1984, 6(4):1-3.
Abstract:1954年2月11日山丹大地震距今已有三十年了。在这三十年中,曾有不少地震工作者深入震区,对山丹地震进行了实地考察。后来也有不少学者对与这次地震有关的问题进行了研究。在今天,把这些研究作一回顾总结,对今后地震学的研究是不无裨益的。
Ma Xikang , Xue Shunzhang , Yu Mouming
1984, 6(4):4-10.
Abstract:The data which were recorded in geoelectrical stations near the epicenters of 16 earthquakes with magnitude of 5.1-6.9 showed some features as following:
(1) The spatial scale of the anomaly was approximately 100km from the epicenters.
(2) Majority of the anomalies showed the decrease in the tendency of variation of ρs and minority of them increase.
(3) There is a linear functions in the coordinate of Lg△T-M(△T means the duration of the anomaly).
In addition, the relationship between the ρs-anomaly and the source-stress field as well as other precursors is discussed in the paper, and the problem of distinguishing between the ρs-anomaly and the annual change in ρs is also dealt with.
Lu Guangting , Tang Quan , Li Liuyu , Zhao Guangkun , Hu Cunde , Jiang Xuyuan
1984, 6(4):11-19.
Abstract:In this paper, the experimental results on P wave kinetic characteristics of sandstone under uniaxial compression are particularly introduced. Th kinetic parameters include the amplitude, the vibration continuous time, the amplitude spectrum, the coda trail continuous time and the attenuation coeffieient.The effect of water on these parameteres has been studied. The results are:
1. The maximum amplitude and the vibration continuous time were increased with the compression increase, both quickly decreased near the extreme failure.
2. The low frequncy compsition in P wave amplitude spectrum was increased with the compression increase.
3. The P wave kinetic characteristics were greatly affected by water. The existence of water decreases P wave amplitude and high frequency composition of amplitude spectrum.
4. The coda continuous time was increased and the attenuation coefficient was decreased with the compression increase.
Chief results in the experiment and their theoretical analysis are in agreement with the results observed in field-work.
These results would be of advantage to the discussion of precursor anomaly on kinetic characteristics of the seismic wave.
1984, 6(4):20-30.
Abstract:This paper advanced the important significance to measure nowaday elastic ground deformation and two kinds of palaeotectonic residual elastic ground deformation in earthquake prediction, introduced the principle and technic to measure these elastic ground deformation by X-ray diffractometry and analysed the measurement results in Chiansi region as well as the effect order of magnitude of palaeotectonic residual elastic strain energy for earthquake process and earthquake prediction.
Wang Zengjia , Chen Huacheng , Zhang Zhongfu
1984, 6(4):31-36.
Abstract:In terms of fuzzy logic theory, a new method which can synthefically Process the precursory information is presented. It can be applied to the short-term and immenent term prediction of earthquakes. It seems to the authors that the method used is convenient.
1984, 6(4):37-42.
Abstract:This paper was based on the field investigation of the Ganzi earthquake of June 16, 1982. There are three parts in the paper. The first part deals with source parameters, epicentral intensity, damage and deaths and injuries. The second part mainly describes the characteristics of the medium and long term premonitory anomalies. The third part discusses anomalous background, sensitive points, the density of Station distribution, instruments, main and secondary methods, synthetic prediction and so on. What the paper gives coucd be treated as an example in the study of premonitory anomalies and earthquake prediction.
1984, 6(4):43-48.
Abstract:In this paper, by applying the theory of dislocation for fracture and the conception of the force acted on the dislocation in stress field, the effect of horizontal tension region in the crust on the fault in earthquake source has been discussed. The formulas and the directions of the forces acted on the ends of the fault in earthquake source located in the tension region distributed radially have been derived theoretically. It is pointed out that tension region has the effect similar to image force for the fault in earthquake source. Under certain dispositions, this effect is to the benefit of propagating of fracture and cause the change of the propagating direction to the fracture. When the bottom of the crust is acted by certain distributed vertical forces, horizontal tension region will be produced at the surroundings. So, according to the datum of surface deformation of the crust and the geological condition around the fault in earthquake source, we could find out the possible existence of tension region and analyse it's possible effect on the fault in earthquake source.
1984, 6(4):49-56.
Abstract:The continual testing observation was carried out in Haiyuan, Ninxia from June to December 1982. Five observationary points along two observation lines were arranged. The current was about 70-100A, and the accuracy of observation for the current about 0.5%. We observed the man-made potential difference using a small instrument car once a day and twenty pulses of the potential were observed every time, and the accuracy of observation of the potential was about 3%.
The results have shown that in the resistivities observed at all the observational points occurred abnormalities of total change of 8-20% before the earthquake Ms=2.7 in Haiyuan on August 14,1982(epicentral distance was about 17km), meanwhile the abnormal change observed by the four-pole symmetric observation which is used to survey the resistivity of shallow layer was only about 1.5%.
There were other anomalies recorded at the observational site with the total change of 7-9% in geoelectric resistivity before another earthquake(Ms=3.3, Nov. 5,1982)in the north of Tongxin, Ninxia, which was 11okm from the observational site. It seems to the author that the anomalies could be explained on the basis of the hypothesis that there would exist a layer in the crust, where the precurssor is stronger than inother region of the crust in the preparing process of earthquakes and which is called the precursor advantageous layer proposed by Mr. Guo Zengjian.
Zang Ximing , Liu Jinyong , Yang Junfeng
1984, 6(4):57-61.
Abstract:The features of the abnormal sudden changes of ground tilt before earthquakes, statistical relationships between the duration of the sudden change to its peak value and the interval from the start point of the anomaly to earthquake occurrence and emperical relationships between the composite vector of the sudden change and the epicentral position are tentatively discussed in this paper. The conclusions are the following:
(1) Doubled time from the starting point of the sudden change of ground-tilt to its peak value plus a constant equals the interval between the starting point and occurrence of earthquake.
(2) The composite vector of the sudden change of ground tilt directs mostly to the epicenter, or back on the opposite direction.
(3) Generally the longer the duration of the abnormal sudden change of ground tilt and the bigger the abnormal change, the greater the magnitude of earthquake after the anomaly.
1984, 6(4):62-66.
Abstract:Many structure profiles and other geological marks of some ancient earthquake traces have been discovered in the region of Dahe flatland, Xiaodonggou ridge of Changma fault zone. In this paper, a brief description and analyses of the incidents of ancient seismic activities, which are revealed by the traces, have been done. The author believes that Changma fault zone would be a good place in which the ancient seismic activities can be deeply studied.
1984, 6(4):67-71.
Abstract:With regard to the application of computer to the digitized precursor observation system of earthquake, the fore-most problem is to collect data real-timely.In this paper, we introduce the digitized precursor real-time collection program, which can respond interruption, collect data real-timely, make many-function judge and treatment for the collected data, and they are read in data magnetic tape after they are arranged according to certain pattern under the support of computer DJS-131 made in China and under the control of real-time operating system. This program is mainly used in precursor observation system of telecommunication transmission earthquake stations. The dea and the skill of designing the program can be extended to other systems of collecting data real-timely.
Zhao Jialiu , Wang Yanqiong , Hou Yuanwen
1984, 6(4):72-76.
Abstract:Model PZ40 data processor is the specific digital recorder and processor for Model PZ40 digital earth-resistivity equipment. It can print the values of the natural potential difference Vmn and the supply current obtained in the measurement of earth-resistivity, and can calculate earthresistivity ρs for K=1 as well.
1984, 6(4):77-82.
Abstract:This paper presents concrete applying of equation of jumping of flip-flop in the design of the counting circuit. We apply the method in the analysis of counting circuit in the early days of the developing the instrument, improves the circuit and design a simple, stabilizing and reliable series counting circuit.
1984, 6(4):83-88.
Abstract:This paper presents a new method by which the density of radon in ground water could be continuously and automatically measured on the basis of Gas-Water phase equilibrium principle of radon. In the paper the author deduces the mathematics expression for the method, discusses its sensibility and time response etc., and compares the theory with experimental results attained by water-radon measuring apparatus based on this principle. The results show that this new method can meet with the requirments of observation of radon in earthquake prediction and geological circles.
1984, 6(4):89-96.
Abstract:In 1957, the first seismic risk zoning map of China was published[1]. The two principles of making the map were stated as follows.
l.The earthquake magnitude which appeared in history will repeat again in future.
2.Similarity of seismotectonics is corresponding with the similarity of earthquake magnitude.
The above mentioned principles have some insufficiencies. In this paper, some improvements on the seismic risk zoning have been discussed.
1984, 6(4):97-101.
Abstract:1973年6月3日新疆精河县内发生的Ms=6.0级地震是北疆地区七十年代以来发生的最大一次地震。震中位置:φN44°32',λE83°24';震源深度约30公里;发震构造为准噶尔南沿大断裂。这次地震有感范围颇大,东至乌鲁木齐,西至伊宁、霍城,都感到明显震动。
1984, 6(4):101-107.
Abstract:笔者将各地地震记载视为各地震台站的记录资料,对照谢毓寿教授的"新的中国烈度表"和李善邦教授的"历史地震烈度五条补充规定",确定各地遭受地震影响的强度——烈度,用现今地震所造成的烈度分布(影响场)特点进行类比,反推历史地震震级等参数。
1984, 6(4):107-109.
Abstract:重力预报地震的数据虽有多种,但它们的物理实质是一样的[1]。因此,我们日常工作中只使用日均值和潮汐因子δ值。日均值能反映震前地壳的快速蠕滑过程1),δ值反映了震前趋势的变化2)。我们将日均值作为短临预报指标,将δ值作为中长期预报指标。
Sopyright:China Earthquake Engineering Journal