Repeat terrestrial LiDAR for permafrost thaw subsidence change detection in North Alaska

• Main Authors: Günther, Frank, Grosse, Guido, Ulrich, Mathias, Nitze, Ingmar, Fuchs, Matthias, Jones, Benjamin
• Other Authors: Deline, Philip, Bodin, Xavier, Ravanel, Ludovic
• Format: Conference Object
• Language: unknown
• Published: Laboratoire EDYTEM - UMR5204, Université Savoie Mont Blanc, Bâtiment «Pôle Montagne» 2018
• Subjects: Active layer thickness; Ice; north slope; permafrost; Tundra; wedge*; Alaska
• Online Access: https://epic.awi.de/id/eprint/47574/; https://epic.awi.de/id/eprint/47574/1/EUCOP5_2018_Book_of_abstracts_569-570.pdf; https://hal.archives-ouvertes.fr/hal-01816115/document; https://hdl.handle.net/10013/epic.61e2fda3-2306-4b02-9971-764ae38ca226

The distinguishing feature of permafrost in the Arctic is the presence of a large amount of ice below the earth surface. Thermal degradation and subsequent destabilization of ground ice rich terrain cause thaw subsidence. Because these phenomena are hard to detect, they have received not much attention, despite their potentially global significance through the permafrost carbon feedback and implications for active layer thickness monitoring. Clearly, however, detailed local inventories are required to calibrate regional targeted long and short-term assessments for measuring surface deformation due to permafrost thaw. We analyze time series of repeat terrestrial laser scanning (rLiDAR) for quantification of land surface lowering on a tundra upland in the Teshekpuk Lake Special Area on Alaska´s North Slope. Here, considerable negative surface elevation changes have been detected over two years from 2015 to 2017. Spatial patterns of land elevation changes indicate that ice wedge polygon troughs are particularly prone to subsidence. This highlights the vulnerability of arctic tundra lowlands with ice-rich permafrost close to the surface.