2016/01/11 by John R. Elliott, Romain Jolivet, Pablo J. González +4 · 448 citations
Earth and Planetary Sciences · #earthquake and tectonic studies #Geological and Geochemical Analysis #High-pressure geophysics and materials #Geology #Seismology #Thrust fault #Geodetic datum #Thrust #Seismic gap #Fault (geology) #Magnitude (astronomy) #Subduction #Earthquake magnitude #Tectonics #Geodesy #Geometry
paper · pdf · doi:10.1038/ngeo2623
published in Nature Geoscience 9(2), 174-180 (Nature Portfolio)
openalex publication_date 2016/01/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
The Himalayan mountain range has been the locus of some of the largest continental earthquakes, including the 2015 magnitude 7.8 Gorkha earthquake. Competing hypotheses suggest that Himalayan topography is sustained and plate convergence is accommodated either predominantly on the main plate boundary fault, or more broadly across multiple smaller thrust faults. Here we use geodetic measurements of surface displacement to show that the Gorkha earthquake ruptured the Main Himalayan Thrust fault. The earthquake generated about 1 m of uplift in the Kathmandu Basin, yet caused the high Himalaya farther north to subside by about 0.6 m. We use the geodetic data, combined with geologic, geomorphological and geophysical analyses, to constrain the geometry of the Main Himalayan Thrust in the Kathmandu area. Structural analyses together with interseismic and coseismic displacements are best explained by a steep, shallow thrust fault flattening at depth between 5 and 15 km and connecting to a mid-crustal, steeper thrust. We suggest that present-day convergence across the Himalaya is mostly accommodated by this fault—no significant motion on smaller thrust faults is required. Furthermore, given that the Gorkha earthquake caused the high Himalayan mountains to subside and that our fault geometry explains measured interseismic displacements, we propose that growth of Himalayan topography may largely occur during the ongoing post-seismic phase. How Himalayan topography is built is unclear. Analysis of surface displacement during the 2015 Gorkha earthquake suggests that large earthquakes may lower the high Himalayan mountains, and topography may grow during the interseismic phase.