Structural interpretation of the great earthquakes of the last millennium in the central Himalaya

The life cycle of seismite research

“…Santos et al, 2012;Mugnier et al, 2013;Khorzenkov et al, 2014). The term has in the course of time even been used in the sense of a litho-unit that owes its mere existence only indirectly to the occurrence of earthquakes (e.g.…”

Constraints on Source Parameters of the 25 April 2015, M_w = 7.8 Gorkha, Nepal Earthquake from Synthetic Aperture Radar Interferometry

“…Nevertheless, we suggest that the combination of unreleased background store of energy and the strain energy accumulated since the release of high tectonic stresses associated with the 1934 Nepal-Bihar earthquake would have triggered the 25 April 2015 Gorkha, Nepal earthquake. This also testifies possible presence of seismic gaps in the region as enunciated earlier by several researchers 7,19,43 . A realistic nonlinear slip distribution model and variable dip angles along the fault plane may be required to further fortify these observations and models.…”

“…During the active thrusting of India under the Tibetan Plateau, MHT is known to absorb about 20 mm/yr convergence in Nepal, which is nearly half the present convergence rate between India and Eurasia [15][16][17][18] . The elastic strain energy thus stored during the interseismic period is released periodically due to earthquakes causing rupture along the interseismically locked, brittle upper part of the MHT system beneath the outer and lesser Himalaya, which is characterized by a southern frontal ramp (MFT) 6,7,19,20 . Whereas, aseismic slip induces stress accumulation at zones beneath the higher Himalaya, which triggers intense micro-seismic activity and elastic strain in the upper crust 13 .…”

“…Further, uncertainties involved in depth estimation using teleseismic data may be high in the Himalayan region due to local variations in seismic velocity leading to discrepancy in depth estimation between InSAR and seismic data 33 , and structural heterogeneities existing in the underthrusting Indian plate 34 . The well-accepted hypothesis for large and great earthquakes in central Himalaya includes release of interseismic strain energy along the interseismically locked portion of the MHT 18,19,35 . Recent geodetic data suggest that during the interseismic period, aseismic thrust displacement occurs in the deeper and ductile northern part of the MHT alone, while no slow earthquakes have been detected in the brittle, external locked part of the MHT 15,17,18,36,37 .…”

Detection of Land Subsidence in Kathmandu Valley, Nepal, Using DInSAR Technique

“…Also, the rupture location identity and the return time is difficult to predict [34]. Therefore, it is difficult to conduct seismic hazard assessment in highly-populated regions near the Himalayas [35].…”