做起，再逐步地实现地震预报。     

地震群测群防好

我国地震又进入了新的活跃期,几亿人在担心如果明天有大地震能预报吗?当前世界各国地震专家认为地震预报比癌症更难对付。1975年海城地震的成功预报避免了10万人死亡,减少40亿元的经济损失。海城大震前除微观异常以外还获得了大量的宏观前兆,广大群众发现和报告这些宏观异常现象是成功预报的重要内容。而唐山大震前也有明显的动物、井水等宏观前兆,但没能作出预报,为此我们应该汲取几十万人殉难的惨痛教训。     

地震前兆异常证据可信度

就确定地震前兆异常证据可信度的原则、思路和计算方法进行了研究, 并举例说明。目的是根据各学科地震分析预报方法指南的内容, 采用较统一的确定方法来获得22项地震前兆异常(空区、条带、b值、C值、波速比、地震活动异常增强、地震活动异常平静、地震窗、震群、地震序列、尾波、P波初动、应力降、地电、地磁、地应力、地倾斜、水物理、水氧和水化、重力、空间环境、宏观异常)的异常证据可信度, 配合地震预报专家系统的推广应用。      

地壳形变与地震前兆探索回顾和展望

本文回顾了我国地震预报中地壳形变观测技术、 数据处理方法和软件及地壳形变前兆观测研究进展。 1966年邢台地震后, 我国地震预报工作经历了难得的成功、 更多惨痛失败和“地震不可预报论”等干扰, 发展曲折。 尽管2008年汶川和2011年东日本大地震预报失败,但这两次和其他大地震前后GPS和其他观测得到的地壳形变表明, 大地震是有前兆的, 是可以预报的。 比较了我国地震预报所采用的主要的地形变观测技术和分析方法, 讨论了观测和数据处理方法的特点, 简要介绍了地壳形变地震前兆新近的研究结果, 重点阐述了GPS观测技术多方面的优势。 事实证明, GPS观测得到的汶川大地震前的形变异常或前兆, 是我国地壳形变观测与地震前兆探索最突出的成果。     

关于地震预报科学思路,方法论及难点的思考

中国地震预报的科学思路为整体观指导下的异常群体阶段性追踪预报模式。在方法论方面强调了宏观唯象方法的重要性,认为利用地震学、地球物理、地壳形变和地球化学等资料,采用统计识别的方法来寻找地震前兆、进行三要素预报是解决孕震过程这类复杂系统的较好方法。同时指出,地震成因、震源孕育物理力学过程、前兆成因机制、临震阶段起主宰作用的变量等是地震预报的难关所在。临震阶段潮汐力、气压、降水等这些平时视为干扰因素的变化,可能成为发震的触发调制因素。从而增加了前兆的复杂性,在排除干扰时应特别注意。     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases     

Solute concentrations in the lower niger river and the source rock contribution

Water quality analyses for the Niger River for the 1980/81 hydrological year are presented. The samples were collected from the main river at Lokoja, and from two main tributaries, the Kaduna and the Benue Rivers. Different water types were distinguished by the concentrations of major ions. The type Ca > Na > Mg > K - HCO₃ > SO₄ > Cl was represented at all stations during at least part of the year. Chloride was found to dominate the sulphate ion in the Kaduna and Niger, while the Benue maintained a higher concentration of sulphate relative to chloride all year round. Distinct patterns of seasonal variation in the ion concentrations were observed, particularly for the samples collected at Lokoja. Low ion concentrations were prominent during periods of high discharge, while low flow periods coincided with high dissolved ion concentrations. The contribution of rainwater to the total dissolved solids in the river waters was assessed indirectly using rainwater chemistry data from the Gulf of Guinea. The estimated rainwater contribution to the Lower Niger amounts to 5.15 mg 1^?1. Geochemical weathering calculations involving reactions of the four major minerals of granitic rocks - anorthite, biotite, albite, and K-feldspar - with carbon dioxide and water, can account for the average water composition of the Lower Niger. The proportion of the ionic components was also related to the occurrence of the respective element in the minerals.