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1.
The diurnal periodicity of seismic events of different energy from the Greece earthquake catalog was studied. Earthquake samplings of different energy with a known level of magnitude of completeness were compiled. Parameters of the diurnal periodicity of earthquakes in different time and magnitude intervals were analyzed. Significant diurnal periodicity of earthquakes with M ≤ 4.1 was revealed. The most important result of the paper is the discovery of the diurnal periodicity of the representative earthquakes with M = 3.2–4.1. The diurnal periodicity of representative earthquakes cannot be explained at the base of the prevailing hypothesis considering the diurnal periodicity of earthquakes as an apparent phenomenon resulting from diurnal changes in the real sensitivity of the seismic network due to diurnal variations of seismic noise. 相似文献
2.
V. I. Zhuravlev A. A. Lukk K. M. Mirzoev N. A. Sycheva 《Izvestiya Physics of the Solid Earth》2006,42(11):890-903
Data on the time moments and numbers of weak earthquakes (M ≥ 0) are analyzed in five regions of Central Asia where long-term extensive instrumental observations of seismicity were conducted. Spectra of time moments of seismic events were calculated in the range of periods from 1 to 48 h with a step of half an hour. The time variations in the numbers of these earthquakes were also calculated in windows of 4 to 48 h wide with a summation step of 1 h. The presence of significant high-quality spectral extrema at periods of 24 and 12 h is established for all catalogs used, and less significant extrema at a period of 8 h are established for some catalogs. These periodicities are observed in the analysis of weak earthquakes with M < 2.2 (K < 8) and are virtually absent for stronger seismic events. It is shown that lunisolar tides have no appreciable gravitational effect on the observed variations in seismic emission. Daily variations in the actual sensitivity of the observation network due to the daytime increase in the noise level as a factor responsible for the observed diurnal periodicity raise doubts. 相似文献
3.
A. Ya. Sidorin 《Seismic Instruments》2010,46(3):293-305
Analysis of earthquake catalogues on 14 world regions has revealed a distinct diurnal periodicity of seismic events in all
of them. The amplitude of the diurnal variations usually decreases with an increase in earthquake energy, although in some
regions, the time series of strong earthquakes also demonstrate diurnal periodicity. Earthquakes are more frequent at night.
The acrophase of the course of diurnal seismicity correlates with geographic longitude. The Rayleigh — Schuster hodographs
of diurnal periodicity demonstrate sharp changes (kinks) in the vicinity of the equinox and solstice moments. The annual hodograph
of the diurnal periodicity of earthquakes is distinctly divided by the equinox moments into segments with different slopes.
The defined segments differ in the amplitude and acrophase of the course of diurnal seismicity. The data imply influence of
the mutual positions of the Sun and Earth on seismicity in different world regions. Possible mechanisms responsible for such
influence are discussed. 相似文献
4.
We evaluate the contribution of the Arkhangelsk seismic network to the recording of seismic events of the Arctic region. The evaluation is performed by means of the general analysis of the network seismic catalog, evaluation of the magnitude sensitivity, and comparative analysis of the Arkhangelsk network catalogs with NORSAR seismological data services and the Geophysical Service of the Russian Academy of Sciences. It is established that the Arkhangelsk network has a rather high sensitivity and records the intra-plate and inter-plate seismic activity in the Arctic Region. Due to the start of the seismic station operation on the Franz Josef Land Archipelago, there is a capability to record earthquakes, data on which are missing in the catalogs of well-known seismological data services. 相似文献
5.
A. Ya. Sidorin 《Seismic Instruments》2014,50(3):246-267
The features of the diurnal periodicity of earthquakes with different energies in Japan are studied. The spatiotemporal parameters of different earthquake sets are investigated in detail using various techniques including analyses of amplitudes, dispersion, spectra and correlation. The phases of seismic flows are studied using the modified Rayleigh-Schuster method. Lomb-Scargle periodograms are used to study the frequency of variations in seismicity. The parameters of the sets of earthquakes having different energies obtained in this study indicate changes in phase of the diurnal periodicity of earthquakes to the opposite near the magnitude of completeness. The very clear midday effect is noted. 相似文献
6.
中国目前实行的区域地震台网独立运行机制,使得在相邻不同台网的交界地区可能存在多个版本的地震目录和震相观测报告,影响了地震活动性分析与研究.为此,本文提出了一种基于联合概率的方法,可标明两个或多个相邻台网目录中相同的事件,合并它们的震相数据开展重新定位,并重构不同台网交界地区的统一地震目录.该方法的思路与分析步骤是：首先,计算获得不同台网之间具有最小发震时刻差异的两两地震的时空强差异分布,查找并剔除独立地震,计算事件合并的联合概率;其次,基于联合概率分析合并不同台网的地震目录和震相观测报告,对合并事件进行重新定位和定位误差分析,并基于G-R关系检验重构目录的完整性.本文以2014年鲁甸地震序列为例的初步应用结果显示,震相合并之后的地震定位精度相比之前单个台网的结果,特别是相比四川台网的目录,定位精度提高非常显著,合并后的目录与之前相对完整的云南目录接近,但相比由两个台网目录简单拼凑而成的目录更加准确.此外,研究还发现在目录合并过程中,对于4级以上的中强震,应选择MS而不是以ML震级标度;震相合并后被复用台站记录的到时信息可用于检测不同台网间的震相拾取是否存在系统偏差.本文提出的方法使得在相邻不同台网的过渡区形成一个统一且尽可能准确可靠的地震目录成为可能. 相似文献
7.
This work is a certain stage in investigations devoted to the recognition and examination of the seismic process dynamics in order to assess prospects and elaborate recommendations for the prediction of very strong earthquakes. The work is based on the use of the second-order differential equation, the so-called equation of the dynamics of self-developing processes, as an approximation model. Nine seismic catalogs including information about more than 1.5 million earthquakes were analyzed. The time behavior of three parameters characterizing the seismic process development, namely, the number of seismic events, accumulated conventional strain, and total energy of the events, was examined in terms of the model approximation. More than 17 000 well-defined seismic sequences of activation and attenuation were revealed using these parameters. The sequences account for about 38.5% of the total number of earthquakes from the catalogs studied. The remaining earthquakes belong to sequences of stationary development (in the form of background seismicity and earthquake swarms) and ill-defined sequences of activation and attenuation. The presence of stable regular patterns in the nonlinear development of the seismic process in time makes this process basically predictable. However, additional investigations are required for direct practical use of the regular features revealed in this work. 相似文献
8.
A. Ya. Sidorin 《Seismic Instruments》2010,46(4):351-355
A search for technogenic effects in the time series of earthquakes in Greece is carried out. The ine- quality of intra-week distributions of earthquakes including the events of M ≥ 3.7 is shown. Sharp changes in the pattern of Rayleigh-Schuster’s hodograph for the diurnal periodicity of earthquakes were revealed. They are located in the time vicinity of the moments of the equinox. The result supports the idea of the natural gen- esis of the diurnal periodicity of earthquakes and the important role of the Sun. 相似文献
9.
A. Ya. Sidorin 《Seismic Instruments》2010,46(4):377-382
A search for technogenic effects in the time series of earthquakes in Greece is carried out. The ine- quality of intra-week
distributions of earthquakes including the events of M ≥ 3.7 is shown. Sharp changes in the pattern of Rayleigh-Schuster’s
hodograph for the diurnal periodicity of earthquakes were revealed. They are located in the time vicinity of the moments of
the equinox. The result supports the idea of the natural gen- esis of the diurnal periodicity of earthquakes and the important
role of the Sun. 相似文献
10.
A. Ya. Sidorin 《Seismic Instruments》2010,46(3):237-249
The catalog of earthquakes that happened in Greece over the period of 1964 to 2008 was used for the analysis of their diurnal periodicity in this region. The quality of the catalog was examined with the defining of the representativeness levels of earthquakes in different selections. The earthquakes, including relatively strong events with the magnitude M ≥ 4.0, demonstrate diurnal periodicity with seasonal differences in their course reflected in their higher summer seismicity as compared with the winter one. 相似文献
11.
A. V. Klyuchevskii 《Journal of Volcanology and Seismology》2010,4(4):274-283
The numerical modeling of actually observed events contained in the Baikal earthquake catalog allowed the production of synthetic
catalogs. These catalogs reflect real situations that can give rise to heterogeneities in earthquake catalogs acquired by
seismological monitoring. For each of the resulting 65 catalogs we calculated the slope γ and seismic activity (so-called
in Russian; it is the seismicity rate or the constant term in the frequency-size relation) A
10 in the recurrence relation. We also investigated the effects of changes in estimates of earthquake energy class on the parameters
of the recurrence relation. It was shown that the slope γ is not very sensitive, but that the seismic activity A
10 is sensitive, to changes in earthquake energy class and can be used to test an earthquake catalog for heterogeneity. Formulas
were derived to relate the parameters of recurrence relations and the scaling factors of two energy scales, which can yield
recurrence parameters for one of the scales, provided we know the ratio of the respective scaling factors and the recurrence
parameters based on the other scale. 相似文献
12.
地震目录资料是进行地震预测、地震危险性分析、地震活动性研究等地震学研究的基础资料.对地震目录资料的完整性可靠性分析是地震学研究的基础工作之一.近几十年来我国积累的大量的仪器地震记录,历史地震也在不断更新,为地震活动性研究提供了更为丰富的样本,因此有必要对新的地震目录进行完整性分析.本文采用了新的统计方法对我国仪器记录地震目录和历史破坏性地震目录进行了完整性分析.结果表明,对于仪器记录地震目录（M≥3.0）我国东部地区1975年后基本完整,西部地区1980年后基本完整.对于历史地震目录（M≥5.0）,东部地区1500年后基本完整,西部地区1950年后基本完整.考虑到华北地震区历史破坏性地震（M≥43/4）活动的时间非平稳性,我们采用突变点分析法研究了华北地震区历史破坏性地震目录的时间特征,得到了华北地震区地震活动周期性变化的突变点位置,并揭示了华北地震区历史破坏性地震目录完整起始时间约为公元1500年前后. 相似文献
13.
The catalogue of earthquakes recorded in Iran during 2006–2010 by a dense network of digital telemetric seismic stations is
analyzed. The spectrum of the time series of these earthquakes contains a sharp maximum at 24 h. The corresponding curve of
diurnal periodicity constructed by the superposed epoch method has a clear double-peak maximum near noon(11 a.m.-5 p.m. local
time), which exceeds the level of seismic activity observed during the rest time of the day by a factor of 3-3.5. In the same
time interval, the average hourly magnitudes of seismic events sharply drop from M = 2.15 to M = 1.95. The ratio of the normalized number of earthquakes in the daytime to those at other times of the day, which was determined
within a moving window half a square degree in size, has seven distinct compact spatially isolated maxima whose magnitudes
attain several dozens to a hundred units. These maxima are probably caused by industrial activity, such as road building and
quarry explosions. We also note the presence of the weekend effect when the daytime maximum in the weekly curve of diurnal
variations in seismic activity almost completely disappears on Friday, which is the weekend in Muslim countries. At the same
time, elimination of the supposed noise component from the catalogue by the approved technique changes nothing for the daytime
maximum in the daily pattern of earthquakes in Iran. In order to account for this inconsistency, we suggest invoking additional
information on the technogenic seismicity and considering weak earthquakes induced by quarry explosions and vibrations of
industrial machines, in particular, power units of numerous hydroelectric power stations distributed over the territory of
Iran. 相似文献
14.
15.
A. Ya. Sidorin 《Seismic Instruments》2011,47(4):368-385
The main features of periodic changes in the parameters of seismic noise, seismicity and electric power consumption in industrial
networks are compared to verify the hypothesis on the technogenic influence of electric network load on seismic noise and
seismicity and to search for possible origins of the diurnal periodicity in seismic emission processes discovered in various
regions of the world. Sufficiently good similarity of the compared processes is revealed that does not contradict the hypothesis.
However, there are also some important discrepancies. An inverse phase pattern of interdiurnal distributions of weak and strong
Japanese earthquakes has been found, and various possible mechanisms of this phenomenon, which had been observed earlier in
certain other regions, are discussed. 相似文献
16.
Cycles in mining seismicity 总被引：1，自引：1，他引：0
Henryk Marcak 《Journal of Seismology》2013,17(3):961-974
Stochastic models of self-organized criticality and intermittent criticality are used to describe the structure of seismic catalogs. The intermittent models introduce three phases of the seismic cycle: increase in seismic energy, seismic relaxation, and seismic quiescence after the final relaxation. In this paper, seismic mining catalogs from a deep copper mine are searched to find these three phases of the seismic cycle. In spite of the differences between the seismic records from earthquakes and the building of stresses in the mine, the cycles can be estimated in mining seismicity. 相似文献
17.
A. Ya. Sidorin 《Seismic Instruments》2011,47(1):89-92
A 15-min periodicity of seismic events in the catalog of earthquakes in Greece is discovered. It is most vividly expressed
in the time series of weak and shallow events; however, it also occurs in the series of rather strong representative and deep
earthquakes. 相似文献
18.
A. Ya. Sidorin 《Seismic Instruments》2012,48(4):342-350
Dependence of the diurnal periodicity phase diagrams for Southern California earthquakes on their magnitude is studied with the Rayleigh-Schuster method. The highest statistical significance of diurnal periodicity is characteristic for the weakest non-representative earthquakes occurring in the night rather than in the daytime. The statistical significance of the earthquake diurnal periodicity decreases as the earthquake magnitude increases. Diurnal periodicity disappears in the neighborhood of the catalog magnitude of completeness. It appears again with a reasonably high level of statistical significance in the magnitude range exceeding the magnitude of completeness. However, its phase becomes opposite: strong earthquakes are more frequent in the daytime. Phase diagrams of different spatial earthquake sample groups are compared, and the night and daytime earthquake recurrence graphs are studied. 相似文献
19.
Analysis of the spatial distribution between successive earthquakes occurred in various regions in the world 总被引：1，自引：1，他引：0
Elisaveta Marekova 《Acta Geophysica》2014,62(6):1262-1282
The earthquake spatial distribution is being studied, using earthquake catalogs from different seismic regions (California, Canada, Central Asia, Greece, and Japan). The quality of the available catalogs, taking into account the completeness of the magnitude, is examined. Based on the analysis of the catalogs, it was determined that the probability densities of the inter-event distance distribution collapse into single distribution when the data is rescaled. The collapse of the data provides a clear illustration of earthquake-occurrence self-similarity in space. 相似文献
20.
Application of fuzzy clustering method to determining sub-fault planes of earthquake from aftershocks sequence 
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下载免费PDF全文 Earthquake rupture process generally involves several faults activities instead of a single fault. A new method using both fuzzy clustering and principal component analysis makes it possible to reconstruct three dimensional structure of involved faults in earthquake if the aftershocks around the active fault planes distribute uniformly. When seismic events are given, the optimal faults structures can be determined by our new method. Each of sub-fault planes is fully characterized by its central location, length, width, strike and dip. The resolution determines the number of fault segments needed to describe the earthquake catalog. The higher the resolution, the finer the structure of the reconstructed fault segments. The new method successfully reconstructs the fault segments using synthetic earthquake catalogs. By taking the 28 June 1992 Landers earthquake occured in southern California as an example, the reconstructed fault segments are consistent with the faults already known on geological maps or blind faults that appeared quite frequently in longer-term catalogs. 相似文献