GEOSCAN, résultats de la recherche


TitreHolocene thinning of the Greenland ice sheet
AuteurVinther, B M; Buchart, S L; Clausen, H B; Dahl-Jensen, D; Johnsen, S J; Fisher, D A; Koerner, R M; Raynaud, D; Lipenkov, V; Andersen, K K; Blunier, T; Rasmussen, S O; Steffensen, J P; Svensson, A M
SourceNature vol. 461, 2009 p. 385-388,
LiensSupplementary information / Information supplementaire
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090324
ÉditeurSpringer Nature
Documentpublication en série
Mediapapier; en ligne; numérique
Formatshtml; pdf
Régionîle d'Ellesmere
Lat/Long OENS-72.0000 -20.0000 84.0000 58.0000
Sujetsanalyse environnementales; etudes de l'environnement; effets sur l'environnement; climat arctique; effets climatiques; climat; Holocène; échantillons de glace; épaisseur de la glace; champs de glace; glace; concentration de glace; carottes; étude de carottes; Calotte glaciaire du Groenland; changement climatique; géologie des dépôts meubles/géomorphologie; Nature et environnement; Cénozoïque; Quaternaire
ProgrammeGéosciences de changements climatiques, Études paléo-environnementales sur les changements climatiques
Diffusé2009 09 17
Résumé(disponible en anglais seulement)
On entering an era of global warming, the stability of the Greenland ice sheet (GIS) is an important concern1, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins2. Studying the response of the GIS to past climatic change may help to advance our understanding of GIS dynamics. Existing evidence from stable isotopes (d18O) in water from GIS ice cores suggests that Holocene climate variability on the GIS differed spatially3 and that a consistent Holocene climate optimum-the unusually warm period from about 9,000 to 6,000 years ago found in many northern-latitude palaeoclimate records4-did not exist. Here we extract both the Greenland Holocene temperature history and the evolution of GIS surface elevation at four GIS locations. We achieve this by comparing d18O from GIS ice cores3,5 with d18O from ice cores from small marginal icecaps. Contrary to the earlier and inconsistent d18O evidence from ice cores3,6, our new temperature history reveals a pronounced Holocene climatic optimum in Greenland coinciding with maximum thinning near the GIS margins. Our d18O-based results are corroborated by the air content of ice cores, a proxy for surface elevation7. State-of-the-art ice sheet models are generally found to be underestimating the extent and changes in GIS elevation and area; our findings may help to improve the ability of models to reproduce the GIS response to Holocene climate.