ice
; air temperature
; Arctic
; Article
; Canada
; Greenland
; Holocene
; ice cap
; ice sheet
; priority journal
; warming
英文摘要:
We present a revised and extended high Arctic air temperature reconstruction from a single proxy that spans the past ∼12,000 y (up to 2009 CE). Our reconstruction from the Agassiz ice cap (Ellesmere Island, Canada) indicates an earlier and warmer Holocene thermal maximum with early Holocene temperatures that are 4-5 °C warmer compared with a previous reconstruction, and regularly exceed contemporary values for a period of ∼3,000 y. Our results show that air temperatures in this region are now at their warmest in the past 6,800-7,800 y, and that the recent rate of temperature change is unprecedented over the entire Holocene. The warmer early Holocene inferred from the Agassiz ice core leads to an estimated ∼1 km of ice thinning in northwest Greenland during the early Holocene using the Camp Century ice core. Ice modeling results show that this large thinning is consistent with our air temperature reconstruction. The modeling results also demonstrate the broader significance of the enhanced warming, with a retreat of the northern ice margin behind its present position in the mid Holocene and a ∼25% increase in total Greenland ice sheet mass loss (∼1.4 m sea-level equivalent) during the last deglaciation, both of which have implications for interpreting geodetic measurements of land uplift and gravity changes in northern Greenland.
Lecavalier, B.S., Department of Physics and Physical Oceanography, Memorial University, St. John's, A1B 3X7, Canada; Fisher, D.A., Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, K1N 6N5, Canada; Milne, G.A., Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, K1N 6N5, Canada; Vinther, B.M., Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark; Tarasov, L., Department of Physics and Physical Oceanography, Memorial University, St. John's, A1B 3X7, Canada; Huybrechts, P., Earth System Science and Departement Geografie, Vrije Universiteit Brussel, Brussels, 1050, Belgium; Lacelle, D., Department of Geography, University of Ottawa, Ottawa, K1N 6N5, Canada; Main, B., Department of Geography, University of Ottawa, Ottawa, K1N 6N5, Canada; Zheng, J., Geological Survey of Canada, Natural Resources Canada, Ottawa, K1A 0E8, Canada; Bourgeois, J., Consorminex Inc., Gatineau, J8R 3Y3, Canada; Dyke, A.S., Department of Earth Sciences, Dalhousie University, Halifax, B3H 4R2, Canada, Department of Anthropology, McGill University, Montreal, H3A 2T7, Canada
Recommended Citation:
Lecavalier B.S.,Fisher D.A.,Milne G.A.,et al. High Arctic Holocene temperature record from the Agassiz ice cap and Greenland ice sheet evolution[J]. Proceedings of the National Academy of Sciences of the United States of America,2017-01-01,114(23)