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11.
This paper presents an integrated measurement technique based on DC methods (vertical electrical sounding, electrical resistivity tomography) which was used to identify faults and determine their geoelectric parameters in the western part of the Chuya basin. New information on the structure of the Chagan River valley located in the zone of the disastrous 27 September 2003 Chuya earthquake has been obtained from the results of these methods. Geoelectric cross-sections of the sedimentary sequence and the upper part of the basement were obtained from VES data, showing the block structure of the study area. Electrical resistivity tomography sections confirm the presence of a major fault between basement blocks of different heights and indicate the presence of faults bounding the valley on its right side and in the southwestern part. 相似文献
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G. A. Sobolev A. V. Ponomarev Yu. Ya. Maibuk 《Izvestiya Physics of the Solid Earth》2016,52(5):674-691
A series of laboratory experiments have been carried out with a model of two granite blocks under biaxial compression loading. The experiments are mainly intended for assessing the possibilities of partially releasing the accumulated potential energy. The model was subjected to calibrated mechanical impacts (strokes) which induced elastic impulses. The mechanical stresses, strains, and acoustic emission were recorded. The strokes caused both large slips releasing the stresses down to their initial level and small slips which reduced the stresses by 5–8%. The small slips mostly occurred after the precursory emergence of the low frequency oscillations having low amplitudes. Before the large slips, the stages of speeding-up of the relative motion of the sides of the block contact was observed, similar to those emerging before the natural slips unrelated to the strokes. This feature was not universal: in some cases, the model recovered to the stationary state of the block contact without a large slip. All the slips occurred with a time delay after the stroke. The time delay was shorter when the energy of the blow was higher. With the shorter time delays, the small slip is more likely to occur. The energy of the impacts was by three orders of magnitude lower than the energy accumulated by the model, which points to the triggering mechanism of slip initiation. The series of strokes resulting in the small displacements partially reduced the accumulated energy and prevented the emergence of large motions such as the stick-slip events. If after a series of such blows a large sliding event still occurred, its energy was higher than in the slips unrelated to the impacts. The experiments revealed the difficulties in solving the problem of earthquake hazard reduction by elastic impacts. 相似文献
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Acoustic signals arising due to the contacting-breaking of reed switches are analyzed. They are compared with other acoustic signal sources. Recommendations for using reed switches as a source of calibrated signals in laboratory experiments on hard material samples are given. 相似文献
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K. S. Ivanov Yu. N. Fedorov V. S. Ponomarev V. A. Koroteev Yu. V. Erokhin 《Doklady Earth Sciences》2012,443(1):321-325
The SHRIMP-II zircon U-Pb dates for metamorphic rocks from the West Siberian basement are determined for the first time. It
is established that the major protolith of the metamorphic strata from the Shaimsk-Kuznetsovsk meganticlinorium is composed
of sedimentary Late- and Middle-Devonian rocks (395–398 Ma). It is likely that the greywackes, whose strata were mainly formed
under erosion of ophiolitic rocks, served as a substrate for the metamorphic rocks. The metamorphic transformations of the
rocks occurred under conditions of greenschist and occasionally lower amphibolite facies of metamorphism during the Late Carboniferous-Early
Permian period. 相似文献
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We have estimated the variations in the atmospheric electrostatic field (AEF, E
Z(0)) strength in the surface layer caused by variations in conductivity due to radon influences, cosmic ray intensity, changes
in the balance of light and heavy ions during sunset and sunrise, and under the effect of the ionospheric electric current
potential on the AEF potential. It is shown that the air conductivity varies due to ionization under the effect of radon emanations
and is determined by the radon exhalation and turbulent diffusion of the surface air layer, while the cosmic ray intensity
affects the surface air conductivity through changes in the ion recombination conditions. A decrease in the air conductivity
due to a decrease in the cosmic ray intensity (Forbush decrease) also decreases E
Z(0), while a decrease in radon fluxes results in an increase in E
Z(0). We have estimated the effect of illumination conditions on the AEF due to variations in the relative concentration of heavy
and light ions under the influence of photodetachment and photoattachment processes. The work has been done on the basis of
data received from the Paratunka observatory (Kamchatka). 相似文献
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G. A. Sobolev A. V. Ponomarev A. V. Koltsov V. B. Smirnov 《Pure and Applied Geophysics》1996,147(2):345-355
The experiments were conducted for the study of stick-slip at the contact between two granite blocks. Three cases were studied under the following conditions: 1) the increase of load at a constant rate; 2) the additional application of sinusoidal oscillations in the frequency range from 1 to 30 Hz; 3) subjection to the impulse in the kilohertz frequency range. The imposition of sinusoidal oscillations with the amplitude of 15% of the maximal load caused the reduction of time by 10% for the discussed in terms of durability. The high frequency impulse influence increased this effect and also caused essential changes in the amplitude of elastic oscillations generating during the stick-slip. The trigger phenomena should be integrated in prediction models of the time and magnitude of earthquakes. 相似文献
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D. A. Lockner J. D. Byerlee V. S. Kuksenko A. V. Ponomarev 《Pure and Applied Geophysics》1986,124(3):601-608
Measurements of charge separation in rock during stable and unstable deformation give unexpectedly large decay times of 50 sec. Time-domain induced polarization experiments on wet and dry rocks give similar decay times and suggest that the same decay mechanisms operate in the induced polarization response as in the relaxation of charge generated by mechanical deformation. These large decay times are attributed to electrochemical processes in the rocks, and they require low-frequency relative permittivity to be very large, in excess of 105. One consequence of large permittivity, and therefore long decay times, is that a significant portion of any electrical charge generated during an earthquake can persist for tens or hundreds of seconds. As a result, electrical disturbances associated with earthquakes should be observable for these lengths of time rather than for the milliseconds previously suggested. 相似文献
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S. G. Skolotnev N. N. Turko S. Yu. Sokolov A. A. Peyve N. V. Tsukanov S. Yu. Kolodyazhnyi N. P. Chamov Yu. E. Baramykov A. S. Ponomarev V. N. Efimov A. E. Eskin V. V. Petrova L. A. Golovina V. Yu. Lavrushin E. A. Letyagina E. P. Shevchenko K. V. Krivosheya L. V. Zotov 《Doklady Earth Sciences》2007,416(1):1037-1041