Assessment of seismic hazard in Uttarakhand Himalaya

Abstract

Purpose

For a state like Uttarakhand, which is located in the seismically active Himalayan region and in the vicinity of plate boundaries, estimation of seismic hazards and the preparation of a zoning map are an urgent necessity. This paper aims to focus on this hazard.

Design/methodology/approach

In total, 32 potential seismo‐tectonic source zones were identified in a very wide area in and around the state, on the basis of seismicity and tectonics, and the longer ones were segmented. The maximum magnitude that each seismo‐tectonic source zone can support was then estimated. The seismic hazard due to each seismo‐tectonic source zone was assessed at 180 sites, in terms of peak ground acceleration (PGA).

Findings

The maximum PGA at each site varied between 0.06g and 0.50g. The seismic hazard was highest around the main central thrust and the main boundary thrust, and five other thrusts between these two thrusts. This assessment was adapted to make a seismic zoning map of Uttarakhand, with five distinct zones.

Research limitations/implications

If seismo‐tectonic source zones from the contiguous regions of Nepal and Tibet were included as part of this assessment, then a higher hazard would be expected in Uttarakhand.

Practical implications

Threat perceptions of a potential earthquake disaster can be assessed in this zoning map. Disaster mitigation strategies will vary geographically, with priorities defined by the zoning map presented here. The methodology evolved has the potential to be extended to other vulnerable states in the Himalayan arc.

Originality/value

The seismic hazard assessed has been adapted to formulate a seismic zoning map of Uttarakhand.

Citation

Kumar, P., Kumar, A. and Sinvhal, A. (2011), "Assessment of seismic hazard in Uttarakhand Himalaya", Disaster Prevention and Management, Vol. 20 No. 5, pp. 531-542. https://doi.org/10.1108/09653561111178961