In recent decades, acceleration of coastal erosion has been observed at many key sites of the Arctic region. Coastal dynamics of both erosional and accretional stretches at Kharasavey, Kara Sea, was studied using multi-temporal remote sensing data covering the period from 1964 to 2022. Cross-proxy analyses of the interplay between coastal dynamics and regional (wave and thermal action) and local (geomorphic and lithological features; technogenic impact) drivers were supported by cluster analysis and wind–wave modelling via the Popov–Sovershaev method and WaveWatch III. Ice-rich permafrost bluffs and accretional sandy beaches exhibited a tendency towards persistent erosion (−1.03 m/yr and −0.42 m/yr, respectively). Shoreline progradation occurred locally near Cape Burunniy (6% of the accretional stretch) and may be due to sediment flux reversals responding to sea-ice decline. Although the mean rates of erosion were decreasing at a decadal scale, cluster analysis captured a slight increase in the retreat for 71% of the erosional stretch, which is apparently related to the forcing of wind–wave and thermal energy. Erosional hotspots (up to −7.9 m/yr) occurred mainly in the alignment of Cape Kharasavey and were predominantly caused by direct human impact. The presented study highlights the non-linear interaction of the Arctic coastal change and environmental drivers that require further upscaling of the applied models and remote sensing data.

Kazhukalo, G.; Belova, N.; Overduin, P.; Ogorodov, S.; Bogatova, D., and Shilova, O., 2024. Carbon emission from ice-rich permafrost bluffs: Insights from coastal erosion and sediment redistribution estimations, Kharasavey, Kara Sea. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 458-462. Charlotte (North Carolina), ISSN 0749-0208. In the present study, geospatial data of shoreline change, the volume of eroded sediments and facies-specific organic carbon density were combined to calculate local-scale carbon flux for the Kharasavey key site, Kara Sea. Geochemical analyses of the 97 samples from different facial units along a 9-km coastal bluff gave a mean annual carbon flux (TOCs) value of 656.3 ty-1 or 73 ty-1km-1. Both organic carbon concentrations in Late Pleistocene-Holocene sediments and values of sediments flux are consistent with previous estimates for the Kara Sea and can be extrapolated to similarly composed reaches. Grain-size analysis revealed no substantial longshore transport and potential re-sequestration of carbon northwards of the bluff. These results highlight the importance of carbon loss assessment from ice-rich permafrost bluffs across the entire Arctic coast for further climate change projections.

The article presents the results of an extensive study of the bottom topography of the Ob River Gulf in the Kara Sea, which is a follow-up to the long-term studies of the authors. It refines the existing ideas and aims at solving a fundamental problem of reconstructing the conditions for the formation of bottom topography in the shallow bays of the Kara Sea in the Late Pleistocene and Holocene. The work aims to create a regional characteristic of the geomorphologic structure of the Ob River Gulf bottom. The initial data on the bottom topography were taken from marine navigational maps and sounding boards at a scale of 1:50 000 - 1:100 000. We processed and interpreted the collected cartographic material to create a detailed DEM of the bottom and a bathymetric map at a scale of 1:200 000 with an isobaths interval of 1 m. In addition to bathymetric data, the compilation of a geomorphologic map engaged a large amount of literature and stock materials on geomorphology, geology, and geocryology of the region. The original morphogenetic legend was elaborated with due account of current ideas regarding the conditions for the formation of periglacial plains relief at the regressive stage of the Kara Sea shelf evolution. It was found that the relict fluvial relief prevails within the gulf and was partly modified by subaqueous processes during post-LGM transgression and the current epoch. We have indicated the most critical features of the structure and pattern of the flooded pravalley of the Ob River, as well as the total ancient erosion network. The selected individual forms and relief elements take into account the scale of objects and the degree of their generalization on the map and give an idea of the development of relief-forming processes both at the subaerial stage and under subaqueous conditions, including specific features of modern dynamics of the coastal and bottom relief.

Ogorodov, S.; Shabanova, N.; Kazhukalo, G.; Bogatova, D.; Ermolov, A.; Novikova, A., and Shilova, O., 2024. Gulf of Ob coasts in the XXI century under changing environments. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 346-350. Charlotte (North Carolina), ISSN 0749-0208. The Kara Sea coastal zone is the main area of economic development in the West Russian Arctic in the XXI century. Although much of the infrastructure hubs are settled along the coasts of the Ob Gulf, most of the coastal erosion studies were dedicated to an analysis of western Kara Sea key sites. Dampened wave climate in this unique estuary is regarded as the cause of relatively low coastal erodibility. The present broad-scale analysis of climatic features showed a substantial increase of air thawing, wind-wave energy and ice-free period. The peak values of the wind-wave energy potential are observed along Eastern Yamal coasts. Historical trend of marsh (laida) progradation appears to have ceased due to the drastic acceleration of hydrometeorological forcing. These results emphasize that sheltered stretches of an enclosed bays and open-ocean shorelines may face equally vast erosion rates.