Glacial surges are short-lived events where a glacier can advance substantially, moving at velocities up to 100 times faster than normal. Surging glaciers cluster around a few areas. High concentrations of surging glaciers occur in Svalbard, the Canadian Arctic islands, Alaska and Iceland. In some glaciers, surges can occur in fairly regular cycles, with 15 to 100 or more surge events per year. In other glaciers, surging remains unpredictable.[1] In some glaciers, however, the period of stagnation and build-up between two surges typically lasts 10 to 200 years and is called the quiescent phase.[2] During this period the velocities of the glacier are significantly lower, and the glaciers can retreat substantially

https://en.wikipedia.org/wiki/Surge_(glacier)

The calving glacier Aavatsmarkbreen in Forlandsundet. Photo: Heïdi Sevestre/UNIS

https://www.unis.no/solving-the-mystery-of-surging-glaciers/

Glaciers of all shapes, sizes, and longitudinal profiles can surge, and no unusual "ice dams" or bedrock constrictions are evident. Surges occur in many different climatic, tectonic, and geologic environments, but only in certain limited areas (mainly in the Alaska, eastern Wrangell, and St. Elias mountains). Three types of surging glaciers are defined: (I) large to moderate-sized glaciers with large displacements and very fast flow, (II) large to moderate glaciers with moderate displacements and flow rates, and (III) small glaciers with small displacements and moderate to fast flow rates. All three types involve an inherent instability which is self-triggered at regular intervals, but with Type I surges an additional (unknown) mechanism produces the very high flow rates.

http://www.nrcresearchpress.com/doi/abs/10.1139/e69-081?journalCode=cjes#.XEWVUVxKjcs