GEOSCAN, résultats de la recherche


TitreClimate change: numerical modelling of sedimentation and coastal processes, eastern Canadian Arctic
AuteurSyvitski, J P M; Andrews, J T
SourceArctic and Alpine Research vol. 26, no. 3, 1994 p. 199-212,
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 40293
Séries alt.PALE (Paleoclimates from Arctic Lakes and Estuaries), Contribution 14
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceNunavut; Région extracotière du nord
Lat/Long OENS -92.0000 -55.0000 74.0000 50.0000
Sujetstransport des sediments; mécanismes de transport; établissement de modèles; dépôts fluviaux; climat arctique; effets climatiques; niveaux d'eau; variations du niveau de la mer; nappes glaciaires; courants de turbidite; sandur; changement climatique; géomathématique; géologie des dépôts meubles/géomorphologie; Nature et environnement
Illustrationslocation maps; aerial photographs; diagrams; schematic cross-sections; tables; graphs; plots
Résumé(disponible en anglais seulement)
We use three sequential "water-sediment transport" numerical models to evaluate changes in fluvial sediment outputs for two near-future contrasting climate-change scenarios (warmer summers or warmer and moister winters) for the eastern Ca- nadian Arctic. Our integrated model generates values for deposition into a fiord basin. The effects of climate warming are imposed on 200-yr fluctuations in relative sea level (base level) that in turn have a long-term forcing associated with late Quaternary glacial unloading. Thus some areas are submerging (around the periphery of the former ice sheet) and others are emerging (inland at the heads of fiords). Small, short-term changes in sea level may involve meltwater supply to the world ocean from the melting of glaciers and ice sheets, and sea water expansion with a warming ocean. Alternatively, large ice sheets may also thicken over the short term (200 yr), thereby withdrawing water from the global hydrological cycle. Both climate scenarios result in an increased sediment flux over the next 200 yr. However, warmer summers will have the largest impact by (1) causing ice caps to melt, (2) inducing more expansive and turbid river plumes, (3) increasing progradation of the coastline into the sea, (4) raising relative sea level, and by (5) increasing the number and size of turbidity currents generated off river mouths. Warmer and moister winters that may lead to deviations from these impacts include (1) growth of ice caps, (2) fall of relative sea level, (3) stability of coastlines as increased sediment delivery keeps pace with changes in regional relative sea level, and (4) fewer basin turbidity currents, as more of the bedload is trapped on top of sandur surfaces.