QUATERNARY HISTORY OF GLACIER MORPHOLOGY AND LANDFORM DEVELOPMENT IN THE GARHWAL AND LAHUL HIMALAYA

The timing and extent of Lateglacial and Holocene glacial fluctuations in the Himalaya of Northern India is not well defined because of the lack for detailed mapping and dating of glacial successions. Chronostratigraphies were developed using Be-10 terrestrial cosmogenic nuclide (TCN) surface exposure dating, field mapping and remote sensing using repeat ASTER imagery to improve knowledge of the latest Quaternary glaciation in Northern India. Detailed studies focused on the Bhillangana and Mandakini valleys in the monsoon-influenced Garhwal Himalaya and the semi-arid Milang valley in the Lahul Himalaya. Each valley has an impressive succession of moraines reflecting significant Lateglacial, early Holocene and Neoglacial glacial advances. Equilibrium-line altitudes (ELAs) were reconstructed for each glacial advance using several methods (e.g. AAR, THAR, MELM) to quantify and compare the degree of glaciation. ELAs show strong contrasts between regions reflecting the major climatic gradient that exists across the Himalaya of Northern India. Quantifying such changes in glacial extents on longer timescales (thousands of years) and short timescales (years to decades) are important for understanding regional climate and hydrological changes.