TY - JOUR T1 - Sediment controls dynamic behavior of a Cordilleran Ice Stream at the Last Glacial Maximum A1 - Cowan,Ellen A. A1 - Zellers,Sarah D. A1 - Müller,Juliane A1 - Walczak,Maureen H. A1 - Worthington,Lindsay L. A1 - Caissie,Beth E. A1 - Clary,Wesley A. A1 - Jaeger,John M. A1 - Gulick,Sean P. S. A1 - Pratt,Jacob W. A1 - Mix,Alan C. A1 - Fallon,Stewart J. AD - Department of Geological and Environmental Sciences, Appalachian State University, Box 32067, Boone, NC, 28608, USA AD - School of Geoscience, Physics, and Safety, University of Central Missouri, Warrensburg, MO, 64093, USA AD - Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Alten Hafen 26, 27568, Bremerhaven, Germany AD - Center for Marine Environmental Sciences, University of Bremen/MARUM, 28359, Bremen, Germany AD - College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, 97331, USA AD - Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM, 87131, USA AD - Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, 50011, USA AD - Department of Geological Sciences, University of Florida, Gainesville, FL, 32611, USA AD - Institute for Geophysics & Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, 78758, USA AD - Research School of Earth Science, The Australian National University, Canberra, ACT, 2601, Australia UR - https://archimer.ifremer.fr/doc/00694/80603/ DO - 10.1038/s41467-020-15579-0 N2 - The uncertain response of marine terminating outlet glaciers to climate change at time scales beyond short-term observation limits models of future sea level rise. At temperate tidewater margins, abundant subglacial meltwater forms morainal banks (marine shoals) or ice-contact deltas that reduce water depth, stabilizing grounding lines and slowing or reversing glacial retreat. Here we present a radiocarbon-dated record from Integrated Ocean Drilling Program (IODP) Site U1421 that tracks the terminus of the largest Alaskan Cordilleran Ice Sheet outlet glacier during Last Glacial Maximum climate transitions. Sedimentation rates, ice-rafted debris, and microfossil and biogeochemical proxies, show repeated abrupt collapses and slow advances typical of the tidewater glacier cycle observed in modern systems. When global sea level rise exceeded the local rate of bank building, the cycle of readvances stopped leading to irreversible retreat. These results support theory that suggests sediment dynamics can control tidewater terminus position on an open shelf under temperate conditions delaying climate-driven retreat. Y1 - 2020/04 PB - Springer Science and Business Media LLC JF - Nature Communications SN - 2041-1723 VL - 11 IS - 1 ID - 80603 ER -