GEOSCAN, résultats de la recherche


TitreMultitemporal analysis of a gravel-dominated coastline in the central Canadian Arctic Archipelago
AuteurSt-Hilaire-Gravel, D; Forbes, D L; Bell, T
SourceJournal of Coastal Research vol. 28, no. 2, 2012 p. 421-441,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110126
Documentpublication en série
Mediapapier; en ligne; numérique
SNRC58F/11; 58F/12; 58F/13; 58F/14
Lat/Long OENS-95.5000 -94.5000 74.8333 74.6667
Sujetsétudes côtières; érosion côtière; milieu côtièr; dépôts cotiers; plages; graviers; climat arctique; fluctuations climatiques; variations du niveau de la mer; changements du niveau de la mer; littoraux; variations du littoral; sédimentologie; géologie marine
Illustrationslocation maps; photographs; tables; plots
ProgrammeGestionn aire de programme - sciences de changements climatiques, Géosciences de changements climatiques
Résumé(disponible en anglais seulement)
This study assesses the stability of Arctic gravel coasts across a range of timescales, based on field and remote-sensing studies of three coastal sites near Resolute Bay, Nunavut. It considers shore-zone sensitivity to ice, wind, and wave forcing at storm-event and annual timescales within a longer-term context, including coastal emergence resulting from postglacial isostatic uplift partially counteracted by accelerating sea-level rise. Another long-term factor associated with climate change is the potential for increased seasonal depth of thaw in the beachface and nearshore. The coast in this area is ice bound on average for 10 months of the year, but the annual duration of ice cover has decreased over the past 30 years (1979 - 2009) by 0.95 d/y. A longer open-water season has implications for the number and timing of storm-wave events, with increased probability of storms impacting the coast later in the season when the seasonal thaw layer is approaching maximum thickness. Overall, shoreline progradation surpassed erosion in the Resolute area between 1958 and 2006, reflecting a combination of sediment supply and emergence. The coastal impacts of storms were found to be short lived and not necessarily indicative of longer-term trends. Gravel shorelines can be resilient in the face of intermittent storm impacts, but thresholds of stability in this high-latitude setting are poorly understood. If current trends of rising sea level, increasing open-water duration, and more frequent effective wave events continue, there is a heightened potential for more rapid coastal change in the region.