Fjords as temporary sediment traps: History of glacial erosion and deposition in Muir Inlet, Glacier Bay National Park, southeastern Alaska

Fjords act as temporary sediment traps, significantly influencing glacial erosion and deposition patterns. A study of Muir Inlet, Glacier Bay National Park, revealed two prominent glacial erosion surfaces: one from the Last Glacial Maximum (LGM) and another from the Little Ice Age (LIA). The LGM ice sheet, which was 1700 meters thick in Muir Inlet, eroded bedrock extensively, leaving deposits over 300 meters thick beneath the LIA erosion surface. The study used high-resolution seismic-reflection profiles to model sediment flux, ranging from 1.3 × 10^6 m³/yr to 4.6 × 10^7 m³/yr, increasing logarithmically with drainage basin area. This sediment flux includes contributions from bedrock erosion, persistent tributary glaciers, and LGM sediments stored in deeper basins. The research highlights the importance of sediment gravity flows originating from sills and fjord walls in shaping these landscapes.

Cowan, E. A., Seramur, K. C., Powell, R. D., Willems, B. A., Gulick, S. P. S., & Jaeger, J. M. (2010). Fjords as temporary sediment traps: History of glacial erosion and deposition in Muir Inlet, Glacier Bay National Park, southeastern Alaska. Geological Society of America Bulletin, 122(7-8), 1067–1080. https://doi.org/10.1130/b26595.1