花岗岩变形破坏的阶段性模型--应力速度及预存微裂纹密度对断层形成过程的影响

依据对具有较高微裂纹密度的筑波花岗岩和极低微裂纹密度的花岗斑岩 2种极端的岩石标本、在等应力速率的快速加载 (约 6MPa/min)和蠕变加载 (轴向应力保持在约 95 %破坏强度 ) 2个极端的加载条件下的实验结果 ,讨论了预存微裂纹密度与加载速度对多晶质结晶岩变形破坏过程的影响。实验中利用高速多通道声发射波形数字记录系统 (每秒可记录多达 5 0 0 0个声发射事件的 32通道波形 ) ,获得了岩石标本破坏前微破裂活动的详细时空分布数据。声发射的发生率、震级 -频度关系中的b值及震源的空间分布揭示出岩石变形破坏过程中微破裂活动具有 3个典型阶段 :初期阶段、第 2阶段和成核阶段。尤其是在成核阶段 ,还观测到发生率和b值有大幅度前兆性起伏。一般而言 ,在相同加载条件下预存微破裂密度越高 ,或对同一岩石加载速度越慢 ,对应的断层成核过程就越长 ,因此最终破坏的可预报性也越高。为了进一步探讨微破裂活动的阶段性特征及其物理本质 ,还利用亚临界破裂扩展模型对声发射数据进行了理论分析     

NOTE ON THE GEOMORPHOLOGY OF THE NORTH SHENSI BASIN

The geology of the north Shensi basin has been studied to some detail bythe American geologists Fuller,Clapp and others~1 in an oil exploration partysent out in 1914 under the joint auspices of the Chinese National Oil Administra-     

双轴压力下岩样自电位变化实验的新结果

利用伺服控制双轴加载系统,采用阵列式布局的应变、自电位测量方法,对岩石样品弹性变形阶段和破坏过程中的应变和自电位进行了实验研究. 结果表明,在突然加卸载、黏滑和岩样破裂几种特定情况下,自电位和应变场均出现了互相关联的脉冲状突然变化,且具有相当大的空间展布. 尽管有时应力σ值相当高,但当应力变化率γ= dσ/ dt为零（恒载）且保持正、负常数（匀速加、卸载）时,自电位始终没有异常出现. 反之,无论γ的增量Δγ为正值或负值,当γ突变,即对样品进行突然加卸载的时刻则出现了脉冲状自电位信号ΔV,Δγ的正或负对ΔV的影响是相反的. 分析表明,应力突变时ΔV与Δγ的异常幅度成正比. 应力突变和岩石破裂过程中自电位明显的时空变化意味着,孕震区附近如果自电位有突变,就有可能观测到相关的自电位前兆和同震变化, 并可能出现同步的应变变化,这给地震的自电位和应变前兆方法提供了实验证据.     

Uraniferous Black Shale and Related Uranium Mineralization Features in South China

: Black shales are marine sediments with argillaceous, silty and siliceous compositions and high contents of organic materials, disseminated pyrite and uranium. Uraniferous black shale has uranium content of more than 20 ppm.Black shales are widely distributed in 17 provinces or autonomous regions in northwestern and southern-central China. Their sedimentary ages are from the Sinian to the Tertiary and uraniferous black shales are mainly exposed in Yunnan, Guizhou, Sichuan, Hunan, Hubei, Jiangxi, and Zhejiang provinces and Guangxi Zhuang Autonomous Region and the economically significant uranium deposits associated with black shale occur in Hunan and Jiangxi provinces and Guangxi Zhuang Autonomous Region.Uranium mineralization associated with black shale has the following main features: (1) forming stratabound deposits; (2) controlled by structures such as interlayer and intersected faults and fractures; (3) associated with different ore-forming processes such as leaching and hydrothermal reworking; (4)     

88小时:美国地质调查局国家地震信息中心对2011年3月11日Mw9.0日本地震的响应

引言 2011年3月11日日本本州岛东海岸附近海域发生的M9．0地震（Tohoku earthquake,以下称“东日本大地震”——译者注）及其引发的海啸造成数以万计的人员死亡,造成的财产损失可能超过1万亿美元,这是有历史记录以来最严重的自然灾害之一。     

各向异性ATI介质剪切位错点源P波远场辐射

假设震源区为ATI介质,传播介质为全空间各向同性介质情况下,给出了剪切位错源P波远场辐射解析表达式,讨论了震源区各向异性对远场P波振幅和震源球的影响。结果表明,震源区裂隙密度,裂隙方位等参数的动态变化导致P波远场辐射花样也随之动态变化,同时也会造成非双力偶百分含量的动态变化。研究认为,在井中对中小地震的非双力偶机制进行...     

1949年新疆库车7.4/级地震的地震构造条件

前人研究认为 ,库车 194 9年 7 级地震主要与天山南麓活动构造带的NEE向秋立塔格断裂有关。最近笔者根据深地震地壳测深、石油地质及活断裂等研究的新成果 ,对这次地震的构造条件进行了较深入的分析。塔里木陆块向天山俯冲 ,天山上地壳被挤压块断隆升并侧向推覆扩展 ,于天山南缘形成库车盆地及由秋立塔格等一系列逆断裂组成的逆断 -褶皱系 ,这是发育于沉积盖层的薄皮构造。NE向库车 -依西 1井断裂是库车盆地构造中重要的传递断裂 ,位于NE向的乌鲁木齐 -库车 -柯坪构造带中。有关 7 级地震的地震学研究结果与秋立塔格断裂完全不符 ,而与库车 -依西 1井断裂基本一致     

InSAR地形测绘若干问题研究

目前,我国已经把InSAR技术作为完成西部测图任务的重要技术手段之一,为了解决影响InSAR应用的技术瓶颈问题,促进InSAR技术的实用化,把InSAR技术应用于实际测绘生产之中,本文对InSAR相位解缠、干涉参数定标、解缠相位到高程转换、InSAR测绘作业流程及SAR影像制图等技术进行了研究;为了促进InSAR技术的进一步发展,为下一代InSAR系统的研制和应用奠定基础,本文对SAR图像仿真技术和干涉图仿真技术进行了研究,并在仿真数据的基础上,对多基线/多波段InSAR相位解缠技术进行了研究。本文在InSAR测绘作业流程设计、区域网平差干涉参数定标与高程控制点加密、SAR影像制图综合等方面的研究成果,对于促进我国InSAR技术的实用化和工程化具有积极意义;在SAR图像仿真和干涉图仿真方面的研究,为SAR系统设计和SAR仿真的应用奠定了基础;在多基线、多波段InSAR相位解缠方面所取得的研究成果,将促进我国多基线、多波段InSAR技术的发展。     

THE DECADAL CLIMATE VARIABILITY AND THE ANOMALOUS ENSO DEVELOPMENTS IN 1990S

By using the wavelet transform method,the ENSO(2—7 a)signal and the decadal variability(8—20 a)are filtered out from the long-term SST data sets in order to investigate characteristicsof the decadal variability and its impact on the ENSO.It is found that there are two different kindsof decadal SSTA modes-horseshoe and horse saddle patterns in the tropical Pacific.Thehorseshoe pattern represents that the decadal SSTA variability in the central Pacific is in phasewith that in the eastern Pacific.The horse saddle pattern is named that they are out of phase.Theformer constituted the decadal variability before 1990s and the latter mainly prevailed during1990s.As the response of atmosphere to the ocean,two decadal wind patterns appear inassociation with the SST decadal modes.One is characterized by anomalous development of thezonal wind,the other by anomalous development of the meridional wind.These two kinds ofmodes can also be regarded as different phases of the decadal oscillation.Further studies haveshown that the influences of the two kinds of modes on the ENSO are different.The horse saddlemode has a stronger impact on the ENSO than the horseshoe mode.A possible mechanism for the influence of the decadal variability on the ENSO signal ispresented.The central part of the thermocline along the equatorial Pacific moves up or downsimultaneously with its eastern part while the decadal variability bears the horseshoe pattern.Butthe two segments of the thermocline in the central and eastern Pacific act oppositely while thedecadal variability shows the horse saddle pattern.In this case it has an-influence on the individualENSO'events by the superposition of the decadal variability.     

Parallelization Load Balance Strategy for a Global Grid-Point Model

The Global/Regional Assimilation and PrEdiction System (GRAPES) is a new-generation operational numerical weather prediction (NWP) model developed by the China Meteorological Administration (CMA).It is a grid-point model with a code structure different from that of spectral models used in other operational NWP centers such as the European Centre for Medium-Range Weather Forecasts (ECMWF),National Centers for Environmental Prediction (NCEP),and Japan Meteorological Agency (JMA),especially in the context of p...