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Glaciers and snowfields can form potential hazards in the Himalayas, and in similarly glacierised regions of the world
. Some glaciological phenomena can have significant impacts upon society over a short time scale (minutes–days), such as ice/snow avalanches and glacial floods. Other related hazards can be equally serious but less obvious when considered on a much longer time scale (months–years–decades), such as glacier volume fluctuations leading to water resource problems. Only when humans and their activities become vulnerable to glacier-related processes is there considered to be a hazard risk. As glaciers recede in response to climatic warming, the number and volume of potentially hazardous moraine-dammed lakes in the Himalayas is increasing. These lakes develop behind unstable ice-cored moraines, and have the potential to burst catastrophically, producing devastating Glacial Lake Outburst Floods (GLOFs). Discharge rates of 30,000 m3 s−1 and run-out distances in excess of 200 km have been recorded. Despite the scale of the risk, it is possible to assess and mitigate hazardous lakes successfully. Hazard assessment using satellite images has been effective for remote areas of Bhutan, and remediation techniques successfully developed in the Peruvian Andes are now being deployed for the first time in Nepal
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This paper presents the first glacial chronology for the Lahul Himalaya, Northern India
. The oldest glaciation, the Chandra Glacial Stage, is represented by glacially eroded benches at altitudes greater than 4300 m above sea-level. This glaciation was probably of a broad valley type. The second glaciation, the Batal Glacial Stage, is represented by highly weathered and dissected lateral moraines, which are present along the Chandra valley and some of its tributaries. This was an extensive valley glaciation. The third major glaciation, the Kulti Glacial Stage, is represented by well-preserved moraines in the main tributary valleys of the Chandra valley. This represents a less extensive valley glaciation. Two minor glacial advances, the Sonapani I and II, are represented by small sharp-crested moraines, which are within a few hundred metres or few kilometres of the present-day glaciers. The change in style and extent of glaciation is attributed to an increase in aridity throughout the Quaternary, due either to global climatic change or uplift of the Pir Panjal mountains to the south of Lahul, which restricted the northward penetration of the south Asian summer monsoon
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