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991.
Changes in the directionality of surface high-frequency geoacoustic emission during periods of deformational disturbances
on the diurnal time scale prior to strong seismic events on Kamchatka have been investigated. It has been shown that while
the emission intensity grows by over an order of magnitude, sharp maxima appear in the direction of longitudinal acoustic
oscillations. Based on their position, the orientation of the major compression axis can be determined, whose chaotic motion
exhibits two metastable states around the direction to the epicenter of the earthquake. 相似文献
992.
993.
994.
995.
Polyakov A. S. Roslyakov A. G. Lobkovskii L. I. Levchenko O. V. Putans V. A. Ambrosimov A. K. Merklin L. R. Anan’ev R. A. Dmitrevskii N. N. Libina N. V. 《Doklady Earth Sciences》2010,431(1):376-379
By means of mathematical modeling, the parameters of flows forming sedimentary waves on the western slope of the Derbent basin
were estimated. The height of these flows depends on the slope steepness and varies from 25 to 170 m to reach its maximum
values at gentler slope areas. However, the flow rate is independent of the slope steepness and depends only on the concentration
of sediment matter supplied by the flow. At the upper part of the slope (the flow starting), the rate amounts to 0.4–1.4 m/s,
being almost halved at the depths where the sedimentary waves are damped. The present rates of near-bottom currents show pronounced
seasonal differences, and their values are close to flow rates obtained by numerical modeling. 相似文献
996.
997.
A. F. Morozov B. N. Khakhaev O. V. Petrov V. I. Gorbachev G. V. Tarkhanov L. D. Tsvetkov Yu. M. Erinchek A. M. Akhmedov V. A. Krupenik K. Yu. Sveshnikova 《Doklady Earth Sciences》2010,435(1):1483-1486
A thick (200 m) rock salt mass covering Late Archean granitoids was exposed for the first time in the Early Proterozoic volcanogenic-sedimentary
formations in the Onega trough of the east Baltic Shield by the Onega parametric well. The mineral composition of salts, their
geochemical features, and the isotopic composition of carbonate carbon and oxygen have been studied. After fluid inclusions
present in salts, their metamorphism temperature and isotopic composition of helium and argon were determined. The obtained
results give evidence of the fact that rock salts and magnesites associated with them were formed in an evaporate basin with
participation of deep crustal processes. The age of the underlying granitoids (2.716 ± 9 Ma) is determined using the Pb—Pb
method. 相似文献
998.
Doklady Earth Sciences - 相似文献
999.
1000.
O. P. Polyansky S. N. Korobeynikov V. G. Sverdlova A. V. Babichev V. V. Reverdatto 《Doklady Earth Sciences》2010,430(2):158-162
Computer simulation of subduction was performed using nonlinear equations of deformable solid mechanics encompassing all types
of nonlinearity: geometric, physical, and contact. This study presents a numerical model of subduction with allowance for
the gabbro-to-eclogite phase transition. The model rheology is a plastic compressible material (Mohr-Coulomb law for a deformed
rock material). It was shown that deep subduction can be modeled well with the selection of appropriate parameters of rock
plasticity providing the initial thickening in the subducting slab nose. 相似文献