Interseismic strain accumulation on the Himalayan crustal ramp (Nepal)
Article first published online: 7 DEC 2012
Copyright 1995 by the American Geophysical Union.
Geophysical Research Letters
Volume 22, Issue 7, pages 751–754, 1 April 1995
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 10 OCT 1994
- Manuscript Received: 9 SEP 1994
The Departement of Mines and Geology has been monitoring the seismicity of the Central Himalayas of Nepal since 1985. Intense microseismicity and frequent medium-size earthquakes (mL<4) tend to cluster beneath the topographic front of the Higher Himalaya. This 10–20km deep seismicity also correlates with a zone of localized uplift that has been evidenced from geodetic data. Both microseismic and geodetic data indicate strain accumulation on a mid-crustal ramp that had been previously inferred from geological and geophysical evidence. This ramp connects a flat decollement under the Lesser and Sub-Himalaya with a deeper decollement under the Higher Himalaya, and probably acts as a geometric asperity where strain and stress build up during the interseismic period. The large Himalayan earthquakes could nucleate there and probably activate the whole flat-and-ramp system up to the blind thrusts of the Sub-Himalaya.