A moraine dammed lake burst is a dangerous threat of GLOF in Nepal. Moraine dam materials are solely the debris consisting of large boulders, gravels, sand, silt, clay and dead glacier ice. Hence a lake formed by a moraine is usually a quite unstable condition. A moraine dammed glacier lake could burst in two ways a. a. dam breaks due to some external effects and b. Self-destruction due to the aging of moraine dam A. External triggers for a lake burst. Water in lakes overtopping carries a sufficient energy\to break a moraine dam easily. Once a beach is created on a moraine dam it leads to positive feedback for lake outburst running water excavates sand and erodes the breach wider and deeper which brings about further increase in the release of running water the over topping of lake water is caused by a big wave which us generated by a huge mass falling down in a lack such as snow or glacier avalanche from the steep slopes beside the lake and also advancing , sliding, and calving of he mother glacier into lake. Earthquake is an external trigger contributing to a lake burst. b. Self destruction of a moraine dam The self destruction of a moraine dam is also caused by the spontaneous failure of the well weathered dam slope and leakage from the networks of drainage conduits developed in dam. The dam break is closely correlated with the water level of the dam. The dam break is closely related with water level of the dam. The shape and size of the conuduits may change from season to season and year to year being frozen / diapered in the winter and being reopened during summer. Also a small conduit occasionally grows to a large conduit due to erosion by water. These drainage conduits tend to weaken the dam as a whole whereby the dam collapses spontaneously due to water pressure without particular triggering action.

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