The Flow Regime of Ice Stream C and Hypotheses Concerning Its Recent Stagnation

摘要: The downglacier part of ice stream C, West Antarctica largely stagnated over the last few centuries, while upglacier regions continue to flow vigorously. We summarize hypotheses for explaining this behavior and suggest that stagnation is due a combination water-diversion, thermal processes at bed, sticky spots. Stagnation likely occurred near Siple Dome before entirety slowed. Numerous data sets show slow-moving restrained by small, localized basal “sticky spots”. spots are separated extensive soft till containing high-pressure liquid water. Near transition from fast-moving well-lubricated slowmoving ice, hydrologic potential map indicates water flowing in catchment diverted away B. This diversion could have been caused flattening surface slope time response headward growth C drawing down inland ice. Previous mass-balance estimates indicate combined B-C drainage most thinning slowly, similar rest Coast, consistent with continuing lubricate fast flow, but now concentrated