Quantifying wedge-ice volumes in yedoma and thermokarst basin deposits

• Published in: Permafrost and Periglacial Processes
• Main Authors: Ulrich, Mathias, Grosse, Guido, Strauss, Jens, Schirrmeister, Lutz
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: JOHN WILEY & SONS LTD 2014
• Subjects: Ice; permafrost; Permafrost and Periglacial Processes; Thermokarst; wedge*; Alaska; Siberia
• Online Access: https://epic.awi.de/id/eprint/35710/; https://epic.awi.de/id/eprint/35710/1/Abstract_Quantifying_Wedge_Ice.pdf; http://onlinelibrary.wiley.com/doi/10.1002/ppp.1810/abstract; https://hdl.handle.net/10013/epic.43642; https://hdl.handle.net/10013/epic.43642.d001

Wedge-ice volume (WIV) is a key factor in assessing the response of ice-rich permafrost landscapes to thaw and in quantifying deep permafrost soil carbon inventories. Here, we present a method for calculating WIV in late Pleistocene Yedoma deposits and Holocene thermokarst basin deposits at four study areas in Siberia and Alaska. Ice-wedge polygons and thermokarst mound (baydzherakh) patterns were mapped on different landscape units using very high-resolution (0.5 m/pixel) satellite imagery (WorldView-1 and GeoEye-1). In a geographic information system (GIS) environment, Thiessen polygons were automatically created to reconstruct relict ice-wedge polygonal networks, and field and published data on ice-wedge dimensions were used to generate three-dimensional subsurface models that distinguish between epi- and syngenetic ice-wedge geometry. The results reveal significant variations in WIV between the study sites and within certain terrain units. Calculated maximum WIV ranges from 31.4 to 63.2 vol% for Yedoma deposits and from 6.6 to 13.2 vol% for thermokarst basin deposits.