Seasonal Arctic Coastal Bluff Dynamics in Adventfjorden, Svalbard

Abstract

The geomorphic development of mixed-type coasts, which consist of bedrock cliffs overlain by unconsolidated sediment, is poorly known in the Arctic but important for addressing long-term coastal responses and potential socio-economic implications of climate change. At Vestpynten, Svalbard, ground temperatures, erosion rates and thermo-denudation processes along a 100 m coastal transect were recorded between May 2012 and August 2014 using thermistor strings, time-lapse photography and visual observation. The results indicate that mixed-type coasts oscillate between periods of active bluff recession (lasting from weeks to months) and stability (lasting from months to years). Thermo-denudation and nivation processes are the main erosional agents during periods of active recession. The highest rates of coastal bluff crest recession (50 and 20 cm in 2012 and 2013, respectively) were observed mainly in June. Erosion was closely related to the melting of a snow bank that accumulates on the lee side of the coastal bluff in winter. Waves acted only to remove material accumulated in scree slopes at the base of the coastal bluff, and were most effective in summer and autumn. Factors controlling the erosion of mixed-type coasts in Svalbard include the relative position/elevation of bedrock and the occurrence of snow banks in winter.

High Arctic coasts at risk—the case study of coastal zone development and degradation associated with climate changes and multidirectional human impacts in Longyearbyen (Adventfjorden, Svalbard)

“…Along the gravel‐dominated barrier system located in front of Longyearbyen Airport (Site a—Figure ), the total erosion of low‐lying, vegetated coastal bluffs was approximately 4 m (in period 1990–2009). We agree with Guégan and Christiansen () that observed erosion rates threaten the stability of road linking Longyearbyen and Bjørndalen. Across the whole barrier (from Vestpynten to Port 3), beach surface was polluted with fragments of coal, construction wood, glass, asphalt, and plastic trash posing a threat for the coastal ecosystem, especially for birds occupying the ponds along the shore zone.…”

“…The richness of marine environment and complexity of ecological processes operating in Adventfjorden have been thoroughly described in a state‐of‐the‐art review by Węsławski et al (). More recently, Guégan and Christiansen () presented the detailed study of seasonal changes along bedrock cliffs overlain by unconsolidated sediments at the entrance to Adventfjorden. In recent years, the functioning of central Spitsbergen coastal zone has been modified by increased duration of open‐water conditions and destabilization of coastal slopes (e.g., Larsson, ; Lønne & Nemec, ; Muckenhuber, Nilsen, Korosov, & Sandven, ).…”

Paraglacial coasts responses to glacier retreat and associated shifts in river floodplains over decadal timescales (1966–2016), Kongsfjorden, Svalbard

“…Nansen () was the first to describe coastal erosional processes in Svalbard and pointed out the role of frost action on coastal development. Few researchers showed that rocky coasts can be discussed in the context of paraglaciation, and studies have been conducted on Svalbard rocky coasts (Wangensteen, Eiken, Ødegård, & Sollid, ; Strzelecki, ; Strzelecki, ; Guégan & Christiansen, ; Swirad, Migon, & Strzelecki, ), as well as on unlithified coasts (Bourriquen et al, ; Héquette & Ruz, ; Mercier, ; Mercier & Laffly, ; Sessford, Baeverford, & Hormes, ; Strzelecki et al, ; Strzelecki et al, ; Strzelecki, Long, & Lloyd, ; Ziaja, Maciejowski, & Ostafin, ; Zagorski, ; Zagorski, Gajek, & Demczuk, ; Zagorski et al, ) and on Svalbard despite it providing an excellent field of investigation on coastal geomorphology in the High Arctic area in the context of global change.…”

Thermomechanical erosion modelling of Baydaratskaya Bay, Russia with COSMOS

“…A frozen bluff gradually thaws under the influence of warmer air temperatures, solar radiation, and snowmelt (Guégan & Christiansen, 2016), losing its strength in the process. It gradually becomes unstable and eventually fails, depositing scree at the base of the slope.…”

“…Snow cover protects the shore in early spring and summer, delaying the onset of thermodenudation, but can thaw and erode frozen sediment through nivation (Guégan & Christiansen, 2016).…”