RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 10, ES5002, doi:10.2205/2008ES000303, 2008

6. Spatial Analysis of Relationship Between Strong Earthquakes With M≥6 and Digital Elevation Model

2008ES000303-fig07
Figure 7
[34]  Digital elevation model of the region under study and strong earthquakes M>6.0 are represented at Figure 1. We can suggest that Himalayan seismicity is mostly correlated with heterogeneities of Earth crust, which are manifested by Earth surface relief. Taking into account this hypothesis we calculated root mean square (RMS) of the Earth surface elevations with moving window R =15 km (Figure 7). We can see that the most of Himalayan earthquakes with M>6.0 are located in zone with RMS > 500 m.

[35]  This is the zone where Himalayan mid-crustal ramp under the southern Higher Himalaya has been proposed on the basis of various geophysical studies [Gahalaut and Kalpna, 2001; Yeats and Thakur, 1998]. Throughout Himalaya and mainly in NW Himalaya, a narrow belt between Higher and Lesser Himalaya shows intense seismic activity, the region is close to ramp and better known as Himalayan Seismic Belt (HSB). Yeats and Thakur, [1998] has given a fault-bend fold model where the megathrust drives southward and upward over the ramp and the axial surface of the fold is active at crustal sacle only. The central Himalaya moves southward as a fault bend fold due to slip by earthquakes that nucleate the detachment under Himalaya of this region. That study also shows maximum relief over the structural ramp indicating a high uplift rates over the ramp. Therefore a high uplift rates in the central Himalaya above the frontal ramp is due to thrust movement during megathrust earthquakes identified by recent compiled seismic catalogue.


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Citation: Gitis, V., E. Yurkov, B. Arora, S. Chabak, N. Kumar, and P. Baidya (2008), Analysis of seismicity in North India, Russ. J. Earth Sci., 10, ES5002, doi:10.2205/2008ES000303.

Copyright 2008 by the Russian Journal of Earth Sciences

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