Sentinel-1 InSAR Measurements of Elevation Changes over Yedoma Uplands on Sobo-Sise Island, Lena Delta

Abstract

Yedoma-extremely ice-rich permafrost with massive ice wedges formed during the Late Pleistocene-is vulnerable to thawing and degradation under climate warming. Thawing of ice-rich Yedoma results in lowering of surface elevations. Quantitative knowledge about surface elevation changes helps us to understand the freeze-thaw processes of the active layer and the potential degradation of Yedoma deposits. In this study, we use C-band Sentinel-1 InSAR measurements to map the elevation changes over ice-rich Yedoma uplands on Sobo-Sise Island, Lena Delta with frequent revisit observations (as short as six or 12 days). We observe significant seasonal thaw subsidence during summer months and heterogeneous inter-annual elevation changes from 2016-17. We also observe interesting patterns of stronger seasonal thaw subsidence on elevated flat Yedoma uplands by comparing to the surrounding Yedoma slopes. Inter-annual analyses from 2016-17 suggest that our observed positive surface elevation changes are likely caused by the delayed progression of the thaw season in 2017, associated with mean annual air temperature fluctuations.

Seasonal Progression of Ground Displacement Identified with Satellite Radar Interferometry and the Impact of Unusually Warm Conditions on Permafrost at the Yamal Peninsula in 2016

“…The ground heave right after thaw has been also observed by Chen et al [10] for Sentinel-1 and has been attributed to excess snowmelt water percolating into the soil and eventually producing heave of up to 1 cm as observed in situ by Mackay [66].…”

“…Changes in surface moisture are expected to impact the retrieval as the radar signal may penetrate deeper into the soil under dryer conditions, (e.g., [10][11][12]). The found apparent relationship between DDT and subsidence for the dominating landscape type indicates a limited impact on central Yamal.…”

“…A further shortcoming is the lack of in situ measurements of active-layer thickness. Such measurements are often sporadic when related to expeditions and therefore do not allow detailed interpretation of findings from InSAR analyses, (e.g., [10]). Measurement grids of long-term monitoring sites which are part of the Circumpolar Active-Layer Monitoring (CALM) network provide very valuable data in this context.…”

Rapid Fluvio-Thermal Erosion of a Yedoma Permafrost Cliff in the Lena River Delta

“…The delta island Sobo-Sise is characterized by late Pleistocene, ice-rich yedoma Ice Complex deposits with Holocene cover deposits. The yedoma deposits at Sobo-Sise are affected by rapid thaw processes such as thermokarst lake dynamics and thermo-erosional valley formation (Morgenstern et al, 2011;Nitze and Grosse, 2016) as well as thaw subsidence (Chen et al, 2018). Only 19% of the area of Sobo-Sise Island consist of largely un-affected yedoma uplands, whereas the remaining area of the island consists of degraded thermokarst basins (alases) and fluvial deposits (Fuchs et al, 2018).…”

Post‐Wildfire Surface Deformation Near Batagay, Eastern Siberia, Detected by L‐Band and C‐Band InSAR

“…Journal of Geophysical Research: Earth Surface thaw-related landforms in permafrost areas (e.g., Antonova et al, 2018;Chen, Günther et al, 2018;Liu et al, 2014Liu et al, , 2015Liu et al, , 2010Molan et al, 2018;Short et al, 2011;Strozzi et al, 2018). Although subsidence signals as a result of thermokarst associated with Alaskan wildfires have been detected using InSAR (Iwahana, Harada, et al, 2016;Liu et al, 2014;Michaelides et al, 2019;Molan et al, 2018), no such studies have been conducted on Siberian fires, to our knowledge.…”