Contrasting sub-ice shelf, sub glacial and glacial marine deposition: Implications for ice shelf stability

• Main Authors: Boyd, L. W., Bartek, L. R., Luyendyk, B. P., Wilson, D.
• Format: Text
• Language: unknown
• Published: DigitalCommons@University of Nebraska - Lincoln 2007
• Subjects: Environmental Indicators and Impact Assessment; Ross Sea; Ross Ice Shelf; Ice Shelf
• Online Access: https://digitalcommons.unl.edu/andrillaffiliates/10; https://digitalcommons.unl.edu/context/andrillaffiliates/article/1009/viewcontent/Luyendyk_AAKCW_2007_Contrasting_sub_ice.pdf

Data from cores collected from sites that were beneath the Ross Ice Shelf until 2000 and 2002 indicate that sub-ice shelf lithofacies are distinguishable from sub-glacial and glacial marine facies. Glacial marine sediment is characterized by diatom-rich, low-density, olive-green, sandy-muds, whereas sub-ice shelf sediment is defined by a lack of diatoms and muds that are enriched in silt and fine sand. Sub-glacial sediment is composed of diatom-poor, high density, coarse grained sandy-mud, rich in fine to coarse sized pebbles. Repetitive, fining-up packages, composed of fine-sand/silty-mud (distal sub ice-shelf deposits), grading into coarse pebbly-mud (sub ice-shelf proximal to the grounding line), suggest cyclicity in the movement of the grounding line over the last 11,000 yrs in the eastern Ross Sea. This research may facilitate a new understanding of ice-shelf dynamics, and possibly refine the current models for the Ross Ice Shelf’s recent glacial history.