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R. Yu. Tarakanov E. G. Morozov A. M. Gritsenko T. A. Demidova N. I. Makarenko 《Oceanology》2013,53(4):432-441
The structure of northerly overflow of Antarctic Bottom Water (AABW) through passages in the East Azores Ridge (37° N) in the East Atlantic from the Madeira Basin to the Iberian Basin is studied on the basis of hydrographic measurements carried out by the Institute of Oceanology, Russian Academy of Sciences (RAS) in October 2011, historical World Ocean Data Base 2009, and recent data on the bottom topography. The overflow of the coldest layers of this water occurs through two passages with close depths at 16° W (Discovery Gap) and at 19°30′ W (nameless Western Gap). It is shown that it is likely that the role of the latter passage in water transport was underestimated in earlier publications because the water (2.01°C) found in the region north of the Western Gap was cooler than in the region north of the Discovery Gap (2.03°C). In 2011, we found a decrease of 0.01°C in the AABW temperature near the bottom compared to previous measurements in 1982 (from 2.011°C to 2.002°C). Analysis of the historical database shows that this decrease is most likely caused by the cooling trend in the abyssal waters in the East Atlantic basins. 相似文献
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Spatial pattern analysis of marine terrace elevations from 40–30 thous. years BP was used to reconstruct sea level/geoid surface
and geoid parameters during that time. The polar flattening of geodetic ellipsoid was lower than its present value (1/298.81
and 1/298.26) respectively because of glacial-induced mass redistribution. Increase in polar stress occurred during the last
30 thous. years was possibly driven by pertubation brought to the gravitational field by disintegration of polar ice sheets
in the Northern hemisphere. But the polar flattening value becomes only half-restored during the last deglacial hemicycle.
So repetitive glacial advances during Pleistocene acted as a global “pump” for uncondensed zones at the upper/lower mantle
boundary. Dissipation of tidal energy is an order of magnitude less intensive in its Earth's rotation effect.
A contribution to the International Geological Correlation Programme Project JGCP — 274 “Coastal Evolution in the Quaternary”. 相似文献
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R. Z. Tarakanov 《Journal of Volcanology and Seismology》2008,2(6):411-423
According to S.A. Fedotov’s long-term earthquake forecast, the Middle Kuril Is. has long (since 1965) been a likely location for the next M ≥ 7.7 earthquake, i.e., a seismic gap. The present study integrates seismological, geological, and geophysical data to assess the earthquake potential of the gap prior to November 15, 2006. Seismological data were used to carry out a comparative analysis of 3D seismic energy density for three zones of the Kuril region. The density for the Middle Kuril Is. turned out to be twice as small as that for the North Kuril Is. and nearly six times as small as that for the South Kurils. Various parameters of the seismic process for the Kuril region have been estimated in quantitative terms. It is shown that the rate of completely reported (M ≥ 6) earthquakes occurring down to 70 km depth in the Middle Kuril Is. is approximately three times as small as that for the entire Kuril arc. Increased heat flow was recorded there (up to 100 mW/m2). The top of the high conductivity layer is shallower (at a depth of 100 km). The trends of major faults and other seismotectonic features have been taken into account. Based on these data (prior to November 15, 2006), the previous conclusion about the low seismic activity of the Middle Kuril Is. was corroborated. Two great earthquakes occurred in the region on November 15, 2006 (M w = 8.3) and January 13, 2007 (M w = 8.1) with subsequent tsunami waves. The erroneous inference as to low seismic activity was related to the fact that the seismic cycle in the Middle Kuril Is. may be as long as 150–200 years. We come to the conclusion that an analysis of the level of seismic activity for the region should start with the construction of standardized recurrence curves and determining the magnitude of the maximum possible earthquake. 相似文献
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P. A. Tarakanov 《Astrophysics》1999,42(2):163-168
The fractal dimensionality of the distribution of gamma-ray bursts over the celestial sphere has been investigated. Current
data from the BATSE experiment were used. A value of D2 ≈ 2 is obtained, corresponding to a uniform spatial distribution of burst sources.
Translated from Astrofizika, Vol. 42, No. 2, pp. 219–224, April–June, 1999 相似文献
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P. A. Tarakanov 《Astrophysics》2000,43(2):170-175
A possible mechanism of formation of interstellar clouds in the Galaxy by aggregation from gas “cloudlets” ejected by red
giants is considered. A numerical model of the motion of a “cloudlet” in the interstellar medium of the Galaxy is constructed.
The resulting clouds are fractal with a fractal dimensionality that coincides with the observed one. The characteristic time
of formation of a cloud agrees with observations.
Translated from Astrofizika, Vol. 43, No. 2, pp. 229–237, April–June, 2000. 相似文献
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Currents in the Drake Passage are studied using the data of a hydrographic section along the Shackleton Transverse Ridge observed in November 2007. The distribution of the velocity component normal to the section was computed by two methods: (a) directly on the basis of the lowered acoustic Doppler current profiler (LADCP) data; (b) by the calculation of geostrophic currents based on the CTD data with estimating the depth averaged velocity on the basis of the LADCP data. The main results of the research are the relatively low estimated value of the Antarctic Circumpolar Current (ACC) transport, which accounts for 65–70% of the ACC transports in December 2003 and November 2005, and the confirmation of the existence of several abyssal currents confined to the deep passages of the bottom topography. 相似文献
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