Cliff retreat of permafrost coast in south‐west Baydaratskaya Bay, Kara Sea, during 2005–2016

Abstract

Recent years of increasing air temperature in the Arctic have led to a significant increase in the rate of retreat of permafrost coast, which has threatened livelihoods and infrastructure in these areas. The Kara Sea hosts more than 25% of the total Arctic coastline. However, little is known about how coastal erosion in the Kara Sea may have changed through time, and the climatic and environmental drivers remain unclear. Here we study coastal dynamics along a 4-km stretch of permafrost and sea-ice-affected coastline in south-west Baydaratskaya Bay of the Kara Sea, western Siberia, between 2005 and 2016, by using handheld differential GPS mapping and satellite imagery.We identified temporal and spatial variations in the retreat rates, ranging between 1.0 (+0.1/−0.6) and 1.9 (+0.7/−1.3) m/yr over the studied coastline during 2005-2016. We also made ground temperature measurements, subsurface resistivity measurements and estimates of wave energy flux of wind-driven ocean waves, to investigate the dominant climatic factors influencing the observed retreat rates through time. We found that wind-driven wave activity during sea-ice-free days influences the magnitude of coastal retreat in the study area, while recent temperature rise has contributed less to enhancing coastal retreat during the study period. This suggests that the amount of eroded sediment and the associated release of nutrient to the nearshore zone are controlled by the magnitude of wave activity, which may influence infrastructure along the permafrost coast and marine ecosystems in the proximal ocean.

A Probabilistic Model of Coastal Bluff-Top Erosion in High Latitudes Due to Thermoabrasion: A Case Study from Baydaratskaya Bay in the Kara Sea

“…The crest retreat to the left of the mouth of the Sabryavpenzya River was measured to be 9.1 m during the period of 2016-2017 [12]. This part of the coast has higher frozen bluffs (14 m) than the bluffs in Case #1, and the slope of the bluff face is almost vertical.…”

“…The coastline of the Kara Sea is the longest among all the water bodies within the Arctic Ocean [10] and composes more than one-quarter of the total length of Arctic coastline [11]. Isaev et al [12] reported erosion rates as high as 29.1 m/year along the coast of the Kara Sea. The mean annual erosion rate along this coast is estimated to be in the range from 0.2 m to 2.0 m per year [13].…”

“…However, they did not consider failure along predetermined planes; rather, they postulated that the combination of various environmental parameters determines the failure planes inside the bluff. Isaev et al [12] estimated the rate of retreat of coastal bluffs based on the relation among the wave energy flux, ground temperature and resistivity of frozen ice-rich material on the premise that the resistivity of frozen materials is significantly higher than that of unfrozen materials. They further observed that wind-driven wave activity during the open water season influences the magnitude of retreat, whereas recent temperature increases contributed relatively little to coastal retreat during the period of 2005 to 2016 along the coastline of the Kara Sea.…”

Winter air temperature during the Holocene optimum in the north‐eastern part of the east European plain based on ice wedge stable isotope records

“…A high ice content of the sediments and sea wave activity favored coastal retreat in the study area. During 2005–2014, wind‐driven ocean wave activity during the sea‐ice‐free period was shown to influence the magnitude of retreat more than recent temperature increase …”

Tsunamis unleashed by rapidly warming Arctic degrade coastal landscapes and communities – case study of Nuugaatsiaq, western Greenland

“…Most of the recent Arctic coastal change studies concentrated on accelerated coastal erosion rates in locations spread 170 across the Arctic region and associated them with diminishing sea-ice extent, longer exposure to storm wave impacts, and thawing coastal permafrost (e.g Farquharson et al, 2018;Irrgang et al, 2018;. Gibbs et al, 2019;Isaev et al, 2019). Also, in glaciated parts of the Arctic, such as Greenland or Svalbard, coastal research focused on the response of coastal zone to increased delivery of glacial sediments (e.g Bendixen et al, 2017;Strzelecki et al, 2018)…”