Microstructures in a shear margin: Jarvis Glacier, Alaska

Abstract Microstructures, including crystallographic fabric, within the margin of streaming ice can exert strong control on flow dynamics. To characterize a natural setting, we retrieved three cores, two which reached bed, from flank Jarvis Glacier, eastern Alaska Range, Alaska. The core sites lie ~1 km downstream source, with abundant water present in extracted cores and at base glacier. All exhibit dipping layers, combination debris bands bubble-free domains. Grain sizes coarsen average approaching lateral margin. Crystallographic orientations are more clustered c -axes closer to horizontal nearer measured fabric is sufficiently weak induce little mechanical anisotropy, but data suggest that despite challenging conditions warm ice, short distance, many aspects microstructure, measurable evolved systematic ways.