scholarly journals Upper mantle of Baikal and Transbaikalia according to the area data of seismological research

2020 ◽  
Vol 2 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Victor Solovyev ◽  
Viktor Seleznev ◽  
Vladimir Chechelnitsky ◽  
Natalya Galyova
Keyword(s):  
Upper Mantle ◽  
Velocity Structure ◽  
Baikal Rift Zone ◽  
Research Area ◽  
Southeastern Part ◽  
Transverse Waves ◽  
S Waves ◽  
New Information ◽  
Seismological Data ◽  
Boundary Velocity

According to the areal interpretation of seismological data from sufficiently strong earth-quakes, new information on the velocity structure of the upper mantle of the Baikal and Trans-Baikal regions is presented. Based on the results of a tomographic interpretation of the travel times of P and S waves from the Mokhorovichich border, maps of the boundary velocities of longitudinal and transverse waves in the Baikal and Transbaikalia, the ratios of the velocities of the P and S waves (Vp/Vs), and the distribution of the Poisson's ratio (σ) are constructed. The boundary velocity in the northwestern, northern, and northeastern parts of the research area (within the Baikal rift zone) according to longitudinal and transversal waves has lower values of 7.80-7.95 km/s and 4.45-4.55 km/s, respectively. In the upper mantle of the southeastern part of the area, the mantle block is about 600x600 km in size with high longitudinal and transversal wave’s velocities of 8.40-8.45 km/s and 4.80-4.85 km/s, respectively, and increased values of Vp/Vs and σ. The assumption of its nature as a plate of eclogites (or eclogite-like rocks) in the region of the Mongol-Okhotsk orogenic belt is justified. The results were compared with materials from other research.

scholarly journals FEATURES OF THE DEEP VELOCITY STRUCTURE OF THE TRANS-BAIKAL SECTION OF THE CENTRAL ASIAN FOLDED BELT FROM SEISMOLOGY AND GPS DATA (IN THE ALIGNMENT OF THE REFERENCE PROFILE 1-SB)

2020 ◽  
Vol 39 (5) ◽  
pp. 56-68
Author(s):  
V.M. Solovyev ◽  
◽  
A.S. Salnikov ◽  
V.S. Seleznev ◽  
V.V. Chechelnitsky ◽  
...  
Keyword(s):  
Baikal Region ◽  
Velocity Structure ◽  
Baikal Rift Zone ◽  
Earth’S Crust ◽  
S Wave ◽  
Southeastern Part ◽  
S Waves ◽  
Central Asian ◽  
Boundary Velocity ◽  
Earth's Crust

The materials of deep seismic studies on the reference geophysical profile 1-SB and areal interpretation of seismological data in the Trans-Baikal part of the Central Asian folded belt are presented. It is shown that longitudinal and transverse waves from the reference boundaries in the Earth's crust and Moho surface were registered using explosions and powerful vibration sources on the 1200-km geophysical profile 1-SB in Trans-Baikal region. The inhomogeneous velocity structure (according to P - and S - waves) of the upper part of the Earth's crust to the depths of 15–20 km and Moho surface was established. The anomalous mantle with reduced values of the boundary velocity of P - and S-waves (7.8–7.95 km/s and 4.3–4.5 km/s, respectively) was reliably traced within the Baikal rift zone using GSS and seismology data. In the southeastern part of the area (in the central Mongol-Okhotsk orogenic belt and adjacent folded structures of the Trans-Baikal region), a layer of increased P-and S-wave velocity values on was detected the mantle surface at 8.4 ± 0.15 km/s and 4.9 ± 0.05 km/s, respectively. A comparison was made with the materials of other studies.

Velocity structure of the crust and upper mantle in the Baikal rift zone from the long-term observations of broad-band seismic stations

2009 ◽  
Vol 428 (1) ◽  
pp. 1067-1070 ◽  
Author(s):  
L. V. Anan’in ◽  
V. V. Mordvinova ◽  
M. F. Gots’ ◽  
M. Kanao ◽  
V. D. Suvorov ◽  
...  
Keyword(s):  
Upper Mantle ◽  
Rift Zone ◽  
Velocity Structure ◽  
Broad Band ◽  
Baikal Rift Zone ◽  
Crust And Upper Mantle ◽  
Seismic Stations

scholarly journals ANALYSIS OF THE DEEP SEISMIC STRUCTURE AND SEISMICITY OF THE TRANSBAIKALIA (ALONG THE 1-SB PROFILE)

2019 ◽  
Vol 2 (2) ◽  
pp. 224-233
Author(s):  
Victor Solovyev ◽  
Alexander Salnikov ◽  
Viktor Seleznev ◽  
Vladimir Chechelnitsky ◽  
Nadezhda Gilyova ◽  
...  
Keyword(s):  
Rift Zone ◽  
Velocity Structure ◽  
Deep Structure ◽  
Baikal Rift Zone ◽  
Earth’S Crust ◽  
Seismic Structure ◽  
Elastic Parameters ◽  
S Waves ◽  
Close Proximity ◽  
Earth's Crust

An analyzing on the seismicity and the deep structure of Transbaikalia along the 1-SB profile is presented. Determined that areas of high seismicity associated with the blocks of the Earth's crust with a heterogeneous velocity structure. The site of the Baikal rift zone which is located in close proximity to the Muya earthquake (1957, M=7.6) is characterized by increased heterogeneity according to the values of P- and S-waves and of elastic parameters in the Earth’s crust upper part.

scholarly journals VELOCITY MODEL OF CRUST OF AZERBAIDJAN ON DATA OF DIGITAL SEISMIC STATIONS

2012 ◽  
Author(s):  
Г.Д. Етирмишли ◽  
С.Э. Казымова
Keyword(s):  
Velocity Structure ◽  
Three Dimensional ◽  
Velocity Model ◽  
Design Calculation ◽  
Travel Times ◽  
Seismic Stations ◽  
One Dimensional ◽  
S Waves ◽  
Velocity Models ◽  
Seismological Data

При изучении скоростной структуры земной коры Азербайджана по сейсмологическим данным ис- пользовались в основном два подхода. Первый состоит в уточнении модели среды на основании наблюда- емых отклонений времен пробега волн от землетрясений относительно стандартного годографа. Второй основан на использовании разности времен пробега от источников до станции для групп близко располо- женных событий. Одномерные скоростные модели Р и S-волн были построены на основе одномерных моделей, пред- ложенных в работе Гасанова А.Г. Построение модели, расчет станционных поправок и перелокация со- бытий производились в программе Velest. Исследуемый объем до глубины 60 км был разбит на мелкие слои толщиной 2 км в интервале глубин 010 км и толщиной 510 км в интервале глубин 1060 км. В ходе исследования рассматривались сейсмологические данные о параметрах локальных землетрясений и вре- менах прихода P и S-волн зарегистрированных сетью телеметрических станций за период 20042011 гг. Анализировались данные 28-ми сейсмических станций Азербайджана, охватывающие всю исследуемую территорию. Для расчета трехмерного скоростного поля использовалась программа TomotetraFD. В этой програм- ме реализован классический сейсмотомографический метод для случая, когда источники и приемники находятся внутри исследуемого региона. Two approaches were used for investigation of crust velocity structure of Azerbaijan on the basis of seismological data. The first one consists in medium model adjustment on the basis of observed deviation of travel times of waves from earthquakes relative to standard hodograph. The second is based on difference in travel times from source to station for a group of close located stations. One dimensional velocity models of P- and S-waves were constructed on the basis of one dimensional models proposed by A.G.Gasanov. Model design, calculation of stations corrections and relocationing of events 74 Геология и геофизика Юга России, 1, 2012 were performed in Velest program. Investigating volume to depth of 60 km was divided in small layers of 2 km thickness in 0-10 km interval and 5-10 km in 10-60 km interval. Seismological data about parameters of local earthquakes registered by network of telemetric stations in 2004-2011 and arrival times of P- and S-waves were used. Data of 28 seismic stations of Azerbaijan covering all the investigating territory were analyzed. Three dimensional velocity field was calculated by means of TomotetraFD program. Classical seismotomographical method for the case when sources and receivers are located within investigating region is realized in the program.

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