排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
2.
Usoltseva O. A. Ovtchinnikov V. M. Krasnoshchekov D. N. 《Izvestiya Physics of the Solid Earth》2021,57(1):84-97
Izvestiya, Physics of the Solid Earth - Abstract—The structure of seismic wavefield at distances close to antipodal is analyzed using two numerical methods—DSM and AXISEM—for... 相似文献
3.
V. M. Ovtchinnikov P. B. Kaazik D. N. Krasnoshchekov 《Izvestiya Physics of the Solid Earth》2012,48(3):211-221
Experimental data on the differential travel time t
BC–t
DF of seismic waves PKPDF and PKPBC in the Earth’s core under Africa and Australia are analyzed. The differential travel-time residuals beneath Africa in a narrow
range of angles from 21° to 25° between the direction of the seismic ray in the core and the Earth’s rotation axis exhibit
a scoop-shaped peculiarity not accounted for by cylindrical anisotropy in the inner core. A model with a 0.2–0.8% P-wave velocity anomaly with a radius of 1375 km in the cylindrical region in the outer core is proposed, which closely fits
the experimental data. We suggest that the velocity anomaly is generated by the dynamical processes occurring in the outer
core, namely, the growth of the inner core and the convection in the outer core, both leading to the formation of a low-density
anomaly in the outer core. 相似文献
4.
5.
Izvestiya, Physics of the Solid Earth - Abstract—The paper presents the review of the conceptually most important results of seismological studies of the Earth’s core and their... 相似文献
6.
Krasnoshchekov D. N. Ovtchinnikov V. M. Usoltseva O. A. 《Doklady Earth Sciences》2019,488(2):1186-1189
Doklady Earth Sciences - Analysis of PKIIKP waves reflected off the inner surface of the solid core boundary and recorded close to the antipode indicates that the shear wave velocity at its top can... 相似文献
7.
8.
Krasnoshchekov D. N. Ovtchinnikov V. M. Usoltseva O. A. 《Izvestiya Physics of the Solid Earth》2021,57(5):593-604
Izvestiya, Physics of the Solid Earth - Abstract—Based on the alpha-shape computer-graphics analysis of coda envelope of the waves from nuclear explosions reflected from the inner core... 相似文献
9.
I. P. Bashilov S. G. Volosov S. A. Korolyov V. A. Merkulov V. M. Ovtchinnikov O. V. Ovtchinnikova 《Seismic Instruments》2016,52(3):253-265
A family of seismometers has been developed with capacitive transducers that convert the relative displacement between the inertial mass and the base of the device into an electric signal. The seismometers have high sensitivity and a unified electronic circuit, and they can be rather easily manufactured, installed, and calibrated. Mass production of these instruments looks promising. To assess the possibility of using these seismometers as substitutes for imported counterparts, a comparative analysis was carried out to study the performance of an SM-3E broadband sensor with a capacitive transducer and imported STS-2 and CMG-6T seismometers. Seismic recordings of these three instruments mounted on the same pedestal were statically analyzed in the time and frequency domains. 相似文献
10.
The results of analysis of more than 1300 new PKiKP/PcP amplitude ratios measured in Southeast Asia and South America at the epicentral distances of 3.2°–35.2° are presented. The density jump in the Eastern Hemisphere of the Earth’s inner core (IC) is 0.3 g/cm3, and it is 0.9 g/cm3 in the Western one. Taking the large discrepancy in the obtained estimates into consideration, maintenance of such large lateral variations in the mosaic properties of the IC reflecting surface requires considerable variations in the thermodynamic parameters (mostly temperature) of the inner–outer core transition. However, if the observed asymmetry in the density jump distribution is of a global character, the data presented support the translation model of the IC dynamics. This model implies IC crystallization in the Western Hemisphere and melting in the Eastern one, not vice versa, as suggested by another geodynamic model based on thermochemical convection in the outer core and the thermal balance of the core–mantle system. 相似文献