Further Observations on Stress-generated Ice in the Blue Glacier, Washington, U.S.A.

Abstract

A more detailed examination is made of the stress-generated ice crystallization features already discussed by LaChapelle (1968), using mainly thin-section techniques. The crystallization features on the walls of a tunnel within the Blue Glacier are localized at fine-grained layers and are led by liquid water traveling along grain boundaries within the wall and within the deposits themselves. The water filling the crevasse encountered at the end of the tunnel was freezing uniformly to the crevasse walls as well as forming Thomson crystals within the water, and the evidence points to an important role for constitutional super-cooling in the Thomson crystal formation. The forms of most of the Thomson crystals are explainable qualitatively by beat flow effects.