Average time scale for Dome Fuji ice core, East Antarctica

元データ 国立極地研究所

概要

Three different approaches to ice-core age dating are employed to develop a depth-age relationship at Dome F: (1) correlation of the ice-core isotope record to the geophysical metronome(Milankovich surface temperature cycle) inferred from the deep borehole temperature profile at Vostok,(2) importing a known chronology from another(Devils Hole) paleoclimatic signal, and(3) direct ice sheet flow modeling. Inverse Monte Carlo sampling is used to constrain the accumulation rate reconstruction and ice flow simulations in order to find the best-fit glaciological time scale matched with the two other chronologies. General uncertainty of the different age estimates varies from 2 to 6kyr on average and reaches 6-14kyr at maximum. Whatever the causes of this discrepancy might be, they are thought to be of different origins, and the age errors are assumed to be independent. Thus, the average time scale for the Dome F ice core down to a depth of 2500m(ice age of 335kyr) is deduced consistently with all three age-depth relationships within the standard deviation limits of ±3.3kyr, and its accuracy is estimated as 1.4kyr on average. The constrained ice-sheet flow model allows extrapolation of the ice age-depth curve further to the glacier bottom and predicts the ages at depths of 2800, 3000, and 3050m to be 615±70, 1560±531, and 2985±1568kyr, respectively.

著者

Watanabe Okitsugu National Institute of Polar Research, Research Organization of Information and Systems
本堂 武夫 北大
Hondoh Takeo Institute of Low Temperature Science, Hokkaido University
Shoji Hitoshi Kitami Institute of Technology
Watanabe O National Institute Of Polar Research Research Organization Of Information And Systems
Watanabe Okitsugu National Institute Of Polar Research
Tsyganova Elena Kazan State University
Salamatin Andrey Institute of Low Temperature Science, Hokkaido University
Lipenkov Vladimir Institute of Low Temperature Science, Hokkaido University
Watanabe Okitsusgu National Institute of Polar Research
Hondoh Takeo Institute Of Low Temperature Science Hokkaido University
Lipenkov Vladimir Institute Of Low Temperature Science Hokkaido University
Salamatin Andrey Institute Of Low Temperature Science Hokkaido University

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