Astronomy and Astrophysics – Astronomy
Scientific paper
Jun 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009geoji.177.1111a&link_type=abstract
Geophysical Journal International, Volume 177, Issue 1, pp. 1111-1120.
Astronomy and Astrophysics
Astronomy
1
Inverse Theory, Body Waves, Seismic Attenuation, Crustal Structure, Asia
Scientific paper
We investigate the seismic attenuation along a 160 km profile from the Lower to the High Himalaya in the Garhwal region, India, through the analysis of Lg waveforms from regional earthquakes recorded on 18 broadband seismographs with interstation spacing of 7-10 km. Lateral variability in attenuation is derived through the inversion of 36 two-station Q0(Lg Q at ~1 Hz) measurements using a global optimization scheme. We observe a contrasting attenuation property in the two Himalayan belts: the Lower Himalaya has Q0 of 742 +/- 235 similar to those observed in the Indian shield, whereas the High Himalaya is characterized by an unusually low Q0 value of 30-60. The seismic attenuation is also well correlated with the P-wave teleseismic traveltime residual pattern: faster arrival (approximately 0.2 s) at stations in the Lower Himalaya as compared to azimuthally independent time delay of ~0.75 s for the High Himalayan stations. The high attenuation and low velocity in the High Himalaya suggests that low viscosity and partial melt in the crust can be correlated to the presence of Miocene leucogranite plutons in this Himalayan belt, a magmatic product of the Indo-Asian collision and presumably evidence of a partial melting event. This shallow low viscosity channel possibly connects the mid-crustal channel beneath Tibet.
Ashish
Gupta Sandeep
Padhi Amit
Rai Sanatan
No associations
LandOfFree
Seismological evidence for shallow crustal melt beneath the Garhwal High Himalaya, India: implications for the Himalayan channel flow does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Seismological evidence for shallow crustal melt beneath the Garhwal High Himalaya, India: implications for the Himalayan channel flow, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seismological evidence for shallow crustal melt beneath the Garhwal High Himalaya, India: implications for the Himalayan channel flow will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1781416