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TitreHistory of sea ice in the Arctic
AuteurPolyak, L; Alley, R B; Andrews, J T; Brigham-Grette, J; Cronin, T M; Darby, D A; Dyke, A S; Fitzpatrick, J J; Funder, S; Holland, M; Jennings, A E; Miller, G H; O'Regan, M; Savelle, J; Serreze, M; St. John, K; White, J W C; Wolff, E
SourceQuaternary Science Reviews vol. 29, 2010 p. 1757-1778,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090026
ÉditeurElsevier BV
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceRégion extracotière du nord; Nunavut; Territoires du Nord-Ouest; Yukon
SNRC26; 27; 28; 29; 36; 37; 38; 39; 46; 47; 48; 49; 56; 57; 58; 59; 66; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88; 89; 96; 97; 98; 99; 120; 340; 560
Lat/Long OENS-180.0000 180.0000 90.0000 64.0000
Sujetsglace; épaisseur de la glace; écoulement glaciaire; concentration de glace; glace marine; Eocene; Paléocène; Holocène; paléoclimats; végétation; antecedents glaciaires; etudes de l'environnement; analyse environnementales; géologie des dépôts meubles/géomorphologie; géologie de l'environnement; Nature et environnement; Cénozoïque; Quaternaire
Illustrationscartes de localisation; graphiques; tableaux; graphiques; photographies aériennes
ProgrammeGéosciences de changements climatiques, Études paléo-environnementales sur les changements climatiques
Résumé(disponible en anglais seulement)
Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This information can be provided by proxy records fromthe Arctic Ocean floor and from the surrounding coasts. Although existing records are far from complete, they indicate that sea ice became a feature of the Arctic by 47 Ma, following a pronounced decline in atmospheric pCO2 after the Paleocene - Eocene Thermal Optimum, and consistently covered at least part of the Arctic Ocean for no less than the last 13 - 14 million years. Ice was apparently most widespread during the last 2 - 3 million years, in accordance with Earth's overall cooler climate. Nevertheless, episodes of considerably reduced sea ice or even seasonally ice-free conditions occurred during warmer periods linked to orbital variations. The last low-ice event related to orbital forcing (high insolation) was in the early Holocene, after which the northern high latitudes cooled overall, with some superimposed shorterterm (multidecadal to millennial-scale) and lower-magnitude variability. The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities.