Fault zones and stress fields of the Earth’s crust in the vicinity of Ulaanbaatar (Mongolia) at the modern stage of tectogenesis

2017 ◽  
Vol 474 (1) ◽  
pp. 511-515 ◽  
Author(s):  
K. Zh. Seminsky ◽  
S. Demberel ◽  
D. Mungunsuren
2021 ◽  
Vol 12 (3) ◽  
pp. 435-454
Author(s):  
T. L. Ibragimova ◽  
R. S. Ibragimov ◽  
M. A. Mirzaev ◽  
Yu. L. Rebetsky

The current stress of Earth's crust in the territory of Uzbekistan has been studied using a focal earthquake mechanisms catalogue that includes the data provided by many authors. Stress reconstructions are based on the cataclastic analysis of displacements along fractures. For reconstructing the stress state at different depths of the crust in several seismically active regions of the study area, we consider a minimum number of earthquakes in a homogeneous sample equal to 6 and an averaging radius of 10 to 30 km within a single domain. The azimuths and dip angles of the principal stress axes, Lode – Nadai coefficients, geodynamic types of stress modes, relative (normalized to rock strength) values of maximum shear stresses, and effective pressure values are determined. Maps showing the spatial distribution of the studied parameters are constructed for both the entire seismically active layer and the depth layers. Stress fields are reconstructed and compared at two hierarchical levels based on the parameters of focal mechanisms of weak and moderate earthquakes (М≤4.5) and those of strong (М≥5.0) earthquakes. "Tectonic Stresses of Eurasia", the Internet resource created by IPE RAS, is used to visualize the stress field reconstructed from the data on strong (М≥5.0) earthquakes.


2003 ◽  
Vol 112 (6) ◽  
pp. 897-914 ◽  
Author(s):  
Norio SHIGEMATSU ◽  
Koichiro FUJIMOTO ◽  
Tomoyuki OHTANI ◽  
Hidemi TANAKA ◽  
Yukari MIYASHITA ◽  
...  

2019 ◽  
Vol 18 (4) ◽  
pp. 460-474
Author(s):  
Tran Tuan Dung ◽  
R. G. Kulinich ◽  
Ngo Thi Bich Tram ◽  
Nguyen Quang Minh ◽  
Nguyen Ba Dai ◽  
...  

Present-day stress filed in the Hoang Sa archipelago and adjacent areas is determined through the earthquake’s focal mechanism parameters that have been recorded during a time period of more than 100 years. The geometric parameters of the faults (such as the location, strike and dip angles as well as depth, length…) are determined by satellite-derived gravity, seismic data and stress fields. In this study, predictive determination of the magnitude and tendency of the relative displacement of the Earth’s crust is carried out by calculating and assessing the relationship between the stress fields and fault’s geometric parameters. On the basis of the Earth’s crust relative displacement, the geodynamic mechanism of the Hoang Sa archipelago and adjacent areas through the different geological periods can be rebuilt. Magnitude and tendency of the relative displacement of the Earth’s crust are represented by the color spectrum and the vector’s magnitude. Although the displacement appears in the whole region, its intensities are different in particular areas that have the faults systems with different grades.


1915 ◽  
Vol 79 (2058supp) ◽  
pp. 382-383
Author(s):  
Alphonse Berget

2017 ◽  
Vol S36 ◽  
pp. 3-10
Author(s):  
P. G. Dyadkov ◽  
◽  
L. V. Tsibizov ◽  
M. P. Kozlova ◽  
A. V. Levicheva ◽  
...  

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