Physical causes of diurnal variations in the geoacoustic emission level     

V. A. Gavrilov 《Doklady Earth Sciences》2007,414(1):638-641

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Numerical modeling of the propagation of nonlinear acoustic-gravity waves in the middle and upper atmosphere     

N. M. Gavrilov  S. P. Kshevetskii 《Izvestiya Atmospheric and Oceanic Physics》2014,50(1):66-72

A numerical algorithm for modeling the vertical propagation and breaking of nonlinear acoustic-gravity waves (AGWs) from the Earth’s surface to the upper atmosphere is described in brief. Monochromatic variations in the vertical velocity at the Earth’s surface are used as an AGW source in the model. The algorithm for solving atmospheric hydrodynamic equations is based on three-dimensional finite-difference analogues of fundamental conservation laws. This approach selects physically correct generalized solutions to hydrodynamic equations. A numerical simulation is carried out in an altitude region from the Earth’s surface to 500 km. Vertical profiles of the background temperature, density, and coefficients of molecular viscosity and heat conduction are taken from the standard atmosphere models. Calculations are made for different amplitudes of lower-boundary wave forcing. The AGW amplitudes increase with altitude, and waves may break in the middle and upper atmosphere.  相似文献   

Results from field and stationary tests of the seismic signal recorder Delta 03     

A. V. Gavrilov  A. V. Konovalov  S. P. Nikiforov 《Seismic Instruments》2011,47(3):271-277

The operation of a new domestic seismic signal recorder Delta 03 is analyzed. The optimization of technical requirements on parameters of the recorder, the test cycle, adjustment in the process of testing individual technical solutions, and improvement of the device were carried out in close cooperation with its designers from OOO Logic Systems (Ramenskoye, Moscow Region). At the time of writing, the recorder Delta 03 is a robust device that is recommended for use in seismic monitoring systems of various levels.  相似文献   

Comparison of the geoacoustic measurements in boreholes with the data of laboratory and in-situ experiments on electromagnetic excitation of rocks     

V. A. Gavrilov  L. M. Bogomolov  A. S. Zakupin 《Izvestiya Physics of the Solid Earth》2011,47(11):1009-1019

The data of borehole geoacoustic and electromagnetic measurements in Kamchatka are compared with the results of laboratory and field experiments on electromagnetic excitation of rocks. A noticeable similarity in the responses of the natural geological medium and rock specimens is observed. The field experiments with controlled electromagnetic sources show that the geophones placed in boreholes are capable of reliably detecting the responses of rocks in situ to electric impacts as low as 0.5 mV/m. The obtained results provide the experimental evidence in favor of the previously proposed hypothesis of modulation of geoacoustic emission in rocks in situ by the ULF atmospheric electromagnetic field.  相似文献   

Lithological and Geochemical Characteristics of the Paleocene/Eocene Sediments corresponding to the PETM Biospheric Event in the Eastern Crimea (Nasypnoe Section)     

Yu. O. Gavrilov  O. V. Golovanova  E. V. Shchepetova  B. G. Pokrovsky 《Lithology and Mineral Resources》2018,53(5):337-348

The paper reports lithological and geochemical data on the stratigraphic interval corresponding to the Paleocene/Eocene Thermal Maximum (PETM) event in the Paleogene section of Eastern Crimea (Nasypnoe section). The section is located on the western continuation of the sublatitudinal profile consisting of 15 PETM sections spanning the area from Crimea to Tajikistan (over 2500 km). It is shown that PETM sediments have the negative δ¹³C and δ¹⁸O isotope excursions and are enriched in kaolinite, which is typical of most sections of this interval around the world. At the same time, the extremely low content of organic matter (OM) in sediments of the Nasypnoe section makes them sharply different from the highly carbonaceous rocks of the PETM interval in Central and Eastern Caucasus, and Central Asian regions. This is correlated with the low contents of many chemical elements in the studied rocks, and their extremely high contents in the highly carbonaceous rocks of the easterly sections. Thus, Eastern Crimea in the end of the Paleocene?beginning of the Eocene was occupied by the low-bioproductive marine paleobasin, whereas the coeval paleobasin in Central Asia was characterized by extremely high bioproductivity owing to the presence of significant amount of phosphorus.  相似文献   

Peculiarities of approximation of meteorological characteristics having vertical gradient discontinuities close to the tropopause     

N. M. Gavrilov 《Russian Meteorology and Hydrology》2013,38(6):382-386

Carried out is an analysis of errors of different approximation methods for separating the long- and short-wave parts of the spectra of the vertical distribution of meteorological variables and gas components in the areas of dramatic variations of their vertical gradients close to the tropopause. Proposed is an integrated approach using the polynomial, piecewise-linear, and spectral filtration and enabling to minimize the errors of approximation of long- and short-wave components of profiles of meteorological characteristics in the troposphere and stratosphere including the tropopause area. The method is useful for analyzing the mean values and mesoscale variations of meteorological parameters measured by the modern balloon and satellite systems.  相似文献   

Geochemistry of native gold from deposits of various types   总被引：1，自引：0，他引：1  

L. A. Nikolaeva  A. N. Nekrasova  S. A. Milyaev  S. V. Yablokova  A. M. Gavrilov 《Geology of Ore Deposits》2013,55(3):176-184

The ICP-MS-analyzed 490 samples of lode and placer gold allowed us to detect a wide spectrum of trace elements in native gold from the most abundant gold-polysulfide-quartz, low-sulfide gold-quartz, and gold-silver deposits from various gold provinces and districts of the Russian Federation. The typical set of elements in gold of each deposit type has been determined. The distribution of REE, rare alkali and alkaline earth metals in native gold is estimated for the first time, and a geochemical index has been proposed to typify gold occurrences. Compositional differences of native gold are also caused by regional metallogenic features of gold provinces. The results obtained make it possible to determine a type of lode and placer gold occurrences at early stages of geological exploration.  相似文献   

Cross-correlation earthquake precursors in the hydrogeochemical and geoacoustic signals for the Kamchatka peninsula     

Gennadiy V. Ryabinin  Valeriy A. Gavrilov  Yuriy S. Polyakov  Serge F. Timashev 《Acta Geophysica》2012,60(3):874-893

We propose a new type of earthquake precursor based on the analysis of correlation dynamics between geophysical signals of different nature. The precursor is found using a two-parameter cross-correlation function introduced within the framework of flicker-noise spectroscopy, a general statistical physics approach to the analysis of time series. We consider an example of cross-correlation analysis for water salinity time series, an integral characteristic of the chemical composition of groundwater, and geoacoustic emissions recorded at the G-1 borehole on the Kamchatka peninsula in the time frame from 2001 to 2003, which is characterized by a sequence of three groups of significant seismic events. We found that cross-correlation precursors took place 27, 31, and 35 days ahead of the strongest earthquakes for each group of seismic events, respectively. At the same time, precursory anomalies in the signals themselves were observed only in the geoacoustic emissions for one group of earthquakes.  相似文献   

Convection model of post-glacial uplift     

S. V. Gavrilov 《Izvestiya Physics of the Solid Earth》2009,45(5):437-443

A new approach to analytical and numerical study of the process of the post-glacial uplifting of the Earth’s surface was proposed within the framework of a viscous model. Displacement of the Earth’s surface is considered as the motion of the density boundary due to chemico-density convection. It is shown that the incorporation of the non-Newtonian rheology at observed velocities of post-glacial uplifts requires an obligatory presence of faults in the lithosphere and gives rise to quasi-uniform motion of the mantle material, whose viscosity under the lithosphere is, on the average, sufficiently small and amounts to ～10¹⁹ Pa. The study of the stability of the constructed model of the post-glacial uplift considered as the chemico-density convection relative to the thermal convection shows that the velocity of thermal convection developing in the presence of a quasiuniform mantle flow related to the post-glacial recovery is ～1 m/yr.  相似文献   

New architecture of an automated system for acquisition,storage, and processing of seismic data     

A. A. Stepnov  A. V. Gavrilov  A. V. Konovalov  L. Ottemöller 《Seismic Instruments》2014,50(1):67-74

Features of the new architecture of an automated system for acquisition, storage, and processing of seismic data are considered in detail. The system is based on SEISNET and SEISAN software. Specific technologies, software, and examples of the interconnection of system components are presented. The functionality of the system and the data life cycle are shown. An example of the implementation of the new architecture in the existing seismic monitoring network in the northern part of Sakhalin Island is examined.  相似文献