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Spatio-temporal analysis of seismic potential in the Himalayas and its nearby region: an insight from seismicity and earthquake susceptibility index

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Abstract

The Himalayan region and its surrounding area are one of the most seismically active zones in the world which have significant economic and societal impact. It governs the seismicity of highly populous countries like India, China, Pakistan, Nepal, Bhutan and Afghanistan which account for more than 40% population of the world. Therefore, the complex interaction between seismic parameters and transient seismic events needs to be thoroughly addressed at the regional scale. This study highlights the spatial distribution of earthquake hazard parameters and the temporal variation in seismicity of the Himalayas and its nearby regions by employing the maximum likelihood approach using historical records as well as instrumentally recorded earthquake data of the years 1900–2021. An empirical relation is developed to convert the body wave magnitude (Mb) and surface wave magnitude (Ms) to moment magnitude (Mw). The seismic parameters, namely maximum regional magnitude (Mmax), b-value, and mean seismicity rate (λ0), are estimated for 13 defined zones. Further, the seismic behaviours of the study area are evaluated through the return periods (RP) of earthquakes and the fractal dimension (Dc) of the individual zone. Considering the temporal variation of seismicity and RP of Mw ≥ 6, a new index , i.e. earthquake susceptibility index (ESI6), is developed to identify the zones which are susceptible to Mw ≥ 6 earthquakes. The zones: Central Himalayas 2 (CH2), Western Himalayas (WH), North of MCT 1 (NMCT1) and South of MCT 2 (SMCT2) are identified to be highly susceptible to earthquakes of Mw ≥ 6. The present analysis will motivate researchers and engineers from government and non-government organizations to collaborate for improved policy making in the seismically active Himalayan region concerning land-use planning, insurance, and catastrophe preparation.

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Acknowledgements

The first author acknowledges the Ministry of Human Resources Development (MHRD), Government of India, for providing the research fellowship during this study.

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  1. Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India

    Saurav Kumar & Aniruddha Sengupta

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SK contributed to the conceptualization, writing—original draft, methodology, and formal analysis. AS was involved in writing—review and editing and supervision.

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Kumar, S., Sengupta, A. Spatio-temporal analysis of seismic potential in the Himalayas and its nearby region: an insight from seismicity and earthquake susceptibility index. Acta Geophys. 72, 1483–1507 (2024). https://doi.org/10.1007/s11600-023-01210-5

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