Beryllium isotope variations recorded in the Adélie Basin, East Antarctica reflect Holocene changes in ice dynamics, productivity, and scavenging efficiency
| Type | Article | ||||||||
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| Date | 2022-07 | ||||||||
| Language | English | ||||||||
| Author(s) | Behrens Bethany C. 1, 2, Yokoyama Yusuke1, 2, 3, 4, 5, Miyairi Yosuke1, Sproson Adam D.1, 4, Yamane Masako6, Jimenez-Espejo Francisco J.4, 7, McKay Robert M.8, Johnson Katelyn M.8, 9, Escutia Carlota7, Dunbar Robert B.10 |
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| Affiliation(s) | 1 : Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan 2 : Graduate Program on Environmental Science, University of Tokyo, Komaba, Meguro, Tokyo, 153-0041, Japan 3 : Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Hongo, Bunkyō, Tokyo, 113-8654, Japan 4 : Biogeochemistry Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushimacho, Yokosuka, Kanagawa Prefecture, 237-0061, Japan 5 : Research School of Physics, The Australian National University, Acton ACT, 2601, Australia 6 : Institute for Space-Earth Environmental Research, Nagoya University, Furocho, Chikusa, Nagoya, Aichi, 464-8601, Japan 7 : Andalusian Earth Sciences Institute (IACT), CSIC-University of Granada, Armilla, Spain 8 : Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand 9 : GNS Science, National Ice Core Research Laboratory, Lower Hutt, New Zealand 10 : School of Earth, Energy, and Environmental Sciences, Stanford University, Stanford, CA, USA |
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| Source | Quaternary Science Advances (2666-0334) (Elsevier BV), 2022-07 , Vol. 7 , P. 100054 (10p.) | ||||||||
| DOI | 10.1016/j.qsa.2022.100054 | ||||||||
| Keyword(s) | Holocene, East Antarctica, Cosmogenic nuclides, Beryllium isotopes, Scavenging | ||||||||
| Abstract | The Adélie Basin is a relatively small (∼1600 km2), semi-enclosed continental shelf bathymetric depression located adjacent to the Wilkes Subglacial Basin, a basin underlying a sector of the East Antarctic Ice Sheet that contains ∼3–4 meters sea level equivalent of ice. Located within the Adélie Basin is a ∼184 m thick laminated sediment deposit, the Adélie Drift, ideal for examining regional changes in ice sheet and ocean dynamics. Here, we examine the ratio of reactive beryllium-10 to reactive beryllium-9 ((10Be/9Be)reac) in a marine sediment core obtained from the Adélie Drift to assess these changes during the Holocene epoch (11.7 ka BP to present). The (10Be/9Be)reac record provides insight into changes in freshwater input, primary productivity, and scavenging efficiency, while removing the influence of particle size on 10Be concentration. During the early Holocene, (10Be/9Be)reac ratios indicate increased meltwater discharge from ca. 11.7 to 10 ka BP, as grounded ice retreated from the Adélie Basin and adjacent bathymetric highs. After ∼10 ka BP, beryllium isotopes are influenced by scavenging efficiency and dilution controlled by ocean currents and accumulation rate, operating alongside meltwater input, suggesting there are additional factors to consider when using (10Be/9Be)reac as a proxy for ice shelf cover and glacial dynamics. |
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