• Volume 5,Issue 1,1983 Table of Contents
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    • ON THE RELATION BETWEEN THE PLATE TECTONICS AND THE STRONG EARTHQUAKES IN THE TIBETAN PLATEAU

      1983, 5(1):1-8.

      Abstract (551) HTML (0) PDF 694.67 K (468) Comment (0) Favorites

      Abstract:According to the space distribution of ophiolite suit, melange blueschist and deep-great fault zone in the Tibetan plateau, five suture zones of different periods are divided. They extend in belts and with Nww trends, which turn to SN direction at their east end. The geological age of these suture zones of plate is from the early palaeozoic the cenozoic era. Except the Yarlung zangbo jiang belt, the rest are the suture zones of paleoplate, which still had activities in the quaternary period.
      Based the distribution characteristics and migration regularity of strong earthquakes (Ms≥6) studied region, the author of this paper suggests that those seismic belts coincide with both the distribution of young suture zone of plate and that of active suture zone of paleoplate. The generation of the earthquake is related to the collision of the Indian and the Eurasian plates. It is also related to the activities of mantle material, but the sutures of plate only function to control the earthquakes.

    • PRE-EARTHQUAKE CHARACTERISTICS OF B VALUES FOR SOME INTERMEDIATE MAGNITUDE EARTHQUAKES IN THE TIANSHAN SEISMIC REGION OF XINJIANG

      1983, 5(1):9-17.

      Abstract (541) HTML (0) PDF 689.36 K (469) Comment (0) Favorites

      Abstract:In this paper, the pre-earthquake characteristics of b values for the intermediate magnitude earthquakes in the Tianshan seismic region of Xinjiang are studied. It was found that since 1971, the phenomena of seismic deficiency had occurred very often in the b values of the earthquakes (M>5.5) for some years before earthquakes. The interval of seismic deficincy was in good agreement with the magnitudes of happening earthquakes In the same way, the abnormal low b values would often exist in the intermediate earthquake (M>4.8), the abnormal time and the proelnet(β) of abnormal amplitude related to magnitude and we can make use of their relationships to assess the magnitude for future earthquakes. It was also found that the b values of the aftershock sequences of intermediate magnitude earthquake and of small earthquake swarms were in a low state before some time of the next one in this region and it was so even before several years of strong earthquakes. From all mentioned above, we came to the conclusion:the b value has a direct sense in physics, and the low b values, which are the reflection of fluctuating stress state, are a signal for possible occurring of strong earthquakes.

    • THE MECHANICAL INTERPRETATION FOR THE PRECURSOR ANOMALIES OF GROUNDWATER LEVEL DURING TANGSHAN EARTHQUAKE AND ITS RELATIONSHIP WITH FOCAL EVOLUTION PROCESS

      1983, 5(1):18-24.

      Abstract (522) HTML (0) PDF 568.65 K (609) Comment (0) Favorites

      Abstract:This paper deals with the forming mechanism of groundwater level anomaly in the Tianjin——Tangshan region, the interprectation for the mechanical process as well as its relationship with forcal evolution process. It suggests that in the Tangshan epicentral area there was the horizontal tensile stress derived from vertical-up force in focal process and in the Tianjin area there was the vertical-down drag force in the Earth's depth. This led to the long-term descent of groundwater level. Before shock the feedback effects focal stress field was enhanced in the Tianjin region. Therefore, the horizontal drag force in the Earth's depth was resisted, the observed water——bearing bed was compressed reversely. Meanwhile due to the preseismic slip before the main fracture in the epicentral area the focal stress field turned and the stress condition of observed water-bearing bed changed, as a result the groundwater levels suddenly rose up just before shock. The observed water-bearing bed, which is above earthquake source in Tangshan and near earthquake source in Tianjin, is located in hard limestone and in loose layer, respectively. Their hydrogeological mechanical conditions are different. It shows that the anomalistic process of groundwater level is an unitized mechanical process of brewing earthquake in which there are various descending rates of groundwater level. Finally, the relationship between Tangshan groundwater level anomalies in epicentral area and focal evolution process is discussed.

    • THE MARCH 2.1979 GUZHEN EARTHQUAKE(Ms=5.0)

      1983, 5(1):25-30.

      Abstract (531) HTML (0) PDF 636.41 K (518) Comment (0) Favorites

      Abstract:In this paper, the main shock parameters of the March 2.1979 Guzhen Earthquake, the seismicity before the main shock and the characteristics of the earthquake sequence are studied. The results show that before the main shock, the seismic gap formed by some small earthquakes exists in a nearby region around the epicenter of the main shock. After the formation of this gap, the frequency of small earthquakes, the value of b, the strain release, etc. show anomalous changes. The velocity ratio in a certain area before the main earthquake shows anomaly too. On Feb. 17.1979, a set of earthquakes with some information about the mainshock occurred on the edge of the gap.
      The survey of the aftershock sequence is introduced in this paper. And it is pointed out that the sequence is characterized by the stable source mechanism and the lower b value which are different from other general aftershock sequences.

    • ON THE LATERAL CHANGE CHARACTERISTICS OF CONDUCTIVITY DISTRIBUTION OF EARTH'S CRUST AND UPPER MANTLE IN SOME REGIONS OF NEIMENG, GANSU, NINGXIA

      1983, 5(1):31-42.

      Abstract (532) HTML (0) PDF 943.30 K (524) Comment (0) Favorites

      Abstract:This paper has given the MTS results in some regions of Neimeng, Gansu, Ningxia. It further demonstrates the conclusion about the presence of the anomaly low resistivity layer in the median earth crust of the seismic zone. It also shows that in the northern section of the South-Northern Seismic Belt the first low resistivity layer in upper mantle appears the zonal lift.
      These results show that in the seismic zone the lateral changes of electrical distribution in the earth's crust and upper mantle are very remarkable, in the more stable Eerduosi Platform the lateral changes of conductivity distribution are less, and the electrical construction of the. earth's crust and upper mantle is simpler.
      On the basis of these results it is found that a low resistivity layer in the upper earth's crust(~10-15km) appears clear in centrum regions of the stronger earthquakes, probably, it is related to stronger earthquake. The MTS results in Northwestern China show that M-interface is not a clear electrical interface, but the anomaly low resistivity layer in median earth's crust of some regions seems to be relative to C-interface, then it becomes a clear electrical interface.

    • PRELIMINARY EXPLORATION ON COMMENSURABLE CHARACTERISTICS OF STRONG EARTHQUAKE ACTIVITIES IN SOUTH XINJIANG

      1983, 5(1):43-52.

      Abstract (480) HTML (0) PDF 601.82 K (880) Comment (0) Favorites

      Abstract:Based on "the idea that commensurallity means the extension of periodicity," we have made different statistics in different regions for the strong earthquakes, Ms≥6.0, in South Xinjiang. It has been found that the commensurability of strong earthquake activities exists nearly in every region, and in most eases the results are satisfactory, only with a few exceptions in which errors are large. We have also found that the effect is clear from a point of view of the statistics, and that the relative error, which is free from the prediction period, is a normal distribution by means of assumed test. And. the most important thing is that there is a period of about eleven years as a least common multiple for the different commensurable values in each region, which appears to be a better characteristic of the commensurability.
      In spite of some false reports, we still think it practical for the trend estimation of strong earthquake time the to make use of commensurability. In fact, good results were obtained in middle period prediction for the Xikeer earthquake of magnitude 5.7 on Dec.19, 1977, and the Kuche's, 6.0, on March. 29, 1979.

    • PRELIMINARY STUDY OF THE RELATIONSHIP BETWEEN STRONG EARTHQUAKE ACTIVITIES AND BLOCK MOVEMENT IN WESTERN SICHUAN PROVINCE

      1983, 5(1):53-59.

      Abstract (476) HTML (0) PDF 620.75 K (623) Comment (0) Favorites

      Abstract:This paper deals with the characteristics of strong earthquake(M>7) activities in western Sichuan province, in the light of the block movement. These activities are characterized by clear lumping, occurring in pairs and trending short in tectonics and time At the same time, the new division method is presented for the seismicity period there since 1900. It is certainly significant for mid-large-range forecast.

    • A DUAL PHENOMENON OF STRONG SHOCK ACTION IN SOUTHEAST CHINA

      1983, 5(1):60-65.

      Abstract (538) HTML (0) PDF 535.58 K (920) Comment (0) Favorites

      Abstract:In Southeast China, strong shocks(M≥4(3)/(4)) often present dual activities along a fault zone.Along with the symmetric feature of rhombic and monoclinal types in geological structure, it reflects the symmetric feature of tectonic stress and crust movement. Because of the difference of some factors which affects the process of earthquake occurring, the difference between magnitudes of the two earthquakes in pairs reaches 0-1 M, the interval is from several months to near hundred years, and the distance of epicenters is 15-300km. These parameters are closely related to the regional concrete conditions.
      The strong shocks occurred in pairs make up 61 per cent of the total strong shocks in this region, during 1500-1977, it indicates that it has rather an universal feature that the earthquakes often occur in pairs. Therefore, the discovery is useful for earthquake prediction.

    • DEPTH STRUCTURE OF THE WESTERN REGION OF GANSU PROVINCE

      1983, 5(1):66-71.

      Abstract (499) HTML (0) PDF 543.60 K (753) Comment (0) Favorites

      Abstract:In this paper, the crustal thickness of the western region of Gansu province is inverted by means of gravity data and single crustal model. According to Airy isostatic hypotheses, a computation of isostatic compensation has been made and a map of M surface and a map of isostatic anomaly drawn up.
      The force source formed on the crustal variation belt of the western region of Gansu province is briefly discussed.In the light of the historical data of earthquakes, the relationship between crustal structure and isostatic anomaly and the earthquakes is discussed.

    • CHARACTERISTICS OF ACTIVE STRUCTURES OF LONGSHOUSHAN AREA IN GANSU PROVINCE

      1983, 5(1):72-78.

      Abstract (554) HTML (0) PDF 619.57 K (698) Comment (0) Favorites

      Abstract:In this paper, based on the facts of the crust structure and the distribution of active fractures and vertical motion of massif in the Longshoushan area, the authors have studied the active way of areal crust and analysed principal compressional stress direction in this area. The conclusions of this paper are tested and verified by measurement data.

    • ON THE LONGXI ROTATING-ROLLING TECTONIC AND THE RELATION BETWEEN THE TECTONIC AND EARTHQUAKES

      1983, 5(1):79-84.

      Abstract (571) HTML (0) PDF 550.23 K (1107) Comment (0) Favorites

      Abstract:In this paper, the author goes into the details of the characteristics which show how the Longxi rotating-rolling tectonic is dictributed. It is believed that this tectonic is distributed among the Qinghai-Xizang massif, the Alashan massif and the Eerduos massif. It may be divided into five cycle tectonic belts. They are the Liupanshan Mountain-the Nanhuashan and the Xihuashan Mountains-the Maomaoshan Mountain, the Xiang shan Mountain, the TanShan Mountain-the Yaoshan Mountain-the Yantongshan Mountain, the Daluoshan and the Xiaoluoshan Mountains and the Qinglongshan Mountain. They congregated to the Guyuan-Baoji area and scattered Northwestward. Two sides of principal cycle surface moved in counterclockwise rotation.
      This tectonic was clearly shown on the satellite picture and still moves at present. Earthquakes(Ms>7)often depend on it and moves from the outer cycle belt to the inner and the magnitude of these earthquakes is getting greater and greater.
      The author holds that the formation of the Long ting-rolling tectonic is the result of the movement of the Qinghai-Xizang massif and the Eerduos massif.

    • VARIATION CHARACTERISTICS OF P-WAVE VELOCITY IN THE SANDSTONE UNDER UNIAXIAL COMPRESSION

      1983, 5(1):85-90.

      Abstract (569) HTML (0) PDF 451.03 K (488) Comment (0) Favorites

      Abstract:The rocks of parallel bedding and vertical bedding were loaded under uniaxial compression until stable was kept about 95 percent of failure intensty of the specimen. When the specimen were full of water or dry, the variation characteristics of p-wave velocities interior and saturated specimen observed were as follows:
      1. Changes of p-wave velocities were quite different in both direction of parallel bedding and that of vertical bedding when the rock would soon become a failure.
      2. The amplitude of p-wave and its shape varied with ever-increasing stress.

    • ON THE GENERAL MODULATION MODEL FOR IMPENDING EARTHQUAKE PREDICTION

      1983, 5(1):91-98.

      Abstract (514) HTML (0) PDF 460.39 K (538) Comment (0) Favorites

      Abstract:In 1978, we based on the temporal fluctuation of precursors preceding the 1975 Haicheng earthquake with magnitude 7.3 to propose the modulation mode[1]. This model combined the source process with both external factor action and precursor in causation. From this model we had discussed the preliminary way toward the earthquake prediction with accuracy of day. In 1980 and 1981, we discussed farther this model and forcasting[2][8].This paper will generalize the modulation model and present a lot of examples for earthquake prediction.

    • PREMONITORY VARIATIONS OF DYNAMIC CHARACTERISTICS OF SEISMIC WAVES IN MEDIUM OF EARTHQUAKE PREPARATION

      1983, 5(1):99-118.

      Abstract (502) HTML (0) PDF 1.07 M (812) Comment (0) Favorites

      Abstract:本文从理论上与实际资料分析上入手,较系统而广泛地研究了强震及中强震前地震波的动力学特性。
      首先,选取多相介质模型来模拟乎震区的舍裂隙岩石。在两相介质情况下用传波理论研究了地震波动力学特性,如振幅和皮形的一般变化。所得的理论结果表明,P波、S波、面波及尾波等的振幅、振动特续时间,周期或频谱等在大震前均可能出现某些前兆异常变化。
      其次,借助于观测资料,本文介绍了探索地震波动力学特性前兆异常的一些有效处理方法。特别使用了对尾波和短周期瑞雷波的前兆异常的分析处理方法。除天然小震资料外,还使用了矿山人工爆破资料。作为例子,本文得到了在溧阳台(距M=6.0震中22公里),天平山台(Δ=190公里)和杭州台(Δ=220公里)从马鞍山铁矿爆破源(震中西北86公里)爆破中记到的直达波和反射波的新的资料结果,从中较详细地研究了P波和S波的振幅、振幅比、初动周期偏差和尾波的某些特性(相对走时,频率变化,振幅衰减及由尾波确定的Q值)。
      然后,本文利用大量的实际观测资料,具体剖析和研究了我国唐山(M=7.8)、海城(M=7.3)、松潘(M=7.2)、溧阳(M=6.0)及其它一些强震和中强震前的P波、S波、短周期而波和尾波的多种动力学特性(振幅、振幅比,初动周期偏差,波形和频谱,振动持续时间等)出现的前兆异常变化,在此基础上,初步归纳了地震波动力学特性前兆异常变化时空分布的一般特点,並与波速异常加以对比。
      最后,对所得的结果及其在地震预报中的应用作了简要的讨论。这里要着重指出的是,大震前地震波的某些动力学特性的前兆变化能明显地观测到。因此,如果同时使用地震波的运动学和动力学特性,我们就能得到更多的地震前兆信息。

    • >综合评述
    • ON THE RESEARCH OF EARTHQUAKE LOCATION

      1983, 5(1):119-122.

      Abstract (555) HTML (0) PDF 395.77 K (414) Comment (0) Favorites

      Abstract:在地震参数的测定中,对于震中经纬度和震源深度的测定,简称地震定位。地震定位的研究,是现代地震学研究的基本问题之一。随着应用数学和电子计算机的发展及其在地震学领域的应用,以及地震学本身观测系统的改进,才使得地震定位的研究有了很大的发展。同时,地壳和上地幔的研究成果也逐步用于改进地震定位的方法,这对提高地震定位的精确度是可以起到一定的作用的。

    • >研究报道
    • DISTRIBUTION CHARACTERISTICS OF CHINA'S INTERPLATE SHALLOW FOCUS EARTHQUAKES AND THEIR CORRELATION ANALYSIS TO INTERPLATE EARTHQUAKES

      1983, 5(1):123-127.

      Abstract (494) HTML (0) PDF 430.00 K (475) Comment (0) Favorites

      Abstract:传统大地构造学侧重于大陆的研究,忽视了海洋,而板块构造学则立足于海洋,对于大陆内部的板块划分讨论极少。对于大陆板块的逐级划分,早在板块学说问世之前就开始了,只不过当时采用的名称(如断块、块体、地块等)不同,没有与海底扩张理论联系起来。

    • THE INTERFERENCE EXPERIMENT OF EVIDENT DROP OF RADON CONTENT IN GROUNDWATER IN WUQUANSHAN, LANZHOU

      1983, 5(1):128-129.

      Abstract (553) HTML (0) PDF 167.28 K (373) Comment (0) Favorites

      Abstract:五泉山水化(水氡)观测站于1981年9月份正式投入观测,使用的仪器是自记测氡仪和FD-125型射气仪。水源为西龙口泉水多个逸出孔封流两路管道,一路引入观测站内做为自记测氡,一路在山崖上做为日观测取样。自1981年9月底以来,自记测氡值除数据间断外,大都在7.5-8.0埃曼范围内,但日观测的氡值却出现了显著的趋势下降(图1),下降幅度达21%。

    • PRELIMINARY STUDY ON ANNUAL CHANGES OF GEO-RESIS TIVITY

      1983, 5(1):130-133.

      Abstract (576) HTML (0) PDF 295.14 K (415) Comment (0) Favorites

      Abstract:从一九六八年开始,甘肃省内先后布设和改建的地电台共有十七个。采用的基本都是四极对称法;供电极距最长为一千五百米,多数在一千米左右;观测仪器大都是DDC-2A型电子自动补偿仪,仅在兰州和临夏两台长期使用精度在万分之五的直流数字电压表;多数台长期观测误差在1-1.5%之间。

    • A DISCUSSION OF THE CAUSE OF THE CHANGES OF GROUNDWATER LEVEL IN YUZHONG AREA IN 1980

      1983, 5(1):134-136.

      Abstract (510) HTML (0) PDF 266.77 K (582) Comment (0) Favorites

      Abstract:1980年榆中地区较为干旱,年降雨量不足多年平均降雨量的一半。但该区自1980年10月份以来地下水却普遍上升,一些泉水水质逐渐变坏,以致不能饮用。这是否是地震前兆反应,引起了有关部门的关注。为此我们进行了实地考查,目的在于及时地找出变化的原因,为地震预报提供可靠的依据。

    • >讨论
    • GASIFICATION AND EARTHQUAKE

      1983, 5(1):137-138.

      Abstract (492) HTML (0) PDF 202.52 K (424) Comment (0) Favorites

      Abstract:地震成因是人们很关心的问题,因为它与地震预报密切相关。但这个问题很复杂,目前学说很多。本文拟讨论气化性地震成因的观点,並试图用于地震预报。

    • >简讯
    • THE FIRST LECTURE CLASS ON THE THEORY AND APPLICATIONS OF SEISMIC WAVES WAS CONDUCTED IN LANZHOU

      1983, 5(1):139-139.

      Abstract (410) HTML (0) PDF 106.51 K (580) Comment (0) Favorites

      Abstract:1982年10月30日至11月8日,国家地震局委托兰州地震研究所在兰州举办了一次地震波理论与应用讲习班。国家地震局所属分析预报中心,各研究所、地震学校、物探大队、各省局及云南大学等共30个单位,87名代表参加了这次讲习班,中级科技人员接近半数。

    • >学术活动
    • SCHOLARS OF THE UNITED STATES, AUSTRIA AND SWEDEN VISITED LANZHOU AND GAVE LECTURES

      1983, 5(1):140-140.

      Abstract (310) HTML (0) PDF 100.24 K (463) Comment (0) Favorites

      Abstract:美国地质调查局著名地质学家华莱士(Wallace,R. E)博士及巴克纳姆(Bucknam,R. C)博士在北京参加大陆地震活动和地震预报国际学术讨论会之后,于1982年9月19日到达兰州,对兰州地震研究所进行了为期三天的访问,在访问期间,外宾们应邀作了学术报告,参观了兰州观象台和五泉山水化观测站,同本所部分科技人员进行了学术交流。

    • >新书介绍
    • A REVIEW ON “APPLICATION OF FUZZY MATHEMATICS”

      1983, 5(1):141-141.

      Abstract (533) HTML (0) PDF 94.49 K (497) Comment (0) Favorites

      Abstract:模糊数学方法是近年来迅速发展起来的新的应用数学方法。由于用它们来分析处理各类经验性的信息与模糊研究对象时具有简单方便,便于运算和利于吸收人的智慧与经验等优点,这些方法已在自然科学和人文科学的许多领域内开始得到广泛的应用。近年来,模糊数学方法已引用到地震研究当中。

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