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Travel times ofP-waves in North-East India

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Summary

Based on 90 accurately localized earthquakes in and around North-East India and the local crustal velocity model of Gupta et al. [4], the travel times of P-waves have been determined from the foci of these earthquakes at arbitrarily selected depths of 5, 13, 25, 41 and 50 km to the sites of the seismic stations operated by the Regional Research Laboratory, Jorhat and the National Geophysical Research Institute, Hyderabad, and also to the sites of the Shillong and Tura seismic stations run by the India Meteorological Department, New Delhi. The travel times of P-waves fit a straight line very well with velocities of 5·97 ± 0·31, 6·18 ± 0·01, 6·41 ± 0·03, 7·82 ± 0·07 and 7·95 ± 0·01 km/sec at each of the depths under study. Similar investigations of P* and Pg-waves of 16 earthquakes at a depth of 10 km have revealed velocities of 6·53 ± 0·31 and 5·64 ± 0·34 km/sec, respectively. A simplified two-layered crustal model consisting of an average crustal thickness of 41·5 km with 22·2 and 19·3 km thick layers has been obtained.

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Authors and Affiliations

  1. Regional Research Laboratory, 785006, Jorhat, Assam, India

    M. V. D. Sitaram, P. G. Rao & M. M. Saikia

  2. Oil and Natural Gas Commission, Jorhat, Assam, India

    George John

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  1. M. V. D. Sitaram
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  2. George John
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  3. P. G. Rao
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  4. M. M. Saikia
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Sitaram, M.V.D., John, G., Rao, P.G. et al. Travel times ofP-waves in North-East India. Stud Geophys Geod 34, 96–109 (1990). https://doi.org/10.1007/BF02295830

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  • DOI: https://doi.org/10.1007/BF02295830

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