Persistent tracers of historic ice flow in glacial stratigraphy near Kamb Ice Stream, West Antarctica

• Published in: The Cryosphere
• Main Authors: N. Holschuh, K. Christianson, H. Conway, R. W. Jacobel, B. C. Welch
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2018
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Ross Sea; West Antarctica; Kamb Ice Stream; Antarc*; Antarctica; Ice Sheet; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-12-2821-2018; https://doaj.org/article/6dbcc7c1f90c4d4f8e59ae779fd54739

Variations in properties controlling ice flow (e.g., topography, accumulation rate, basal friction) are recorded by structures in glacial stratigraphy. When anomalies that disturb the stratigraphy are fixed in space, the structures they produce advect away from the source and can be used to trace flow pathways and reconstruct ice-flow patterns of the past. Here we provide an example of one of these persistent tracers: a prominent unconformity in the glacial layering that originates at Mt. Resnik, part of a subglacial volcanic complex near Kamb Ice Stream in central West Antarctica. The unconformity records a change in the regional thinning behavior seemingly coincident ( ∼ 3440±117 a) with stabilization of grounding-line retreat in the Ross Sea Embayment. We argue that this feature records both the flow and thinning history far upstream of the Ross Sea grounding line, indicating a limited influence of observed ice-stream stagnation cycles on large-scale ice-sheet routing over the last ∼ 5700 years.