Estimation of surface ice velocity of Chhota- Shigri glacier using sub-pixel ASTER image correlation.

This article presents results on surface ice velocity of the Chhota-Shigri glacier, Himachal Himalaya, deduced by applying sub-pixel image correlation technique (COSI-Corr software) on the ASTER time series data (2003-2009). The remote sensing-derived measurements are found to match quite well with the field measurements. In general, the surface ice velocity varies from ~20 m/yr to ~40 m/yr. Velocity variations occur in different parts of the glacier and also from year to year. In all the years considered for this glacier, the mid-ablation zone and the accumulation zone exhibit higher velocities and zones near the snout and equilibrium line altitude have relatively lower velocities. Further, the velocities are found to be relatively higher in the years 2005-2006 and 2007-2008 and lower in the years 2006-2007 and 2008-2009. These spatial and temporal variations in velocity, which could be related to the glacier morphology and hydro-metrological factors, need to be further studied. [ABSTRACT FROM AUTHOR]