Low seismicity in the Bhutan Himalaya and the stress shadow of the 1897 Shillong Plateau earthquake

The seismicity of the Bhutan Himalaya region is generally low as compared to its adjoining Himalayan segments. The topography in the region is slightly subdued and different from the neighbouring central Nepal region. Low seismicity in the region may possibly be due to the postulated low convergence rate in the Bhutan Himalaya, difference in subsurface structures, or the aseismic nature of the region. We suggest that the lower seismicity in the Bhutan Himalaya may also be due to stress change caused by the great 1897 Shillong Plateau earthquake as the low seismicity region of the Bhutan Himalaya coincides with the stress shadow of the earthquake.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The seismicity is generally low in the Bhutan Himalaya. ► Low seismicity may imply that the region is accumulating strain for a future great earthquake. ► We suggest that the low seismicity could be due to the stress shadow of the great 1897 Shillong Plateau earthquake.