An investigation of the deforming layer/debris-rich basal-ice continuum, illustrated from three Alaskan glaciers

• Published in: Journal of Glaciology
• Main Author: Hart, Jane K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1995
• Subjects: Earth-Surface Processes; Childs Glacier; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000034936; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000034936

Abstract Three small Alaskan glaciers with different bed conditions were studied: Exit Glacier had a thin deforming layer and produced subglacial and proglacial glaciotectonic land forms; Childs Glacier also had a thin deforming layer but the upper part was frozen to the ice; Matanuska Glacier had no deforming layer but had subglacial debris-rich ice. Since it has been shown that sediment at the base can account for the majority of ice movement, it is suggested that there is a deforming bed/debris-rich continuum whereby similar processes occur throughout the different subglacial environments. These include: similar longitudinal deformation patterns (compression at the margin, extension and simple shear up-glacier); similar vertical deformation patterns, increase in deformation (and fabric strength) upwards through the sequence (leading to the attenuation of stratified ice into dispersed ice); and similar and interrelated incorporation processes. The major differences were that the processes occurred at a much faster rate within the deforming layer and that probably only the deforming layer will be recorded in the geological record.