Remarks on seismic energy release related to strike slip and tensile crack mechanisms     

Jan Kozák  Jan Šílený  Aleš Špičák  Reviewer V. Červený 《Studia Geophysica et Geodaetica》1984,28(2):156-163

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Earthquake     

Jan Kozák  Reviewer A. Zátopek 《Studia Geophysica et Geodaetica》1985,29(1):100-100

Summary Original copper engraving depicting an earthquake is reproduced and discussed.  相似文献   

Recent structures and tectonic regimes of the stress–strain state of the Earth’s crust in the northeastern sector of the Russian Arctic region     

L. P. Imaeva  V. S. Imaev  V. I. Mel’nikova  B. M. Koz’min 《Geotectonics》2016,50(6):535-552

A comprehensive investigation aimed at determining seismotectonic types of destruction and the stress–strain state of the Earth’s crust in the main seismogenerating structures of the Arctic–Asian seismic belt is conducted for the territory of the northeastern sector of the Russian Arctic region. Based on the degree of activity of geodynamical processes, the regional principles for ranking neotectonic structures are elaborated, and neotectonic zoning is carried out based on the substantiated differentiation of the corresponding classes. Within the limits of the Laptev Sea, Kharaulakh, and Lena-Anabar segments, we analyzed I the structural–tectonic position of the most recent structures, II the deep structure parameters, III the parameters of the active fault system, and IV the parameters of the tectonic stress field, as revealed from tectonophysical analysis of Late Cenozoic fault and fold deformations. Based on the seismological data, the mean seismotectonic deformation tensors are calculated to determine, in combination with geological and geophysical data, the orientations of the principal stress axes and to reveal the structural–tectonic regularity for tectonic regimes of the stress–strain state of the Earth’s crust in the Arctic sector of the boundary between the Eurasian and North American lithospheric plates.  相似文献   

Nonlinear processes in earthquake foci     

V. Aksenov  J. Kozák  T. Lokajíček 《Pure and Applied Geophysics》1993,140(1):29-47

The results of laboratory experiments on biaxially compressed physical models of a seismic source are presented, discussed and interpreted in terms of nonlinear dynamics; the relation is shown between the degree of seismic pulse coherency (expressed through the amplitude frequency spectra development) and energy (or magnitude) in a series of model experiments. It has been ascertained that the degree of radiated waves coherency plays a more important role concerning the seismic energy release than the size (radius) of the seismic source.The relations among individual source parameters obtained in the laboratory were tested by the analysis of three series of seismograms of aftershocks which followed the 1988 Spitak earthquake (two series) and the 1975 Oroville earthquake (one series). The fundamental effect observed in the laboratory, i.e., the growth of pulse coherency with increasing stress concentration in the focal region (reflected in growing earthquake magnitude), was clearly manifested in all three earthquake aftershock series.Due to derivation by a comparison of the above results, obtained on the basis of nonlinear dynamics with the classical source models by Brune, Madariaga and others, it seems to be namely the self-organizing of the structure itself caused by the increasing stress field in the seismic source, which can answer the question concerning the degree of energy cumulation in the earthquake focus at a given moment.  相似文献   

First macroseismic map in transalpine Europe (1810 Mór earthquake in the Pannonian Basin)     

Jan Kozák  Ivan Prachař 《Studia Geophysica et Geodaetica》2010,54(2):339-341

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Seismotectonic analysis of the Yana-Indigirka segment of the Chersky zone     

L. P. Imaeva  V. S. Imaev  B. M. Koz’min 《Izvestiya Physics of the Solid Earth》2011,47(12):1045-1057

Kinematic types of seismogenerating structures, morphotectonic features of the present-day topography, and the corresponding tectonic stress fields derived from the focal mechanisms of local earthquake and the types of Late Cenozoic folding and faulting are analyzed to create a model of current geodynamics in the Yana-Indigirka segment of the Chersky seismotectonic zone. The kinematic environment in the Yana-Indigirka segment of the Chersky seismotectonic zone is a result of the interaction of conjugate differently oriented strike-slip displacements under transpression conditions (a compression with strike-slip). It is possible to reconstruct these conditions, if we assume that the Kolyma-Omolon block (superterrain) located in the frontal part of the North American Plate played the role of an active indenter during the approach of the North American and Eurasian Plates.  相似文献   

Analysis of geologic reference materials for REE and HFSE by inductively coupled plasma-mass spectrometry (ICP-MS)   总被引：1，自引：0，他引：1  

I. V. Nikolaeva  S. V. Palesskii  O. A. Koz’menko  G. N. Anoshin 《Geochemistry International》2008,46(10):1016-1022

A variant of the ICP-MS technique was developed for the analysis of geological materials for REE and HFSE (Zr, Nb, Hf, and Ta) and is illustrated by analyzing geological reference materials (GRM) of various composition. The chemical preparation of the samples, including their sintering/fusing with highly purified Li metaborate and the stabilization of the solution, ensures the complete transfer of the elements to be analyzed into solution. The use of an ELEMENT high-sensitivity mass spectrometer with an U-5000AT+ ultrasonic nebulizer made it possible to improve the detection limits of REE and HFSE. A combination of an external calibration with internal standard for the calculation of the concentrations allowed us to take into account the effect of the matrix and variations in the plasma parameters on the analytical signal. The accuracy of the method is illustrated by the comparison of the results obtained on the most reliably certified GRM with the values assumed for them. The relative standard deviation of the analysis amounts to 2–5% on average, depending on the concentrations.  相似文献   

Analysis of spatial distribution of mining tremors occurring in Rudna copper mine (Poland)   总被引：1，自引：0，他引：1  

Maria Kozłowska 《Acta Geophysica》2013,61(5):1156-1169

The distribution of mining tremors is strictly related to the exploitation progress of mining works and, consequently, to the local stress field. In case the distribution is known, it is possible to determine future area of intensive seismicity in exploited mining panel. In the paper, an analysis of working face-to-tremor distance for Rudna copper mine in Poland is presented. In order to develop a spatial model of tremors’ occurrence in the exploited mine, the seismicity of four mining sections in the five-month period was investigated and the tremors’ distribution was obtained. It was compared with the spatial distribution of tremors in coal mines found in the literature. The results show that the places where tremors mostly occur — the vicinity of the face, in front of it — coincide with the high-stress area predicted by literature models. The obtained results help to predict the future seismic zone connected with planned mining section, which can be used in seismic hazard analysis.  相似文献   

San Francisco earthquake of April 18th, 1906, a hundred-year anniversary of disastrous Californian event     

J. T. Kozák 《Studia Geophysica et Geodaetica》2006,50(2):319-321

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Dynamics of seismogenerating structures in the frontal zone of the Kolyma–Omolon superterrane     

L. P. Imaeva  V. S. Imaev  B. M. Koz’min 《Geotectonics》2016,50(4):349-365

To develop a model for the dynamics of seismogenerating structures in the frontal zone of the Kolyma–Omolon superterrane (Chersky seismotectonic zone), the following aspects are analyzed: structural–tectonic position, deep structure parameters, active faults, and fields of tectonic stresses as revealed from solutions of focal mechanisms of strong earthquakes and kinematic types of Late Cenozoic fold deformations and faults. It is found that a certain dynamic setting under transpressional conditions takes place and it was caused by the interaction between structures of the Eurasian, North American, and Okhotsk lithospheric plates within regional segments of the Chersky zone (Yana–Indigirka and Indigirka–Kolyma). These conditions are possible if the Kolyma–Omolon block located in the frontal zone of the North American Plate was an indenter. Due to this, some terranes of different geodynamic origin underwent horizontal shortening, under which particular blocks of segments were pushed out laterally along the orogenic belt, on a system of conjugated strike-slip faults of different directions and hierarchical series, in the northwest and southeast directions, respectively, to form the main seismogenerating reverse-fault and thrust structures with the maximum seismic potential (M ≥ 6.5).  相似文献