Accelerated thermokarst formation in the McMurdo Dry Valleys, Antarctica

• Published in: Scientific Reports
• Main Authors: Levy, Joseph S., Fountain, Andrew G., Dickson, James L., Head, James W., Okal, Marianne, Marchant, David R., Watters, Jaclyn
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Publishing Group 2013
• Subjects: albedo; Antarc*; Antarctic; Antarctic Peninsula; Antarctica; McMurdo Dry Valleys; Thermokarst
• Online Access: https://doi.org/10.1038/srep02269; https://www.ncbi.nlm.nih.gov/pmc/PMC3721085

Thermokarst is a land surface lowered and disrupted by melting ground ice. Thermokarst is a major driver of landscape change in the Arctic, but has been considered to be a minor process in Antarctica. Here, we use ground-based and airborne LiDAR coupled with timelapse imaging and meteorological data to show that 1) thermokarst formation has accelerated in Garwood Valley, Antarctica; 2) the rate of thermokarst erosion is presently ~ 10 times the average Holocene rate; and 3) the increased rate of thermokarst formation is driven most strongly by increasing insolation and sediment/albedo feedbacks. This suggests that sediment enhancement of insolation-driven melting may act similarly to expected increases in Antarctic air temperature (presently occurring along the Antarctic Peninsula), and may serve as a leading indicator of imminent landscape change in Antarctica that will generate thermokarst landforms similar to those in Arctic periglacial terrains. © 2013 Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareALike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/. Received: 11 April 2013; Accepted: 01 July 2013; Published online: 24 July 2013. This work was supported by the U.S. National Science Foundation (NSF) Antarctic Earth Sciences program under award ANT-1343835 to Levy, Fountain, and W. B. Lyons. Many thanks go to the extensive team that made this research possible, notably, to Dustin Black for bringing the Garwood Valley ice cliff to the attention of the research team, and to all the PHI pilots and ground staff for providing reliable and safe access to the site; to Thomas Nylen, Hasan Basagic, Rickard Pettersson, and James Jerome Bethune for field assistance; to Deb Leslie for stable isotope analyses of ice samples; to the Arizona Accelerator Mass Spectrometry (AMS) Laboratory for radiocarbon dating services; and to Paul Morin and the Polar Geospatial Center for access to satellite image ...