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Himalayan Geology, Vol. 31
(1), 2010, pp. 71-78, Printed in India
Surface morphology, elevation changes and Terminus retreat of Dokriani
Glacier, Garhwal Himalaya: implication for climate change
D.P. DOBHAL, MANISH MEHTA
Wadia Institute of Himalayan Geology, Dehra Dun – 248 001, India
Abstract: The present study deals with morphology, surface lowering
and terminus retreat of Dokriani glacier from 1962 to 2007. Previously, the
glacier boundary was recorded in Survey of India toposheet, which provides
preliminary information of the glacier. Reoccupying the longitudinal
profiles along centerline of glacier drawn from Survey of India maps of 1962
and 1995, and field survey in 2007, with adding surface mass balance data
available for the period enabled to determine the changes in surface
elevation along the centerline of the glacier. A comparison of longitudinal
profiles indicates overall surface changes, substantial thinning at lower
elevation and reduction of the glacier area. Surface elevation changes can
be the result of reduction in accumulation and enhancement of surface
melting. Average reduction of glacial ice thickness by 2.5 ma-1 of water
equivalent is significant, since the glacier has average ice thickness of
65m estimated by Ground Penetrating Radar (GPR) profiling in 1995. The
terminus retreat measurements were made by fixed date observation at the end
of ablation period of each year. The results shows terminus (Snout) retreat
from 1991 to 2007 at an average rate of 15.6m/yr. It was also observed that
the retreating rate of terminus has decreased to 16.6 m/yr (2001-2007) from
17-18 m/yr recorded during 1991-2000.
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