Behrens, Bethany C.Yokoyama, YusukeMiyairi, YosukeSproson, Adam D.Yamane, MasakoJimenez-Espejo, Francisco J.McKay, RobertJohnson, Katelyn M.Escutia, CarlotaDunbar, Robert B2026-03-112026-03-112666-0334https://hdl.handle.net/1885/733807246The Adelie 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 m 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.Financial support for this study was provided by the Japan Society for the Promotion of Science ( JSPS ) KAKENHI ( 20H00193 ) to YY, JSPS Fellowship DC1 (20J21145) to BCB, and JSPS Post-Doctoral Fellowship (PE17712 and P18791) to ADS. RM was funded by the New Zealand Ministry of Business, Innovation and Employment through the Antarctic Science Platform (ANTA1801). CE and FJJ-E acknowledges funding through Spanish Ministry of Science and Innovation (grant CTM2017-89711-C2-1-P), co-funded by the European Union through FEDER funds.application/pdfen-AU© 2022 The Authorshttps://creativecommons.org/licenses/by-nc-nd/4.0/202210.1016/j.qsa.2022.1000542023-10-01CC BY-NC-ND license