应力减小引起的岩石破坏与地震

最近完成的岩石力学三轴实验表明,岩石的破坏既能由最大主应力的增加引起,又能由中等主应力的变化(增加或减小)或最小主应力的减小引起,因此联系到地震的发生也是如此。地震前必须有一个应力和能量的增加过程,但地震不一定发生在应力和能量的增加过程中,地震也可以发生在应力和能量的减小过程中。文章还讨论了能够引起地壳中应力减小的作用,並从地震活动性方面探索应力减小引起地震的可能性。     

岩石摩擦滑动的声发射b值

用双剪法进行岩石摩擦实验并测定了声发射b值。实验表明,粘滑发生前b值稳定并稍有增加,多次粘滑过程中b值基本不变,随着正应力的增加b值增加。     

关于发震断层与静止断层交遇的讨论

发震断层在其传播过程中与静止断层的交遇是地震时带有普遍性的现象,本文把交遇问题分为四种基本类型;建立各自相应的力学模型;通过物理力学分析和数学模拟,并结合地震实例讨论了各类交遇可能产生的后果: 1.发震断层终止于交遇处。2.发震断层被静止断层所截,而后,交遇区域发生强余震。3.发震断层穿越静止断层向前传播,而后,可能发生共轭地震。这些讨论可能对预测未来大震的震级及强余震的发生有一定的意义。     

A Computer Model for Cyclic Activity of Strong Earthquakes in Continental Seismic Zones

Based on the study of activity of earthquakes with M**********>7.0 in mainland China,we have found a dynamic pattern,i.e.,the cyclic characteristics in time and migration from one seismic zone to another in space.In order to understand the physical mechanism of this pattern,we use a nonlinear dynamic model to simulate the seismic activity in fault zones under a unified tectonic stress field.The basic elements in our model consist of a Maxwell body and a rigid sliding block.Basic elements in a column represent a fault,and coupling elements connecting different columns simulate the interaction among faults and fault segments.The results provide insights to the cyclic activity of strong earthquakes and to the feature of mutual influence between strong earthquakes in groups in the climax of seismic activity.     

Theory and Experimental Results about the Application of Remote Sensing to Earthquake Prediction

In this paper,the theory for applying remote sensing to earthquake prediction has been elucidated and an experiment has been made.Through the experiment,it has been found that the characteristics and temperature of infrared radiant of rocks vary as a function of rock stress,the order of magnitude of radiance variation is 10-5(W/cm2 sr um),the amount of variation of the radiant temperature is 0.2℃~0.8℃ and some significant precursor information has been discovered.The experiment has verified preliminarily that the advanced technology of remote sensing can be applied to earthquake prediction.     

不同应力途径下岩石的体积变化

本文介绍了对岩石在不同应力途径下的体积变化进行的实验研究。主要的应力途径有三种,并且都是首先把岩石加载到破裂前一定的应力状态,再分别三种类型加载。实验用电阻应变片测量纵向和横向应变以计算体应变。实验表明:同一种岩石在不同应力途径下膨胀效应有显著的不同。文中用辉长岩的实验数据对过密量和超膨胀量进行了估算。研究表明,过密与膨胀是应力途径变化时岩石体积变化的滞后效应。研究了B型实验过密状态出现的条件。从强度80%左右开始减小最小主应力的B型实验明显表现经历过密状态。从低应力状态(强度50%左右)和高应力状态(强度92%以上)开始减小最小应力的B型实验,岩石均未经历过密状态。最后联系地震预报问题进行了简单的讨论     

西藏日喀则群昂仁组时代问题新资料

昂仁组是一套复理石和类复理石沉积,含晚白垩世土伦期的菊石Mammites^[1,2],但因未发现直接的上覆地层和化石稀少而不能肯定是否还包括晚于土伦期或至早第三纪的沉积^[1,3]。1980年,笔者在昂仁、萨噶一带的昂仁组中采到瓣鳃、腹足化石;我局区调队在仲巴县错江顶一带,发现连续沉积于昂仁组之上,整合于下第三系之下一套含Masstrichtian期菊石(Sphenodiscus)的杂色地层。本文报道这一发现和对昂仁组时代问题的认识(图1)。     

Methods and applications of 3-D wave equation common-azimuth prestack migration

To tackle the difficulties of a 3-D full volume prestack migration based on the double-square-root (DSR) one-way wave equation in practical applications, the common-azimuth migration approach is first discussed using dual-domain wave propagators under the theoretical frame of crossline common-offset migration. Through coordinate transforming, a common-azimuth prestack tau migration technology that recursively continues the source and receiver wavefields and picks up the migrated results in the two-way vertical traveltime (tau) direction is developed. The migrations of synthetic data sets of SEG/EAGE salt model prove that our common-azimuth migration approaches are effective in both depth and tau domains. Two real data examples show the advantages of wave-theory based prestack migration methods in accuracy and imaging resolution over the conventional Kirchhoff integral methods. Translated from Oil Geophysical Prospecting, 2006, 41(6): 629–634 [译自: 石油地球物理勘探]     

黄河上游云凝结核观测研究

分析了2001、2001年8月在黄河上游的玛曲－河南县利用美国Mee公司的130型云凝结核计数器观测的资料，讨论了凝结核的谱型，浓度随饱和度、天气状况及一些气象要素变化的关系，通过与其它地方观测结果的比较，可以看出在地表植被较好的黄河上游牧区，人类活动、污染较少，其自然凝结核少，浓度与青岛的测值相近，与海洋过饱和核谱型接近。     

Hydrothermal Alteration Zoning and Kinetic Process of Mineral-Water Interactions

This study reports the kinetic experimental results of albite in water and in KCI solution at 22 MPa in the temperature range of 25 to 400℃. Kinetic experiments have been carried out in an open flow-through reaction system (packed bed reactor). Albite dissolution is always incongruent in water at most temperatures, but becomes congruent at 300℃ (close to the critical point 374℃). At temperatures from 25 to 300℃, the incongruent dissolution of albite is reflected by the fact that sodium and aluminum are easily dissolved into water; from 300 to 400℃ it is reflected by silicon being more easily dissolved in water than Al and Na. Maximum albite dissolution rates in the flow hydrothermal systems have been repeatedly observed at 300℃, independent of flow rates.The kinetic experiments of albite dissolution in a KCl aqueous solution (0.1 mol KCl) indicate that the dissolution rate of albite increases with increasing temperature. Maximum silicon release rates of albite have been observed at 400℃, while ma