| Popis: |
Ever since the last glacial maxima, the snow and ice fields are on a decline. The glaciers all over the Himalayas are on a continuous retreat, diminishing both in their shape and size and in their stored water content. The large glaciers have reduced in size while the smaller ones are either on the “verge of extinction” or have already melted off. In this glooming scenario of global warming, an altogether new phenomenon of “surging glacier” has been monitored in Shyok valley of Karakoram Himalayas in the N-E extremity of J&K state in India. Four groups of glaciers namely the Rimo group, Chong Kumdan, Kichik Kumdan and Aqtash glaciers on the right bank of Shyok river have been studied. These were last studied more than half-a-century ago as reported by Raina and Srivastava (Glacier Atlas of India 51–58, 2008), and no new data has been generated since then. In the present exercise, in addition to Survey of India topographical sheets surveyed in 1975, multi-date, high-resolution satellite data pertaining to each year from 1990 to 2009 have been visually and digitally analyzed as reported by Luckman et al. (Remote Sens Environ 111:172–181, 2007). The actual configuration of each of these compound glaciers have been delineated and then superimposed using the GIS framework to monitor the temporal variations in frontal parts of these glaciers. These four glaciers show some sort of cyclicity in their behavior independent of each other. Each of these glaciers advance for a couple of years, remain standstill for some time and then retreat back for another couple of years before reverting to their advancing position. This cyclicity of advance and retreat is continuing and perhaps the periodicity of the cyclicity is also well defined for each of these glaciers. |
