Skip navigation
Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/6477
Title: A plausible model for the present day seismicity and tectonic activity in the Hindukush complex zone
Authors: Singh V.P.
Duda J.
Shanker D.
Published in: Journal of Asian Earth Sciences
Abstract: The Hindukush zone is situated on the northern boundary of the Indian Plate along its northwestern flanks. Fifteen years (1974-1988) of seismic data published by United States Coast and Geodetic Surveys (USCGS) and focal mechanism solutions of the subducted lithosphere, reported by different scientists, have been used to model the seismic and tectonic characteristics of the Hindukush complex zone. The data indicate that the zone can be separated into two seismic segments, OP and PQ, with a V-shaped pattern, striking E-W and NE-SW, respectively. The two segments do not represent well-defined subduction zones, as the depth and frequency of events is not uniformly distributed. The E-W striking segment extends from 68.2°E to 70.5°E at about 36.5° N, whereas the northeast-southwest segment extends from 36.5°N, 70.5°E to 38°N, 73°E. The frequency and depth of earthquakes are greatest at 36.5°N, 70.5°E decreasing towards the W and NE. Focal mechanism solutions (thrust and normal faulting) for the Hindukush zone suggest that the directions of stress may be grouped into: 1. Compressive forces acting NE-SW for the east-west striking segment. For the NE-SW striking seismic segment compressive forces are directed towards the NW; 2. Compressive forces are also acting along the strike of the two seismic segments; and 3. The direction of the tensile stress is different in each segment and extends to a depth of up to 221 km. A model is proposed to explain the distribution of earthquake foci in terms of the V-shaped subduction of oceanic lithosphere, with tensile, and compressive stresses in the two seismic belts being due to the upper mantle flow of the Indian Plate and the Tibetan Plateau. The sinking of the mantle in the Hindukush zone is responsible for the stretching of the seismic slab in a vertical direction, giving rise to the present earthquake frequency and focal depth distribution pattern. © 2004 Elsevier Ltd. All rights reserved.
Citation: Journal of Asian Earth Sciences (2005), 25(1): 147-156
URI: https://doi.org/10.1016/j.jseaes.2004.02.002
http://repository.iitr.ac.in/handle/123456789/6477
Issue Date: 2005
Keywords: Continental collision
Eurasian plate
Subduction zone
Tibetan Plateau
V-shaped structure
ISSN: 13679120
Author Scopus IDs: 57195152063
49161004900
57206167454
Author Affiliations: Singh, V.P., Department of Geophysics, Faculty of Science, Banaras Hindu University, Varanasi 221 005, India
Duda, J., Institute fur Geophysik, Bundesstr. 55, Hamburg 20146, Germany
Shanker, D., Department of Earthquake Engineering, Indian Institute of Technol. Roorkee, Roorkee 247667 Uttaranchal, India
Funding Details: We wish to thank the reviewers for critically examining the manuscript and offering very valuable suggestions and to the Deputy Editor-in-Chief Dr A.J. Barber, for his efforts throughout publication. The research project was supported by Deutsche Forschungs Gemeinschaft, Germany. The first author thanks to DFG for awarding the fellowship in India National Science Academy and DGH exchange Programme. Third author is indebted to Head, Department of Earthquake Engineering, Indian Institute of Technology Roorkee for providing excellent computational facilities.
Corresponding Author: Shanker, D.; Department of Earthquake Engineering, Indian Institute of Technol. Roorkee, Roorkee 247667 Uttaranchal, India; email: dayasfeq@iitr.ernet.in
Appears in Collections:Journal Publications [EQ]

Files in This Item:
There are no files associated with this item.
Show full item record


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.