Abstract
AbstractThermal erosion is a major mechanism of permafrost degradation, resulting in characteristic landforms. We inventory thermo‐erosional valleys in ice‐rich coastal lowlands adjacent to the Siberian Laptev Sea based on remote sensing, Geographic Information System (GIS), and field investigations for a first regional assessment of their spatial distribution and characteristics. Three study areas with similar geological (Yedoma Ice Complex) but diverse geomorphological conditions vary in valley areal extent, incision depth, and branching geometry. The most extensive valley networks are incised deeply (up to 35 m) into the broad inclined lowland around Mamontov Klyk. The flat, low‐lying plain forming the Buor Khaya Peninsula is more degraded by thermokarst and characterized by long valleys of lower depth with short tributaries. Small, isolated Yedoma Ice Complex remnants in the Lena River Delta predominantly exhibit shorter but deep valleys. Based on these hydrographical network and topography assessments, we discuss geomorphological and hydrological connections to erosion processes. Relative catchment size along with regional slope interact with other Holocene relief‐forming processes such as thermokarst and neotectonics. Our findings suggest that thermo‐erosional valleys are prominent, hitherto overlooked permafrost degradation landforms that add to impacts on biogeochemical cycling, sediment transport, and hydrology in the degrading Siberian Yedoma Ice Complex.
Highlights
Climate warming in the Arctic is occurring at a much faster rate than the global average,[1] impacting polar permafrost regions
The specific objectives of this study are: (a) to describe the morphometry and spatial distribution of thermo-erosional valleys across three Laptev Sea coastal lowland regions based on remote sensing, geoinformation, and field data; and (b) to relate the identified spatial patterns and morphologies to the topographical and cryolithological settings of the study areas and their evolution through the Holocene
This study focuses on three sites bordering the Siberian Laptev Sea coast (Figure 1)
Summary
Climate warming in the Arctic is occurring at a much faster rate than the global average,[1] impacting polar permafrost regions. Permafrost warming and erosion of permafrost deposits have been reported throughout the northern high latitudes.[2,3,4] Thermokarst and thermal erosion are two major processes of ice-rich permafrost degradation in periglacial landscapes They result in thawing of permafrost-stored organic carbon, which can decompose and be released to the atmosphere and the hydrological system.[5,6,7,8] Landscapes affected by thermokarst and thermal erosion are estimated to contain 330 Pg carbon in the upper 3 m subsurface, constituting 30% of the total 0–3 m permafrost region soil organic carbon storage (1,073 Pg C), highlighting their importance for the global carbon cycle in a rapidly warming Arctic.[9,10] The two processes may substantially alter the water and energy balances of affected regions.[11,12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
