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DOI	10.5194/tc-8-1121-2014
	How old is the ice beneath Dome A, Antarctica?
	Sun B.; Moore J.C.; Zwinger T.; Zhao L.; Steinhage D.; Tang X.; Zhang D.; Cui X.; Martín C.
发表日期	2014
ISSN	19940416
卷号	8 期号:3
英文摘要	Chinese scientists will start to drill a deep ice core at Kunlun station near Dome A in the near future. Recent work has predicted that Dome A is a location where ice older than 1 million years can be found. We model flow, temperature and the age of the ice by applying a three-dimensional, thermomechanically coupled full-Stokes model to a 70 × 70 km2 domain around Kunlun station, using isotropic non-linear rheology and different prescribed anisotropic ice fabrics that vary the evolution from isotropic to single maximum at 1/3 or 2/3 depths. The variation in fabric is about as important as the uncertainties in geothermal heat flux in determining the vertical advection which in consequence controls both the basal temperature and the age profile. We find strongly variable basal ages across the domain since the ice varies greatly in thickness, and any basal melting effectively removes very old ice in the deepest parts of the subglacial valleys. Comparison with dated radar isochrones in the upper one third of the ice sheet cannot sufficiently constrain the age of the deeper ice, with uncertainties as large as 500 000 years in the basal age. We also assess basal age and thermal state sensitivities to geothermal heat flux and surface conditions. Despite expectations of modest changes in surface height over a glacial cycle at Dome A, even small variations in the evolution of surface conditions cause large variation in basal conditions, which is consistent with basal accretion features seen in radar surveys. © Author(s) 2014. CC Attribution 3.0 License.
学科领域	age determination; anisotropic medium; dating method; ice core; ice thickness; melting; subglacial environment; China
语种	英语
scopus关键词	age determination; anisotropic medium; dating method; ice core; ice thickness; melting; subglacial environment; China
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/120096
作者单位	Polar Research Institute of China, Shanghai 200129, China; College of Global Change and Earth System Science, Beijing Normal University, Beijing, China; Arctic Centre, University of Lapland, P.O. Box 122, 96101 Rovaniemi, Finland; Department of Earth Sciences, Uppsala University, Villavägen 16, Uppsala, 75236, Sweden; CSC-IT Center for Science Ltd., Espoo, Finland; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
推荐引用方式 GB/T 7714	Sun B.,Moore J.C.,Zwinger T.,et al. How old is the ice beneath Dome A, Antarctica?[J],2014,8(3).
APA	Sun B..,Moore J.C..,Zwinger T..,Zhao L..,Steinhage D..,...&Martín C..(2014).How old is the ice beneath Dome A, Antarctica?.Cryosphere,8(3).
MLA	Sun B.,et al."How old is the ice beneath Dome A, Antarctica?".Cryosphere 8.3(2014).