Morainal bank progradation and sediment accumulation in Disenchantment Bay, Alaska: Response to advancing Hubbard Glacier

Advancing glaciers can stabilize their termini through the formation of morainal banks, which act as sediment barriers that compensate for changes in water depth at the grounding line. A study of Hubbard Glacier in Alaska's Disenchantment Bay revealed that between 1978 and 2010, both the ice face and morainal bank advanced at an average rate of approximately 34 meters per year, with spatial and temporal variations ranging from 14 to 80 meters per year. This advance was linked to cyclical deposition and gravitational erosion on the proximal slope of the morainal bank, as well as possible ice pushing in areas without recent sedimentation. The study also found that sedimentation rates in the deep basin increased from 0.88 meters per year (1978–1999) to 1.22 meters per year thereafter, suggesting a combined response to glacier advance and sediment dispersal, as well as increased sediment yield from other sources. The research highlights the stabilizing role of morainal banks in advancing marine-terminating glaciers into deep-water fjords.

Goff, J. A., Lawson, D. E., Willems, B. A., Davis, M., & Gulick, S. P. S. (2012). Morainal bank progradation and sediment accumulation in Disenchantment Bay, Alaska: Response to advancing Hubbard Glacier. Journal of Geophysical Research: Earth Surface, 117(F2). Portico. https://doi.org/10.1029/2011jf002312