Atmospheric and oceanic warming over the past century have driven rapid glacier thinning and retreat, destabilizing hillslopes and increasing the frequency of landslides. The impact of these landslides on glacier dynamics and resultant secondary landslide hazards are not fully understood. We investigated how a 262 ± 77 × 106 m3 landslide affected the flow of Amalia Glacier, Chilean Patagonia. Despite being one of the largest recorded landslides in a glaciated region, it emplaced little debris onto the glacier surface. Instead, it left a series of landslideperpendicular ridges, landslide-parallel fractures, and an apron of ice debris—with blocks as much as 25 m across. Our observations suggest that a deep-seated failure of the mountainside impacted the glacier flank, propagating brittle deformation through the ice and emplacing the bulk of the rock mass below the glacier. The landslide triggered a brief downglacier acceleration of Amalia Glacier followed by a slowdown of as much as 60% of the pre-landslide speed and increased suspended-sediment concentrations in the fjord. These results highlight that landslides may induce widespread and long-lasting disruptions to glacier dynamics.
Bibliographical noteFunding Information:
Van Wyk de Vries has been supported by the University of Minnesota College of Science and Engineering and a Doctoral Dissertation Fellowship. This work is supported by U.S. National Science Foundation grant EAR-1714614 to Wickert, E. Ito, and A. Noren, and lead Principal Investigator M.B. Magnani. Imagery was provided by the European Space Agency (proposal N57129). Reviews by K. Cuffey, F. Beaud, and M. Truffer guided revisions that improved the quality of the manuscript, the focus of our modeling, and our placement of this event in its scientific context.
© 2022. The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license.