Analysis of the Maximum Principal Stress Directions in the Himalayas: A Remote Sensing Based Approach.
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| Title: | Analysis of the Maximum Principal Stress Directions in the Himalayas: A Remote Sensing Based Approach. |
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| Authors: | Nath, S.1,2 (AUTHOR) somalinnath@gmail.com, Chatterjee, R. S.1 (AUTHOR), Mohanty, S. P.2 (AUTHOR), Sharma, A.1 (AUTHOR), Prasad, A. V.1 (AUTHOR) |
| Source: | Geotectonics. Jan2021, Vol. 55 Issue 1, p83-93. 11p. |
| Subject Terms: | *Microwave remote sensing, *Remote sensing, *Remote sensing by radar, *Strike-slip faults (Geology), *Optical radar, *Internal friction, *Optical remote sensing |
| Geographic Terms: | Himalaya Mountains |
| Abstract: | The tectonic activity in the Himalayan region is reflected through major and minor lineaments associated with the major fault and thrust systems. In the present study, we used multi-sensor optical and microwave radar remote sensing images and topographic elevation data for extraction of lineaments. Image enhancement of remote sensing data and relief shading of topographic elevation data were performed for highlighting the lineaments. Eight structural domains were selected in and around the major thrusts and strike slip faults in north-western and central Himalayan regions. From the angular distribution of lineaments, the vector mean orientations of major and minor lineaments were determined for each of the structural domains. Considering areal coverage of individual litho-units, area-weighted internal friction angles were obtained for eight structural domains. Finally, based on the Mohr-Coulomb failure criteria, the directions of maximum principal stress (s1) were estimated from the orientations of shear fractures. The study shows a good agreement between minor lineaments based maximum principal stress directions and GPS based plate motion vectors. But, we found a significant deviation between major and minor lineaments based principal stress directions and plate motion vectors for some of the structural domains those were affected by post-thrusting strike-slip fault tectonics. This is perhaps due to the fact that major lineaments give rise to the maximum principal stress direction of older collision and post-collision phases whereas minor lineaments represent essentially recent to sub-recent active tectonics phase. Further, subtle local deviations in the principal stress directions may be attributed to litho-tectonic heterogeneities. [ABSTRACT FROM AUTHOR] |
| Database: | Energy & Power Source |
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| Abstract: | The tectonic activity in the Himalayan region is reflected through major and minor lineaments associated with the major fault and thrust systems. In the present study, we used multi-sensor optical and microwave radar remote sensing images and topographic elevation data for extraction of lineaments. Image enhancement of remote sensing data and relief shading of topographic elevation data were performed for highlighting the lineaments. Eight structural domains were selected in and around the major thrusts and strike slip faults in north-western and central Himalayan regions. From the angular distribution of lineaments, the vector mean orientations of major and minor lineaments were determined for each of the structural domains. Considering areal coverage of individual litho-units, area-weighted internal friction angles were obtained for eight structural domains. Finally, based on the Mohr-Coulomb failure criteria, the directions of maximum principal stress (s1) were estimated from the orientations of shear fractures. The study shows a good agreement between minor lineaments based maximum principal stress directions and GPS based plate motion vectors. But, we found a significant deviation between major and minor lineaments based principal stress directions and plate motion vectors for some of the structural domains those were affected by post-thrusting strike-slip fault tectonics. This is perhaps due to the fact that major lineaments give rise to the maximum principal stress direction of older collision and post-collision phases whereas minor lineaments represent essentially recent to sub-recent active tectonics phase. Further, subtle local deviations in the principal stress directions may be attributed to litho-tectonic heterogeneities. [ABSTRACT FROM AUTHOR] |
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| ISSN: | 00168521 |
| DOI: | 10.1134/S0016852121010088 |
