Automatic Seismic Zonation Based on Stress-Field Uniformity Assessed from Focal Mechanisms

2006 ◽  
Vol 96 (6) ◽  
pp. 2050-2058 ◽  
Author(s):  
P. L. Bragato ◽  
G. Bressan
Keyword(s):  
Stress Field ◽  
Focal Mechanisms ◽  
Seismic Zonation ◽  
Field Uniformity

scholarly journals Focal mechanisms and stress field in the Atotsugawa fault area, central Honshu, Japan

2010 ◽  
Vol 62 (4) ◽  
pp. 367-380 ◽  
Author(s):  
Kei Katsumata ◽  
◽  
Masahiro Kosuga ◽  
Hiroshi Katao
Keyword(s):  
Stress Field ◽  
Focal Mechanisms ◽  
Atotsugawa Fault

scholarly journals The Crustal Stress Field Inferred from Focal Mechanisms in Northern Chile

2021 ◽  
Author(s):  
Carlos Herrera ◽  
John F. Cassidy ◽  
Stan E. Dosso ◽  
Jan Dettmer ◽  
Wasja Bloch ◽  
...  
Keyword(s):  
Stress Field ◽  
Focal Mechanisms ◽  
Northern Chile ◽  
Crustal Stress ◽  
Crustal Stress Field

Spatial variation in the present-day stress field and tectonic regime of Northeast Tibet from moment tensor solutions of local earthquake data

2020 ◽  
Vol 221 (1) ◽  
pp. 478-491 ◽  
Author(s):  
Zhengyang Pan ◽  
Jiankun He ◽  
Zhigang Shao
Keyword(s):  
Stress Field ◽  
Compressive Stress ◽  
Moment Tensor ◽  
Strike Slip ◽  
Focal Mechanisms ◽  
Qilian Mountains ◽  
Compression Axis ◽  
The South ◽  
Maximum Compression ◽  
Stress Orientation

SUMMARY Focal mechanism solutions and their predicted stress pattern can be used to investigate tectonic deformation in seismically active zones and contribute to understanding and constraining the kinematic patterns of the outward growth and uplift of the Tibetan Plateau. Herein, we determined the focal mechanisms of 398 earthquakes in Northeast Tibet recorded by the China National Seismic Network (CNSN) by using the cut-and-paste method. The results show that the earthquakes predominately exhibited thrust and strike-slip faulting mechanisms with very few normal events. We then combined the derived focal mechanisms with global centroid moment tensor (GCMT) catalogue solutions and previously published solutions to predict the regional distribution of the stress field through a damped linear inversion. The inversion results show that most of region is dominated by a thrust faulting regime. From the southern East Kunlun fault in the west to the northern Qilian Mountains along the Altyn Tagh fault (ATF), the maximum compression axis rotates slightly clockwise; farther to the south of the Haiyuan fault in the east, there is an evident clockwise rotation of the maximum compression axis, especially at the eastern end of the Haiyuan fault. In the Qilian Mountains, the axis of the compressive stress orientation approximately trends NE–SW, which does not markedly differ from the direction of India–Eurasia convergence, emphasizing the importance of the compressive stress in reflecting the remote effects of this continental collision. The overall spatial pattern of the principal stress axes is closely consistent with the GPS-derived horizontal surface velocity. A comparison of the stress and strain rate fields demonstrated that the orientations of the crustal stress axes and the surface strain axes were almost identical, which indicates that a diffuse model is more suitable for describing the tectonic characteristics of Northeast Tibet. Additionally, the compressive stress orientation rotated to ENE–WSW in the northern Qilian Mountains along the ATF and to ENE–WSW or E–W along the eastern part of the Haiyuan fault and its adjacent area to the south, highlighting the occurrence of strain partitioning along large left-lateral strike-slip faults or the lateral variation of crustal strength across these faults. Combining geodetic, geological and seismological results, we suggest that a hybrid model incorporating both the diffuse model associated with shortening and thickening of the upper crust and the asthenospheric flow model accounting for the low-velocity zone in the middle-lower crust may reflect the primary mode of crustal deformation in Northeast Tibet.

Stress field in the Transcarpathians from focal mechanisms

2017 ◽  
Author(s):  
D.V. Malytskyy ◽  
A.V. Murovska ◽  
O.O. Obidina ◽  
O.B. Gintov ◽  
A.R. Gnyp ◽  
...  
Keyword(s):  
Stress Field ◽  
Focal Mechanisms

scholarly journals Determining the Stress Field in Active Volcanoes Using Focal Mechanisms

2016 ◽  
Vol 4 ◽  
Author(s):  
Bruno Massa ◽  
Luca D'Auria ◽  
Elena Cristiano ◽  
Ada De Matteo
Keyword(s):  
Stress Field ◽  
Focal Mechanisms ◽  
Active Volcanoes

scholarly journals The recent fault kinematics in the westernmost part of the Getic nappe system (Eastern Serbia): Evidence from fault slip and focal mechanism data

2014 ◽  
Vol 65 (2) ◽  
pp. 147-161 ◽  
Author(s):  
Ana Mladenović ◽  
Branislav Trivić ◽  
Milorad Antić ◽  
Vladica Cvetković ◽  
Radmila Pavlović ◽  
...  
Keyword(s):  
Stress Field ◽  
Active Fault ◽  
Local Stress ◽  
Tectonic Stress ◽  
Research Area ◽  
Strike Slip ◽  
Fault Slip ◽  
Focal Mechanisms ◽  
Fault Systems ◽  
Fault Kinematics

Abstract In this study we performed a calculation of the tectonic stress tensor based on fault slip data and all available focal mechanisms in order to determine the principal stress axes and the recent tectonic regime of the westernmost unit of the Getic nappe system (Gornjak-Ravanica Zone, Eastern Serbia). The study is based on a combined dataset involving paleostress analyses, the inversion of focal mechanisms and remote sensing. The results show dominant strike-slip kinematics with the maximal compression axis oriented NNE-SSW. This is compatible with a combined northward motion and counterclockwise rotation of the Adria plate as the controlling factor. However, the local stress field is also shown to be of great importance and is superimposed on the far-field stress. We managed to distinguish three areas with distinct seismic activity. The northern part of the research area is characterized by transtensional tectonics, possibly under the influence of the extension in the areas situated more to the northeast. The central and seismically most active part is dominated by strike-slip tectonics whereas the southern area is slightly transpressional, possibly under the influence of the rigid Moesian Platform situated to the east of the research area. The dominant active fault systems are oriented N-S (to NE-SW) and NW-SE and they occur as structures of either regional or local significance. Regional structures are active in the northern and central part of the study area, while the active fault systems in the southern part are marked as locally important. This study suggests that seismicity of this area is controlled by the release of accumulated stress at local accommodation zones which are favourably oriented in respect to the active regional stress field.

Stress field estimation based on focal mechanisms and back projected imaging in the Eastern Llanos Basin (Colombia)

2016 ◽  
Vol 71 ◽  
pp. 320-332 ◽  
Author(s):  
Sebastián Gómez-Alba ◽  
Carlos Eduardo Fajardo-Zarate ◽  
Carlos Alberto Vargas
Keyword(s):  
Stress Field ◽  
Focal Mechanisms ◽  
Field Estimation
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