New data on the geological structure of the junction of the Cape Verde Rise, Cape Verde Abyssal Basin, and Bathymetrists Seamounts (Central Atlantic Ocean)     

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

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The model Re-Os age of platinum group minerals from Vilyui placers in the eastern Siberian Craton     

A. V. Okrugin  A. I. Kostoyanov  S. S. Shevchenko  V. G. Lazarenkov 《Doklady Earth Sciences》2006,410(1):1044-1047

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Unusual types of degassing from melts of peripheral magma chambers of “dormant” El’brus volcano, Russia: Geochemical and mineralogical features     

A. G. Gubanov  O. A. Bogatikov  B. S. Karamurzov  L. E. Tsukanova  A. B. Leksin  V. M. Gazeev  A. V. Mokhov  T. A. Gornostaeva  A. V. Zharikov  V. M. Shmonov  A. Ya. Dokuchaev  S. A. Gorbacheva  A. V. Shevchenko 《Journal of Volcanology and Seismology》2011,5(4):223-240

In addition to traditional degassing of the melt in the subsurface magma chambers of the “dormant” El’brus volcano, alsodegassing through pores and microcracks that occur in the top of magma chambers has also been detected. It is proven by studies of compactness, porosity, and permeability of the rocks. The speeds at which gases (H, He, H₂S, CO₂, F, and Cl) pass through gneiss and volcanic rocks were estimated. Magma chambers on the ground surface are expressed in stable thermal anomalies revealed by night-time thermal sounding from an NOAA satellite. The presence of magma chambers at depths of 2–12 km was proven by magnetotelluric sounding [Sobisevich et al., 2003] and gravity studies. In addition to occasional “columns” of bright-white fluorescence above the thermal anomalies, aerosol “clouds” and hydrogen flows were detected by lidar and hydrogen surveying [Alekseev et al., 2007, 2009]. Observation at the same sites detected steam outbursts occurring periodically, the snow-ice cover thaws and the smell of hydrogen sulfide is felt. Geochemical characteristics of degassing were studied by snow sampling from up to 1 m deep pits. They were taken within contours of the thermal anomalies, above active fault zones, in the sites of bright-white fluorescence “columns,” and on a new fumarole locality. It is shown that the degassing of melt was accompanied by the gas transporting many elements (Li, B, Si, P, S, Ca, Zn, Pb, Mo, Ba, W, Hg, Ag, U, Th, I, Au, and Pt) in a fine-grained state (a few microns or possibly nanometers) with an active participation of F and Cl. Native platinum, chalcopyrite, halite, sylvite, barite, gypsum, zircon, opal, chlorinated organics, etc. were for the first time discovered in the Mt. El’brus area using electron microscope studies of solid residue from dehydrated snow samples. “Hidden” ore mineralization genetically related to degassing of melts enriched in ore elements may be supposedly found in paleo- and present-day areas of volcanic activity.  相似文献   

Petropavlovsk base seismic station for the tsunami warning service     

V. N. Chebrov  D. V. Droznin  N. Z. Zakharchenko  V. N. Mishatkin  V. A. Sergeyev  V. A. Sinitsyn  Yu. V. Shevchenko 《Seismic Instruments》2011,47(1):1-7

Hardware and software are developed for the first base seismic station in the modernized seismic subsystem for tsunami warning on Kamchatka. The station is formed as a seismic array. The structure of the equipment and its communication systems are described. The station is introduced into experimental operation. The first results of recording of a local strong earthquake at points of the Petropavlovsk station are discussed.  相似文献   

Tsunami Measurements in Bays of Shikotan Island     

Georgy Shevchenko  Alexander Shishkin  Grigory Bogdanov  Artem Loskutov 《Pure and Applied Geophysics》2011,168(11):2011-2021

Bottom pressure gauges deployed in bays of Shikotan Island (South Kuril Islands) recently recorded two tsunamis: the Simushir (Kuril Islands) tsunami of January 13, 2007 generated by a local earthquake with magnitude M _w = 8.1 and the Peruvian tsunami of August 15, 2007 generated by a distant earthquake, M _w = 8.0. The records enabled us to investigate the properties of these two tsunamis and to estimate the effect of the regional and nearshore topography on arriving tsunami waves. Eigen periods and spatial structure of resonant oscillations in particular bays were examined based on results of numerical modeling. Significant amplification of the fundamental (Helmholtz) resonant modes in Malokurilskaya Bay (19 min) and in Krabovaya Inlet (29 min) and some secondary modes was caused by the Simushir tsunami. The considerably different geometry and bottom topography of these bays, located on the inner coast of the island, determine the differences in their eigen periods; the only mutual peak, which was found in both basins, had a period of 5 min and was probably related to the source features. The Peruvian tsunami was clearly recorded by the bottom pressure gauge in Tserkovnaya Bay on the outer (oceanic) coast of the island. Three dominant periods in the tsunami spectrum at this bay were 60, 30 and 19 min; the latter period was found to be related to the fundamental mode of the bay, while the other two periods appear to be associated with the shelf resonant amplification of tsunami waves arriving in the region of the South Kuril Islands. The prevalence of low-frequency components in the observed tsunami spectrum is probably associated with the large extension of the initial source area and faster decay of short period waves during the long trans-oceanic tsunami propagation.  相似文献   

New data about tsunami evidence on Russia’s Pacific coast based on instrumental measurements for 2009–2010     

Shevchenko  G. V.  Ivel’skaya  T. N.  Kovalev  P. D.  Kovalev  D. P.  Kurkin  A. A.  Levin  B. V.  Likhacheva  O. N.  Chernov  A. G.  Shishkin  A. A. 《Doklady Earth Sciences》2011,438(2):893-898

Doklady Earth Sciences -  相似文献   

The junction of the eastern Central Asian Fold Belt and the Siberian Platform: deep structure and Mesozoic tectonics and geodynamics     

B.F. Shevchenko  M.V. Goroshko  A.N. Didenko  V.A. Gur'yanov  V.S. Starosel'tsev  A.S. Sal'nikov 《Russian Geology and Geophysics》2011,52(12):1672-1679

The tectonic structure of the junction of the eastern Central Asian Fold Belt and the Siberian Platform, along with the deep structure of the Earth's crust and lithosphere in this region, has been described on the basis of new geological and geophysical data (seismic, geoelectric, and space-structural studies as well as new-generation geological maps), combined with new interpretation techniques (processing of the previous data by special software). The data suggest the existence of oblique collision during the convergence of the tectonic plates and, correspondingly, tectonic units composing these plates, when the Mongol–Okhotsk paleobasin closed. Such a scenario within the Aldan–Stanovoi Shield is evidenced by areas of syn- and postcollisional magmatism, with their deep-level and geochemical characteristics, and by the presence of a Late Mesozoic fold–thrust zone. Deep “traces” of these tectonomagmatic events, detected in the course of geological and geophysical modeling, are manifested in inclined deep boundaries between the crustal and lithospheric blocks. On the Earth's surface, they correspond to large fault systems: the Dzheltulak, North and South Tukuringra, Gulyui, and Stanovoi. It has been found that the influence of collision decreases northward with distance from the junction of the eastern Central Asian Fold Belt and the Siberian Platform (Dzheltulak and North Tukuringra transcrustal faults).  相似文献   

The inhabitants of the spring ice,under-ice water,and sediments of the white sea in the estuarine zone of the Severnaya Dvina River     

A. F. Sazhin  F. V. Sapozhnikov  T. N. Rat’kova  N. D. Romanova  V. P. Shevchenko  A. S. Filippov 《Oceanology》2011,51(2):295-305

The data on the supra-ice snow, ice, under-ice water, and benthic algal flora obtained in 2007–2008 by sampling in the estuary of the Severnaya Dvina River are analyzed. The river ice and under-ice water in the estuarine zone and in the channel part of the Severnaya Dvina differed greatly in the algal flora’s composition. The fresh water species never exceeded 8.6%, while the ice algae composed 90–96% of the total ice inhabitants’ biomass. In the under-ice water, this value did not exceed 58–64%. The bacteria in the ice composed not more than 2.5–10% of the total biomass, while, in the under-ice water, 36–49%. The shares of ciliates (0.04%) and nematodes (0.005–1.6%) in the total biomass were negligible. In the estuarine zone, the ice was inhabited mainly by nematodes (78% of the total biomass), while, in the river, their share decreased to 9%. The contribution of bacteria was 15% in Dvina Bay and increased to 61% in the river. The importance of algae in the snow was minor: 7% of the total biomass in the marine zone and 30% in the river region. High species diversity of the algal flora in the sandy and sandy-silty littoral grounds was revealed. The values of the total biomass of the bottom algal flora (0.38 g C/m²) were only two to three times lower than the values revealed in similar habitats in the summer. The epipelithic forms (0.15 g C/m²) dominated, being represented by 46 species of algae (49%). The shares of epipsammonic (0.12 g C/m²) and planktonic (0.11 g C/m²) species were almost equal to each other: 25 and 22 species, respectively (27 and 24%).  相似文献   

Studies of the White Sea System from onboard the R/V Ekolog in July 2010     

V. P. Shevchenko  R. A. Ananyev  A. I. Gusakova  N. N. Dmitrevskii  M. D. Kravchishina  A. V. Mishin  N. V. Politova  M. S. Potakhin  A. V. Tolstikov  A. S. Filippov  A. L. Chul’tsova 《Oceanology》2011,51(6):1074-1077

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Mechanochemical processing of low-grade diamond into nanocomposite materials     

F. Kh. Urakaev  V. S. Shevchenko  A. M. Logvinova  I. A. Madyukov  E. I. Petrushin  T. S. Yusupov  N. V. Sobolev 《Doklady Earth Sciences》2007,415(1):755-758

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