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1.
Various parameters of seismic field are considered for the Caucasian region. The most informative appeared to be the “sigma-Σ” parameter. A sketch map of the geotectonic zoning of the Caucasus is shown in which the σ parameter is represented by isolines for all periods under consideration. A comparative analysis of the values of the sigma-Σ parameter was conducted in each elemental area for three successive decades. Zones which are characterized by an unstable behaviour of the parameter can be distinguished. 相似文献
2.
N. V. Kondorskaya L. B. Slavina N. B. Pivovarova B. K. Balavadze M. A. Alexidze S. D. Gotsadze G. I. Marusidze D. I. Sikharulidze N. I. Pavlenkova E. A. Khrometskaya G. V. Krasnopevtseva 《Pure and Applied Geophysics》1981,119(6):1167-1179
This paper deals with a procedure of a joint analysis of seismic data from earthquakes and those obtained by DSS. The DSS data are used as a first approximation to construct a two-dimensional model of the medium made up of individual blocks. These models serve as a basis when constructing specific three-dimensional travel-time curves. These travel-time curves are further used for the calculation of hypocenter parameters in a laterally inhomogeneous block medium.The hypocenter field and the travel times obtained are input data for the computation of three-dimensional fields of velocities in earthquake focal zones. Results of applying the proposed procedure to the Caucasus region are presented. 相似文献
3.
A method was developed to obtain from a signal station the spatial and temporal distribution ofV
p
/V
s
ratios before earthquakes of magnitude>6. It was shown thatV
p
/V
s
values strongly depend upon the relative positions of the stations, the future large earthquake and the foci of the smaller earthquakes used forV
p
/V
s
determination. The appearance of a zone of anomalousV
p
/V
s
values with linear dimensions of the order of 100 km was noted at least 4 years before a deep earthquake of magnitude 7. Similar size anomalous zones were detected one year before some magnitude 6 earthquakes.
V
p
/V
s
values decreased by a small but distinct amount during this time. Additionally, local short term minima inV
p
/V
s
ratios were observed some months before the major event. The epicenters of the large earthquakes were located within the 100 km size zone where the gradients of theV
p
/V
s
field were largest. 相似文献
4.
N. V. Kondorskaya L. B. Slavina N. B. Pivovarova V. B. Sollogub A. V. Chekunov E. A. Sagalova Y. K. Shchukin 《Pure and Applied Geophysics》1981,119(6):1157-1166
The joint analysis performed for the Carpathian region from seismological data (three-dimensional fields of velocities, areas of concentration of earthquake foci in the Vrancea focal zone) and interpretation of DSS data and those of other geophysical fields have permitted to obtain new evidence for the earth's crust and mantle structure in this region. 相似文献
5.
L. B. Slavina N. B. Pivovarova S. L. Senyukov 《Journal of Volcanology and Seismology》2012,6(2):100-115
P- and S-wave travel times from local volcanic earthquakes recorded in the North group of volcanoes area during the 2005–2009 period
were treated by the “reverse wave” method to calculate the V
P
velocity field and the TAU parameter, which is an analogue of the P- to S-wave velocity ratio. We constructed 3D velocity distributions along the line traversing the volcanic group along the direction
from Ploskii Tolbachik Volcano in the southwest toward Shiveluch Volcano in the northeast. Dynamic changes in the velocity
field were identified, both over time and depth. We examine the relationships of these dynamic changes to the evolution of
volcanic activity during the period indicated. 相似文献
6.
L. B. Slavina N. B. Pivovarova S. L. Senyukov 《Izvestiya Atmospheric and Oceanic Physics》2012,48(7):696-705
The results of a calculation of the P-wave (V P ) velocity fields are presented on the basis of the method of the reversible wave and the TAU parameter characterizing the V P /V S ratio of seismic waves from the local volcanic earthquakes that occurred at the northern group of Kamchatka volcanoes in 2005–2007. The 3D velocity cross sections were constructed along the SW-NE-trending volcanic group from the Ploskii Tolbachik volcano in the southwest up to the Shiveluch volcano in the northeast. The change of velocity field in time and depth is found. The problems of relating these changes to volcanic activity is reviewed. 相似文献
7.
8.
9.
L. B. Slavina N. B. Pivovarova V. I. Levina 《Journal of Volcanology and Seismology》2009,3(5):326-337
We present computations of 3D P-wave velocity field for the segment of the Benioff zone of Kamchatka between 51.5° N to Avacha Bay to Cape Shipunskii to
Kronotskii Bay. P-wave travel times for regional earthquakes were used to compute and construct 3D models of the velocity field for this segment
of the Benioff zone. We examined the velocity structure to interpret it in conjunction with neotectonic morphostructures.
The computations showed a complex structure of the field and the presence of inhomogeneities, both along and across the Benioff
zone. Of special interest are the results for the Avacha and Kronotskii basins, where high velocity masses are unusually shallow
beneath the low velocity layers in the top of the earth section. This creates high-gradient zones that can possibly generate
large earthquakes. 相似文献
10.
Slavina L. B. Kuchai M. S. Likhodeev D. V. Senyukov S. L. 《Izvestiya Atmospheric and Oceanic Physics》2019,55(8):816-839
Izvestiya, Atmospheric and Oceanic Physics - The dynamics of the volcanic activity, magmatic feeding system, accumulation, movement, and composition of magmas, and structure of the roots of the... 相似文献