An assessment of surge-induced crevassing and the formation of crevasse squeeze ridges

Evidence for extensive crevassing is preserved on the deglaciated forelands of many surging glaciers as crevasse squeeze ridges (CSRs). At some point these crevasses make direct connection with the bed in order to become sediment filled, and full-depth connections have been inferred from turbid water up-wellings in crevasses and the formation of concertina eskers. The dynamics of seven surging glaciers are assessed, using a linear elastic fracture mechanics approach, to determine the likely directions of fracture and controlling parameters for Mode I crevasses. Extensional surface strain rates are insufficient to promote top-down full-depth penetration. For small crevasse spacing (