Climatic Significance of Isotopic and Geochemical Signatures in Snow and Ice from Glaciers of Garhwal Himalaya India

Abstract

The Himalayan region has the largest concentration of glaciers outside the polar region in spite of its proximity to the tropics and is the source of several large perennial rivers like Ganga, Indus, Brahmaputra, Yangtze, Mekong, Salween, Red River (Asia), Xinjiang, Chao Phraya, Irrawaddy, Amu Darya, Syr Darya, Tarim and Yellow Rivers which are the lifeline of the people of Asia. Therefore it is aptly called as The Third Pole or the Water Tower of Asia . The combined drainage basin is home to some 1.3 newlinebillion people, providing about 8.6 x 106 m3 of water annually to fulfill the needs of the region. newlineIn India, the glaciers are restricted to the Extra Peninsular area, i.e., the newlineHimalaya within the latitude 27°N to 36°N and longitude 72°E to 96°E, comprising the newlineterritories of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim and newlineArunachal Pradesh. The Geological Survey of India has estimated about 9,575 Glaciers in the Indian Himalaya, with total glacier cover of approximately 40,000 km2 and ice volume of the order of about 2,000 km3. Two major river basins originate in the region namely the Indus and the Ganga. The Indus basin has the largest number of glaciers ~7,997, whereas the Ganga basin holds ~1,578 glaciers. newlineA systematic geochemical study on seasonal variation of major ions has been newlineundertaken to get an insight into the source of dissolved ions as well as chemical weathering processes controlling the glacial meltwater of the Dokriani Glacier near the snout. For the present study, samples of meltwater were collected during the study newlineperiod. Calcium (Ca+2) and magnesium (Mg) are the two major cations whereas sulfate newline(SO4 -2) is the leading anion followed by bicarbonate (HCO3 -) in the meltwater. The newlinecontribution of high ratios of Ca+2+Mg+2)/(Na++ K+), Ca+2/Na+, Mg/Na+, HCO3/Na+ v Ph.D. Thesis, Akshaya Verma, Doon University © and low ratio of (Na++ K+)/TZ+ for pre-monsoon and post-monsoon seasons suggests the predominance of weathering of carbonate minerals which is the major source of dissolve.