Accelerated Thermokarst Formation in the McMurdo Dry Valleys, Antarctica

• Main Authors: Levy, Joseph S., Fountain, Andrew G., Dickson, James L., Head, James W., Okal, Marianne, Marchant, David R., Watters, Jaclyn
• Format: Text
• Language: unknown
• Published: PDXScholar 2013
• Subjects: Thermokarst > Growth > Antarctica > McMurdo Dry Valleys; Glacier caves; Landscape changes > Antarctica; Glaciers > Climatic factors > Arctic regions; Environmental Indicators and Impact Assessment; Glaciology; Soil Science; Antarctic; Antarctic Peninsula; Arctic; Garwood; Garwood Valley; McMurdo Dry Valleys; The Antarctic; albedo; Antarc*; Antarctica; Thermokarst
• Online Access: https://pdxscholar.library.pdx.edu/geology_fac/40; https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1040&context=geology_fac

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.