Publication Date:
2015-12-10
Description:
Groundwater usage in the Indo-Gangetic plains exceeds replenishment of aquifers, leading to substantial reduction in the mass. Such anthropogenic crustal unloading may promote long-term fault slip or may modulate seismic activity in the adjoining Himalayan region. Our simulation using GRACE data and hydrological models of such a process indicates that the thrust earthquakes on the Main Himalayan Thrust (MHT), including the recent April 25, 2015 Mw 7.8 Gorkha, Nepal earthquake, are probably influenced by the anthropogenic groundwater unloading process in the Gangetic plains. The groundwater withdrawal leading to crustal unloading in the Gangetic plains causes a significant component of horizontal compression which adds to the secular interseimic compression at the seismogenic depth (5–20 km) on the MHT beneath the Himalayan arc, and at hypocentral depth of the 2015 Gorkha, Nepal earthquake. This effect enhances the Coulomb stress on the locked zone of MHT.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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