Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8914706 | Quaternary Science Reviews | 2018 | 12 Pages |
Abstract
Paleoceanographic changes in response to Holocene climate variability in Bigo Bay, west Antarctic Peninsula (WAP) were reconstructed through geochemical, isotopic, sedimentological, and microfossil analysis. Core WAP13-GC47 is composed of 4 lithologic units. Unit 4 was deposited under ice shelf settings. Unit 3 represents the mid-Holocene open marine conditions. Unit 2 indicates lateral sediment transport by a glacier advance during the Neoglacial period. The chronological contrast between the timing of open marine conditions at core WAP13-GC47 (ca. 7060â¯cal.â¯yr BP at 540â¯cm) and the ages of calcareous shell fragments (ca. 8500â¯cal.â¯yr BP) in Unit 2b suggests sediment reworking during the Neoglacial period. Unit 1 was deposited during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). Surface water productivity, represented by biogenic opal and total organic carbon (TOC) concentrations, increased and bulk δ15N (nitrate utilization) decreased during the warmer early to middle Holocene and the MWP. In contrast, surface water productivity decreased with increased bulk δ15N during the colder Neoglacial period and LIA in Bigo Bay. The nitrate utilization was enhanced during cold periods in association with strong surface water stratification resulting from increased sea ice meltwater discharge or proximity to an ice shelf calving front in Bigo Bay. Reduced nitrate utilization during warm periods is related to weak stratification induced by less sea ice meltwater input and stronger Circumpolar Deep Water influence.
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Physical Sciences and Engineering
Earth and Planetary Sciences
Geology
Authors
Sunghan Kim, Kyu-Cheul Yoo, Jae Il Lee, Boo-Keun Khim, Young-Suk Bak, Min Kyung Lee, Jongmin Lee, Eugene W. Domack, Andrew J. Christ, Ho Il Yoon,