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The gravity response and crustal shortening in the Himalayan belt are modeled in detail for the first time in the NW Himalaya. The Bouguer gravity anomaly along a *450-km-long (projected) transect from the Sub-Himalaya in the south to the Karakoram fault in the north across the Indus-Tsangpo Suture Zone is modeled using spectral analysis, wavelet transform and forward modeling. The spectral analysis suggests three-layer interfaces in the lithosphere at 68-, 34-and 11-km depths corresponding to the Moho, the Conrad discontinuity and the Himalayan decollement thrust, respectively. The coherence, admittance and cross spectra suggest crustal shortening because of convergence compensated by lithospheric folding at 536-and 178-km wavelength at the Moho and the upper-crustal level. An average effective elastic thickness of around 31 km is calculated using the coherence method. The gravity data are modeled to demarcate intracrustal to subcrustal regional thrust/fault zones. The geometrical constraints of these faults are obtained in the space scale domain using the wavelet transform, showing good correlation with the major tectonic boundaries. The crustal configuration along the transect shows how the Moho depth increases from 45 to 80 km towards the north with the locus of flexure of the Indian crust beneath the Higher Himalayan zone. The combination of forward modeling and wavelet analysis gives insight into the subsurface extent and geometry of regional structures across the NW Himalaya.

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Transient deformation events observed in Global Positioning System (GPS) data from the Basin and Range extensional province may illuminate qualitatively similar transient events observed in subduction zones and other tectonic environments. We model GPS time series at 22 sites using a combination of hyperbolic tangent function analysis and elastic load deformation estimated from climatological data. We identify two transient events,~2000.4 and~2004.4, with roughly similar timing and displacement to those described previously by other researchers. The first few years of GPS observations, adopted as a reference state in earlier studies, are found to be anomalous. Our results differ from previous studies in two respects. First, a significant component of northward transient motion occurs during both events, despite a reversal of sign in east component motion. Second, sites move coherently in the eastern as well as the western Basin and Range. Surface mass loading, the largest source of transient stress forcing in the region, exhibits no evidence of a simple relationship to the deformation transients. Prior studies inferred slip on a single megadetachment at the Moho, but that hypothesis assumes negligible ductile deformation of the lower crust and a dry olivine rheology for the uppermost mantle. Recent measurements of crustal quartz abundance and effective elastic thickness suggest both assumptions are unlikely. Basin and Range transients can be reconciled with the frictional slip mechanism widely accepted for subduction zone transients provided that slip is occurring on discontiguous detachment surfaces at midcrustal depths.

Abstract. The complexity in the tsunami phenomenon makes the available warning systems not much effective in the practical situations. The problem arises due to the time lapsed in the data transfer, processing and modeling. The modeling and simulation needs the input fault geometry and mechanism of the earthquake. The estimation of these parameters and other aprior information increases the utilized time for making any warning. Here, the wavelet analysis is used to identify the tsunamigenesis of an earthquake. The frequency content of the seismogram in time scale domain is examined using wavelet transform. The energy content in high frequencies is calculated and gives a threshold for tsunami warnings. Only first few minutes of the seismograms of the earthquake events are used for quick estimation. The results for the earthquake events of Andaman Sumatra region and other historic events are promising.