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。     

四川省沐川5级地震和盆地南缘地震趋势的分析

本文介绍了淮阴１号桥钢筋混凝土组合梁桥面系的施工工艺，钢梁及斜索的安装，桥面混凝土裂缝控制等方面的问题。     

新沂-泗县地震危险区地震活动和地震构造

运用深浅部构造对比研究、构造解析技术，结合历史地震资料、中强震观测资料分析、地震活动性分析结果，探讨中强震过渡区地震构造环境和地震韵律的研究途径，圈定出新沂—泗县地震危险区。对该危险区进行立体综合剖析，推演出未来中强震发生的空间部位，并预测了该区未来可能发生地震的震源深度、震级、地震长轴衰减方向、地震复发间隔等参数。     

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。     

1994年1—3月的全球地震动态

1994年第一季度，全球地震活动仍为中等水平，三个月内共发生三次7级以上浅源地震。秘鲁－玻利维亚边界发生大深震。美国加州又发生强烈地震。大洋岛弧地震带本季度地震活跃。伊朗发生三次6级地震。     

瓦屋山水电站水库诱发地震危险性研究

瓦屋山水电站位于川南台陷南端，南邻峨眉山断块，水库南缘的毛沟断裂最新活动时期为晚更新世，水库处于活动性大地构造环境中，该区属于名山－马边－昭通过地震北段，以弱震活动为主，伴有少量中强地震，目前正处于地震活动期，从分析库区地质构造，水文地质，工程地质，地震活动等条件，并使用水库综合影响系数法，贝叶斯概率预测法，断层强度分析法，判定库区存在着发生构造型水库诱发地震的可能性，诱发地震强度Ｍｓ≤５．５。划     

Tracing the Forecast of Earthquakes Based on the Seismicity Characteristics of the Chi-Chi Strong Earthquake Swarm Sequence

The data of earthquakes with M≥3.0 during the 7 years from September 21, 1993 to September 20, 2000 recorded by the Taiwan Central Weather Bureau (CWB) show that there were 6 types of clear characteristics of seismicity during the Chi-Chi strong earthquake swarm of September 21. These 6 types of characteristics are (1) foreshock types, (2) seismic gaps, (3) seismic bands, (4) clustering activity of foreshocks and signal shock, (5) quiescence before the main shock and (6) secondary aftershocks in the aftershock sequence. Using the procedures for analyzing the yearly strong earthquake tendency, further tracing based on the earthquake sequence characteristics, and taking the Chi-Chi earthquake sequence as an example, tracing analysis of the earthquake tendency was attempted using the shorter time range of monthly rather than in a yearly time scale. An attempt was made to establish the procedures for tracing analysis of shallow-focus earthquakes in the seismic belt of western Taiwan. It is hoped that this can provide an analystical method for approaching the short-imminent time scale of seismometry-based earthquake forecasting.     

地震电磁辐射研究的新进展

本文简要评述了近年来震前电磁辐射研究的新进展和发展方向,以及今后的重点研究课题.已取得的初步结果表明,新发现的震前电磁辐射现象是一种客观存在,并可能是具有良好应用前景的短临前兆.鉴于地震电磁辐射机制及其空间耦合与时间变化过程的复杂性,必须深入探索电磁辐射前兆现象与孕震过程之间的内在联系,使观测工作与理论研究很好地结合起来,并结合多种前兆进行综合诊断.      

Experimental study on the mechanism of non-synchronism of seismo-electromagnetic radiation precursors

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Experimental study of the features of VLF, MF, HF and VHF electromagnetic radiation accompanying rock fracture

In order to investigate the physical mechanism of seismo-electromagnetic signals, many scholars from China and other countries have carried out laboratory and field experiments of rock samples by loading them up to fracture in recent ten-odd years. In each of these experiments, the phenomenon of electromagnetic radiation was observed during the process of rock sample fracture. However, the experimental results can not explain the non-synchronous electromagnetic radiation in actual observation records. In these records, some stations displayed anomalies but some others did not, and the signals of different frequency bands observed by the same station did not occur simultaneously. This has brought about many difficulties to the application of electromagnetic radiation in earthquake prediction. The experimental result of this paper can explain the phenomenon of non-synchronous electromagnetic radiation. In the experiment of this paper, rock samples are uniaxially compressed up to fracture. The antennas of different frequency bands are installed two meters away from the rock sample in different directions. The electromagnetic signals during the whole process of rock sample fracture are recorded synchronously by a 14-channel tape recorder. The experimental results are as follows: (1) signals of the four frequency bands: VLF, MF, HF and VHF, are all recorded during the main fracturing process of rock samples, but signals of different frequencies may somtimes occur non-synchronously; (2) the intensity of electromagnetic radiation is the highest at the moment when the main fracture occurs, but signals in different directions are of different intensities. The above results are consistent with the non-synchronous electromagnetic radiation observed in real earthquakes. It seems possible to predict the orientation of future seismic source by the electromagnetic method of the LF or VLF frequency bands. Contribution No. 95A0075, Institute of Geophysics, SSB, China. The paper is translated by Prof.Jie-Fan HUANG, Peking University from the Chinese into English version.     

地中电偶极源极低频电磁场的分布与传播特征

利用层状大地中偶极源响应的正演算法, 计算地中电偶极源激发的极低频地震电磁场并分析其在地球环境下的传播特征.设计了多个水平层状地球模型, 分别模拟和展示了深埋地中的电偶极源的响应和空间分布特征.重点分析了含地壳波导+LAI波导模型的高阻大地中, 倾斜电偶极源激励响应随观测点的偏移距和垂直位置、激励源深度、地壳波导结构和参数变化时各场量响应的幅频特征.研究表明, 用倾斜电偶极源模拟和分析高阻大地中孕震电磁辐射的响应及在大地电磁系统中的传播特性是可行的; 模拟的高阻大地中的电磁辐射在地壳波导和LAI波导中均表现有慢衰减或幅值增强特性, 但两个波导效应具有不同的频率选择性; 高阻大地中的电磁辐射在波导的高阻介质中具有幅值强、衰减慢的特点.建议在高阻地层出露的地表、井中或海底的高阻岩层中以及大气层中布设测站.

     

日本9.0级大地震前长波辐射异常研究

应用聚类分析方法对日本Mw9.0地震前长波辐射进行了分析,结果表明2010年8月在大范围的西太平洋海域,出现一个自北向南逐渐增强的季节性高温条带,该条带从日本海沟中北段开始,一直向南延伸到伊豆—小笠原海沟.同时日本海沟的地壳垂直运动自2010年8月份开始出现季节性运动消失的异常现象.这两种现象同时出现是否表明地球物理场在大地震发生前可能出现异常？地震发生前半年时间出现的热异常条带是否与此次地震有关？这些问题有待进一步探索.     

日本9.0级大地震前长波辐射异常研究

应用聚类分析方法对日本M_w9.0地震前长波辐射进行了分析,结果表明2010年8月在大范围的西太平洋海域,出现一个自北向南逐渐增强的季节性高温条带,该条带从日本海沟中北段开始,一直向南延伸到伊豆—小笠原海沟.同时日本海沟的地壳垂直运动自2010年8月份开始出现季节性运动消失的异常现象.这两种现象同时出现是否表明地球物理场在大地震发生前可能出现异常？地震发生前半年时间出现的热异常条带是否与此次地震有关？这些问题有待进一步探索.     

1994年10月22日辽宁朝阳西北Ms4.6级地震的短期预报：预报纪实之二

根据１９９４年４月以后国内外大小地震的活动情况对１０月９日内蒙Ｍｓ４．０级和２２日朝阳西北Ｍｓ４．６级地震试做了符合实际的短期预报。文末对这次预报及对域外大形势活动背景进行了简单的讨论。     

地震电磁前兆的观测

地震的电磁前兆现象越来越受到人们的关注,地震电磁观测技术也在不断地得到发展和改进,已经由被动的观测发展到主动的观测,由地面局部的观测扩展到空间卫星全球范围的观测。文中介绍当前国内外在地震电磁观测方面的研究进展和实例,展望了我国未来地震电磁观测技术的发展。     

WINTER RADIATION EXTINCTION AND REFLECTION IN A BOREAL PINE CANOPY: MEASUREMENTS AND MODELLING

Predicting the rate of snowmelt and intercepted snow sublimation in boreal forests requires an understanding of the effects of snow-covered conifers on the exchange of radiant energy. This study examined the amount of intercepted snow on a jack pine canopy in the boreal forest of central Saskatchewan and the shortwave and net radiation exchange with this canopy, to determine the effect of intercepted snow and canopy structure on shortwave radiation reflection and extinction and net radiation attenuation in a boreal forest. The study focused on clear sky conditions, which are common during winter in the continental boreal forest. Intercepted snow was found to have no influence on the clear-sky albedo of the canopy, the extinction of short wave radiation by the canopy or ratio of net radiation at the canopy top to that at the surface snow cover. Because of the low albedo of the snow-covered canopy, net radiation at the canopy top remains positive and a large potential source of energy for sublimation. The canopy albedo declines somewhat as the extinction efficiency of the underlying canopy increases. The extinction efficiency of short wave radiation in the canopy depends on solar angle because of the approximately horizontal orientation of pine branches. For low solar angles above the horizon, the extinction efficiency is quite low and short wave transmissivity through the canopy is relatively high. As the solar angle increases, extinction increases up to angles of about 50°, and then declines. Extinction of short wave radiation in the canopy strongly influences the attenuation of net radiation by the canopy. Short wave radiation that is extinguished by branches is radiated as long wave, partly downwards to the snow cover. The ratio of net radiation at the canopy top to that at the snow cover surface increases with the extinction of short wave radiation and is negative for low extinction efficiencies. For the pine canopy examined, the daily mean net radiation at the snow cover surface became positive when daily mean solar angles exceeded 22° in late March. Hence, canopy structure and solar angle control the net radiation at the snow cover surface during clear sky conditions and will govern the timing and rate of snowmelt. Models of intercepted snow sublimation and forest snowmelt could beneficially incorporate the canopy radiation balance, which can be extrapolated to stands of various canopy densities, coverage and heights in a physically based manner. Such models could hence avoid ‘empirical’ temperature index measures that cannot be extrapolated with confidence.     

2008年10月5日新疆乌恰6．8级地震发震构造与地震序列分析

2008年10月5日新疆乌恰县发生MS6．8地震,这是继2008年3月21日新疆于田7．4级地震后新疆发生的又一次强震。从地震基本参数、发震构造、震源机制解、地震序列、震中分布等方面对这次地震进行了初步分析。