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Full-Text Articles in Physical Sciences and Mathematics
Catastrophic Ice Shelf Breakup As The Source Of Heinrich Event Icebergs, Christina L. Hulbe, D. R. Macayeal, George H. Denton, Johan Kleman, Thomas Lowell
Catastrophic Ice Shelf Breakup As The Source Of Heinrich Event Icebergs, Christina L. Hulbe, D. R. Macayeal, George H. Denton, Johan Kleman, Thomas Lowell
Geology Faculty Publications and Presentations
Heinrich layers of the glacial North Atlantic record abrupt widespread iceberg rafting of detrital carbonate and other lithic material at the extreme-cold culminations of Bond climate cycles. Both internal (glaciologic) and external (climate) forcings have been proposed. Here we suggest an explanation for the iceberg release that encompasses external climate forcing on the basis of a new glaciological process recently witnessed along the Antarctic Peninsula: rapid disintegrations of fringing ice shelves induced by climate-controlled meltwater infilling of surface crevasses. We postulate that peripheral ice shelves, formed along the eastern Canadian seaboard during extreme cold conditions, would be vulnerable to sudden …
West Antarctic Ice Stream Discharge Variability: Mechanism, Controls, And Pattern Of Grounding Line Retreat, Christina L. Hulbe, Mark A. Fahnestock
West Antarctic Ice Stream Discharge Variability: Mechanism, Controls, And Pattern Of Grounding Line Retreat, Christina L. Hulbe, Mark A. Fahnestock
Geology Faculty Publications and Presentations
West Antarctic ice streams show pronounced flow variability in their downstream reaches, with changes stranding formerly fast-flowing ice and redirecting discharge. A simple model, in which the temperature gradient in basal ice provides control of fast sliding in the downstream reach, can explain this behavior. Downstream thinning steepens the temperature gradient near the bed, increasing upward heat flow and the tendency toward basal freezing. The basal temperature gradient is steepest and the tendency toward basal freezing the strongest in ice that has experienced the most rapid downstream thinning, that is, the fastest-flowing ice. The most ?successful? rapid outflows are regions …