A Close Observation to a Typical Continental Valley Glacier Surge in Northeastern Pamir

Abstract. In May 2015, it is reported that "a glacier slid 20 km long, accompanying with disappearance of ~ 10 km2 grasslands on the north slope of Mt Jiubie, Kongur Mountain, northeastern Pamir, China". Based on expedition and multi-temporal RS image interpretation, this paper confirms that it was a rare continental valley glacier surge occurred in the tributaries of Kalayayilake Glacier, and find: (1) It has significant phenomena difference between quiescent and surging phase, including distorted medial moraine ridge, extruding-bulging ice masses, disappeared superglacial lakes etc; (2) Compared with the oceanic glacier surge, its characteristics are higher ice choking uplift and large chaotic crevasses area extent, but having relatively small integral movement distance with low velocity; (3) Environmental factors of large glacier coefficient, long tongue, low altitude, especially the stagnant downstream tongue and thick superglacial moraine, contribute to continental glacier surge's features, and the long-term temperature rise and rainfall enhancement in study area seem to be consistent with the occurrence of this surge; (4) This surge brings out severe strength reduction of glacier, rapid ablation of ice, congestion in the subglacial passageway, and accumulation of englacial water, which together have being bred the risk of terminus advance suddenly to result in flooding and debris flow.