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Shri Ashtapad Maha Tirth - II
moraines at 3600 m asl indicates a huge glacier expansion during 250-900 AD, when the Zelongnong Glacier tongue reached down valley to the Yarlung Tsangpo River and blocked the river valley (Chinese Academy of Sciences, 1996). Gyalaperi Glacier (13) is a large valley glacier just north of the Yarlung Tsangpo River gorge. It reaches about 800 m below the alpine tree limit. According to the maximum tree ages on the lateral moraine of Gyalaperi Glacier, the maximum ice margin extent of this glacier during the LIA was reached at about 1760-1780 AD, and smaller advances occurred in 1951 and 1987 AD (Brauning, 2006). In the central Himalayas, Li et al. (1983, 1986) determined glacier advances in the Paohanli Mountains by lichenometry. Estimated lichen ages suggest terminations of glacier advances of Mount Paohanli (14), Qubixiarna Glaciers (15) and Woguodulin (16) in 1818, 1875 and 1885 AD, respectively. On the basis of CRN dating, glacier advances around 1000 AD and the 18-19th centuries were recognized in the Garhwal Himalaya (Barnard et al., 2004b; Sharma and Owen, 1996).
2.5 Southern Himalayan Mountains Here we confine the southern Himalayan Mountains (17-21) to the region extending between 27°54'-28°38' N, 84°-87°E where annual precipitation is dominated by the south Asian summer monsoon. The ELAs of the glaciers in this region vary between 5000 and 5600 m asl, and the glaciers belong to the monsoonal temperate type or to a cold high-alpine type (submaritime type according to Ageta and Kadota, 1992). In the Khumbu Himal, the mean monthly temperatures during the summer months are about 3 °C at 5000 m asl (Benn and Owen, 1998; Owen and Benn, 2005). Rothlisberger and Geyh (1985) developed a generalized curve of Holocene glacier fluctuations in the Himalayas/Kara-koram based on 14C dating (mainly from the Himalayas, including the Khumbu Himal and Annapurna region of exposed fossil soils in lateral moraines. The details for the dated material, sampling locations, and the studied glaciers were described by Rothlisberger and Geyh (1985) and Rothlisberger (1986). Lami et al. (1998) calibrated the 14C dates and synthesized a chronology of glacial retreats and advances. During the last 2000 years, several glacier advances can be identified during the periods 380-600 AD, 870-1100 AD, 1250 AD, 1400-1430 AD and 1550-1850 AD. Since 1860 AD, there has been an overall retreat of almost all glaciers with limited fluctuations. Evidence from moraine OSL (Richards et al., 2000b) and CRN dates (Finkel et al., 2003) in the Khumbu Himal region confirms a glacier advance around 1000 AD. 3.0 Regional glacier variations during the last two millennia We compiled all available evidence for glacier advances in various parts of the monsoonal temperate glacier area during the last two millennia, including 14C dates derived from buried trunks in moraines and from paleosols between moraines, maximum ages of trees growing on moraines, extreme growth reductions in ring-width series, and estimated lichen dates on moraines. At least three clear periods of glacier advance can be identified (Fig. 2): around 200-600 AD, 800-1150 AD and during 1400-1920 AD. The glacier advance around 200-600 AD was the most widespread advance of monsoonal temperate glaciers and occurred in the Hengduan
Late Holocene monsoonal temperate glacier Fluctuations...
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