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1.
2.
In this paper, the methods of pattern recognition and fuzzy cluster are applied to estimate comprehensive whether there would
be an earthquake which magnitude is commensurate with (N=M
0±0.3) or greatM>M
0) thanM
0 within 3 months using sequential data in 3 days immediately after a moderate or strong earthquake (M
0≥4.7) occurred, The result of retrospective test indicates that the comprehensive judgment effects by using these applied
mathematics methods are better than that of using every individual method obviously. TheV mark value of algorithm CORA-3 in pattern recognition is the highest among them. There are 44 known earthquake sequence data
(5 type- I and 39 type- II) used to learn and train, the results of internal coincidence test show that all 44 sequence samples
could be distinguished correctly. Extrapolation test by using other 4 known earthquake sequences (2 type- I and 2 type- II)
shows that all 4 extrapolation samples could be distinguished correctly also. In the process of study, these methods have
been applied to judge the post-earthquake tendency of 2 moderate earthquakes occurred recently, one is distinguished correctly
and the other wrong. The algorithm Hamming in pattern recognition and fuzzy cluster method have been applied to judge the
early post-earthquake tendency after a moderate or strong earthquake, too. TheV mark values of internal coincidence tests could get above 0.8 most cases of extrapolating are correct.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 15–21, 1993. 相似文献
3.
Qi-Jia Zou 《地震学报(英文版)》1993,6(3):739-747
The issuance of an earthquake prediction must cause widespread social responses. It is suggested and discussed in this paper
that the comprehensive decision issue for earthquake prediction considering the factors of the social and economic cost. The
method of matrix decision for earthquake prediction (MDEP) is proposed in this paper and it is based on the risk matrix. The
goal of decision is that search the best manner issuing earthquake prediction so that minimize the total losses of economy.
The establishment and calculation of the risk matrix is discussed, and the decision results taking account of economic factors
and not considering the economic factors are compared by examples in this paper.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismological Sinica,15, 232–238, 1993. 相似文献
4.
To actually reflect the seismic temporal-spatial inhomogeneity of intra continental strong earthquakes of North China in seismic
hazard analysis, several seismological and geological characteristics have been selected and quantized to describe the seismicity
features in time and space of every magnitude interval with the thought of dividing the interesting magnitude range into several
intervals and using of spatial probability distribution function. A component analysis method with orthogonal transformation
is introduced to avoid the repeated use of the same element and the subjective effects in determining the annual earthquake
occurrence rates of earthquake. By passing synthetic fuzzy judgement on the nonintercorrelated new characteristics, the annual
occurrence rates of every magnitude interval of each potential source area are obtained associated with the adjustments of
earthquake reducing process after the occurrence ofM>7 quake. An intensity map of the Beijing-Tianjin-Zhangjiakou area is calculated as an example which shows a close coincidence
with the seismic temporal-spatial inhomogeneity of North China.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 496–504, 1991. 相似文献
5.
The intterrelation among strong earthquakes and its application are emphatically studied in this paper. Taking North China
seismic region as study area, we have investigated how a great earthquake influence other strong earthqukaes in neighbouring
area? Does there exist earthqukae immunity phenomenon? If it exists, what distributional pattern did it has in space-time
domain? The results show that occurrence of earthquakes withM⩾7 has cetain immunity phenomenon to earthquakes withM⩾6 in North China. Among others, the immunity area of earthquakes withM=8 is much larger than that ofM=7. For earthquakes withM⩾8, the immunity area to the earthquakes ofM=7 is larger than toM=6.
Based on the above analysis, using some statistical methods, we gave the variational regularity of seismic immunity factor
with space and time, and explored its concrete application in seismic hazard analysis.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 339–346, 1993. 相似文献
6.
According to geological tectonics and seismic activites this paper devided North China (30°–45°N, 105°–130°E) into four areas.
We analyzed the North China earthquake catalogue from 1970 to 1986 (from 1965 to 1986 for Huabei, the North China, plain region)
and identified forty-two bursts of aftershock. Seven of them occurred in aftershock regions of strong earthquakes and seventeen
of them in the seismic swarm regions. The relation between strong earthquakes with the remaining eighteen bursts of aftershocks
has been studied and tested statistically in this paper. The result of statistical testing show that the random probabilityp of coincidence of bursts of aftershock with subsequent strong earthquakes is less than six percent. By Xu’sR scoring method the efficacy of predicting strong earthquake from bursts of aftershock is estimated greater than 39 percent.
Following the method proposed in the paper we analyzed the earthquake catalogue of China from 1987 to June, 1988. The results
show that there was only one burst of aftershock occurred on Jan. 6, 1988 withM=3.6 in Xiuyan of Northeast China. It implicates that a potential earthquake withM
S⩽5 might occur in one year afterwards in the region of Northeast China. Actually on Feb. 25, 1988 an earthquake withM
S=5.3 occurred in Zhangwu of Northeast China. Another example is Datong-Yanggao shock on October 18, 1989 which is a burst
of aftershock. Three hours after an expected shock withM =6.1 took place in the same area. Two examples above have been tested in practical prediction and this shows that bursts
of aftershocks are significant in predicting strong earthquakes.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 273–280, 1991.
Part of earthquake catalogue is from Jinbiao Chen, Peiyan Chen and Quanlin Li. 相似文献
7.
The method of reconstructing a phase space with higher dimensions can be applied to analysing the observaiton data for studying
the dynamic behavior of seismic processes and earthquake prediction. It is found that seismic processes are chaotic. So earthquakes
could be determinately predicted only within the predictable period. Here, some related problems (e.g. several primary parameters
and the relations among them, the relation between the quality of used data and analytical results, the relation between a
reductive process of the fractal dimensions and earthquake prediction and so on) are discussed.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 470–476, 1993.
This study was sponsored by the Chinese Joint Seismological Science Foundation under Contract NO. 9000007. 相似文献
8.
The digital seimograph network set up by China and France in Zhangye of China had been operated in 1988. The Zhangye network
is situated in the middle segment of Hexi corridor and Qilina mountain, which was regarded as a monitoring earthquake area.
Using the records of Zhangye digital network theQ-values in and around Minle basin have been measured. The results of this study showed that theQp-values range from 500 to 780, andQs-values range from 230 to 460. TheQ-values of inside of Minle basin are higher than that around the basin. The greater parts of moderate and strong earthquakes
occurred along tectonic belts around the Minle basin. Moreover, TheQ-values increased with the depth of penctration of wave ray. The attenuation of S wave is stronger than P wave in shallow
layer of crust. Some problems ofQ-value change versus time before and after Sunan eathquake (M
s=5.7) have been also disscussed. These results can be applied to study and to monitor seismic danger of the Minle monitoring
area.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 296–302, 1993. 相似文献
9.
In this paper, the major idea is: when seismic stress accumulates to a certain extent, a stick slip earthquake will occur
on the fault plane. The seismic stress before and after the stick slip earthquake occurrence are both stochastic variables.
According to this idea, the model of double bounds of stochastic stress is proposed, and also it is used to analyse the seismic
risk of Xian Shui River Fault Zone in the coming 30 years, the result is similar to what the Seismological Bureau of Sichuan
Province has predicted.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 477–483, 1993. 相似文献
10.
In this paper, first discussing briefly the instantaneous spectrum theory. Then, the instantnaeous spectra and Fourier spectra
of three seismic sequences are calculated, and comparing them to explain the superior characteristics of instantaneous spectrum.
Finally, the earthquake tendency of North China is estimated by using the instantaneous spectrum theory. The results show
that not only the occurrence time of the coming large earthquake, but also its magnitude instantaneous can be estimated by
using instantaneous spectrum of the seismic sequence.
The Chinese version of this paper appeared in the Chinese edition ofActa seismologica Sinica,15, 68–75, 1993. 相似文献
11.
By use of the specialized under ground electrodes as the sensor, the Experimental Multi-station Network observed Seismic Electromagnetic
radiationsprior to the moderately strong earthquake. From the great number of electromagnetic anomalies recorded by the network continuously
for about 10 years, it can be sure that the anomalies are related to earthquakes aboveM
s 5 within 300 km. The stronger the magnitude of the earthquake is, the better the relation is. The abnormal electromagnetic
radiation information appears in a short-time before the moderately strong earthquake. The continuous automatic pen recording
shows that the electromagnetic information is the waveform of the paroxysmal wave group, and has the features of undulating
enhancement, amplitude in inversely proportion to epicentral distance, frequency increase, regional similarity of wave froms
and directivity, etc.. It also contains some quantitative elements related to the parameters of the earthquake. The above
characteristics and correlative elements can provide important bases for predicting the three elements of the earthquake.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 83–90, 1993.
Associate Professor Da-Yuan CHANG and Teacher Feng CHEN have gave us a lot of help during the study. 相似文献
12.
Based on Generalized Seismic Ray Theory (Helmberger, 1968), a new quickly linear inversion method from the data of seismic
waveform to seismic moment tensor and source mechanism for domestic earthquake is studied in this paper. Six moderately strong
earthquakes which occurred in Chinese mainland in the past few years are studied. The seismic source parameters of these earthquakes,
seismic moment tensors, scalar seismic moments, fault plane solutions and source time functionsetc, are obtained.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 261–268, 1993. 相似文献
13.
14.
Since 1979 the repeated observations and experiments of geomagnetic total intensity and vertical component have been carried
out for ten years in the geomagetic network which is located in Jiangsu Province, China. Three earthquakes aboveM
s 5.0 occurred during the decade, and some seismomagnetic effects were observed. The observation results show that the anomalies
of the vertical geomagnetic component can’t be observed untill some months before the earthquake (M
s>5.0) in this area.
In this paper it is suggested that a densely distributed network for continuous observation of geomagnetic vertical component
may catch seismomagnetic anomalies and thus improve earthquake prediction in the light of the geomagnetic measurements of
the mid — or — low latitude locations.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 80–87, 1991.
This study is sponsored by the Chinese Joint Seismological Science Foundation. 相似文献
15.
Hu-Shuan Wang 《地震学报(英文版)》1993,6(3):705-712
Artificial Neural Network (ANN) model of computation based on mathematical model of neural processes is applied to establish
an intelligent computing network from seismic intensity to peak ground parameter instead of the conventional statistical relationship
in this paper. For a give seismic intensity rating, the network formed with actual strong ground motion records directly produces
the corresponding peak ground parameters and the effects of earthquake magnitude and epicentral distance are included. The
computed results of the network trained with a number of strong motion records in the West America show that such networks
have obtained good conversion relationship from seismic intensity to peak ground parameters.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 208–216, 1993. 相似文献
16.
In this paper, the relationships between seismic intensity and peak ground shaking are studied under no specific condition,
separately or simultaneously considering the number of building storey and site category, based on data of mean peak values
of horizontal ground motion recorded during strong earthquakes. Then, according to the statistical results, the variation
of mean peak value with intensity rating is discussed, and schemes of peak ground velocity, peak ground acceleration or response
spectrum of an designed earthquake converted from intensity rating are recommended. Finally, a methodology of converting seismic
intensity from response spectrum of design earthquake is also discussed, and the conversion scheme is recommended.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 32–40, 1991.
This paper is sponsored by the Chinese Joint Seismological Science Foundation. 相似文献
17.
Yun-Lin Zhang Hai-Jing An Xiao-Ling Liu Yu-Lan Si Mei Jiang Wu-Si Zhang 《地震学报(英文版)》1993,6(3):675-683
The high accuracy, automatic, digital MT measurement system with five electromagnetic components was firstly adopted by the
author to the section MT monitor and measurement in the middle Qilian mountain in the Northwestern China, the more real precursory
information of impending earthquake electromagnetic rediation of GongheM=7.0 earthquake (April, 1990) in Qinghai province was obtained by the system.
The new complete quantification frequency analysis was firstly used in this paper in both time and space domains for the analysis
of repeated measurement data at all sites.
This paper concludes the precursory spectral characteristics of electromagnetic radiation before strong earthquake as following:
1. The spectra appears as the synchronous electric field interference type mainly of conduction current; 2. Narrow band (0.5
– 20s) of spectral period; 3. The singularity of amplitude (the pulse amplitudes of interference electric field is 102 times the normal values); 4. They show the directionality of preparing focus to some extent; 5. The intermittent of radiation
(three peak periods appeared three days before the main shock). It is more significant that there existed a relative quiet
period of about 48 hours between the peak period and the occurrence, observators can response quickly at observational sites
and take it as one of the observational criterions for impending prediction.
This paper also points out that the impending earthquake electromagnetic radiation obtained by the MT measurement system is
mainly the conduction current, and the high-conductive layer existed commonly in the crust may serve as the better paths for
the conduction current circuit and enables the far away MT measurement sites to receive it.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 186–193, 1993. 相似文献
18.
In this paper, the coefficients of Parkinson vectora, b and the in-phase partA
r, Br and quadrature-phase partA
i, Bi of transter functions are calculated by using two kinds of data processing methods, respectively. The results of both methods
are close to each other. All these six parameters above are low in value, showing that the electric structure in Heze area
is rather uniform. It seems that the anomalous changes appeared in both results, and the values of parameters decrease before
and after Heze earthquake.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 113–120, 1991. 相似文献
19.
In the paper, the feature of strong earthquake orderly distribution in time, space and intensity before the Western Kunlun
Mountain Pass M=8.1 earthquake is preliminarily studied. The modulation and triggering factors such as the earth rotation, earth tides are
analyzed. The results show that: the giant earthquakes with the magnitude more than 8 occurred about every 24 years and the
earthquakes with the magnitude more than 7 about every 7 years in Chinese mainland. The Western Kunlun Mountain M=8.1 earthquake exactly occurred at the expected time; The spatial distance show approximately the same distances between
each two swarms. The earth rotation, earth tide, sun tide and sun magnetic field have played a role of modulation and triggering
in the intensity. At last, the conditions for earthquake generation and occurrence are also discussed.
Foundation item: State Key Project of Science and Technology of China (2001BA601B01) and State 863 Plan of China. 相似文献
20.
Based on fracture mechanics, large amount of practically observed data is analyzed in this paper, and it is disclosed that
seismically-anomalous earthquake resistivity sudden change sequence can be observed at the earth resistivity stations around
the epicenter of a strong event. The maximum sudden change in the sequence tends to shift backward with the increase of epicentral
distance, while it shifts forward with the increase of the magnitude of the earthquake. The maximum sudden change also expands
from the epicenter to the peripheral areas. Therefore, the authors propose that it might be possible to predict the 3 key
elements of a forthcoming earthquake by using the sudden change sequence, the frequency of the sudden change, the expansion
velocity of the maximum sudden change and the time-distance product.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 176–185, 1993. 相似文献