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Quantification of Thermokarst and Carbon Release: Field Surveys
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Iwahana, University of Alaska Fairbanks, giwahana@alaska.edu
(Presenter)
Permafrost degradation includes the mobilization of water, melting of ground ice and release of greenhouse gases and organic carbon that had once been stored on regional scales. It is of great scientific interest and social concern to know where and to what extent permafrost degradation may occur, especially in ice-rich permafrost land where subsidence by thaw (thermokarst) will cause large changes in surface ecology, landscape evolution and hydrological processes and will also affect human life and subsistence. Lack of knowledge about the fate of permafrost and the amount of carbon release represents a major source of uncertainty for future climate projection. In order to improve the qualification of thermokarst development and to establish a new approach to monitoring carbon release upon permafrost thaw we proposed multiple remote sensing techniques and field observations together with detailed permafrost sample analysis. During the thawing season in 2017 we conducted field surveys in four areas in Alaska including the Anaktuvuk River Fire scar, North Dalton Highway, coastal land near Utqiagvik (Barrow) and Kougarok in the Seward Peninsula. These areas cover various ages and spatial extent of permafrost with a wide range of ice contents. Our fieldwork was designed to obtain surface frozen soil cores and acquire datasets of thaw depth, ground micro-topography and surface moisture along newly established survey transects at each site to validate surface subsidence due to thermokarst by airborne and spaceborne RADAR remote sensing. In this presentation I will give an overview about our 2017 fieldwork and future plans including our preliminary results regarding the spatial variations in seasonal surface displacement (thaw settlement). Associated Project(s): Poster Location ID: 65 Session Assigned: Permafrost and Hydrology
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