Indian Ocean sedimentary calcium carbonate distribution and its implications for the glacial deep ocean circulation

Zhang, Handan; Luo, Yanru; Yu, Jimin; Zhang, Lanlan; Xiang, Rong; Yu, Zhaojie; Huang, Huang

doi:10.1016/j.quascirev.2022.107490

Cited by 8 publications

(1 citation statement)

References 49 publications

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“…Such a difference in the POC flux peak between Stations SBBT and EIOT seems due to the influence of the Wyrtki Jet during the inter‐monsoon season (Figure 1). In addition, the Bay of Bengal is exceptional in carbonate sedimentation with the water depth due to dilution by the abundant supply of lithogenic matter from the GBM River system, compared with other areas of the Indian Ocean (Zhang et al., 2022).…”

Section: Methodsmentioning

confidence: 99%

Ballasting of Particulate Organic Matter at the Ninetyeast Ridge During the Mid‐Brunhes Dissolution Interval and Long‐Term Implications for Zonal Change in Tropical Indian Oceanography

Takata,

Khim,

Hyeong

et al. 2024

Paleoceanog and Paleoclimatol

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We investigated benthic foraminifera in cores GPC03 and GPC04 in the northeast tropical Indian Ocean (TIO) over the past ∼450 ka to evaluate the ballasting effect of particulate organic matter (POM) and the long‐term zonal change during the mid‐Brunhes dissolution interval (MBDI). Today, interannual climate and oceanographic variability in the TIO is governed by the Indian Ocean Dipole (IOD), which manifests as asymmetric zonal oceanographic change. Previous studies have been conducted to uncover such zonal paleoceanographic change and have referred to their climatic pattern as an “IOD‐like mode.” In the northeast TIO, after ∼390 ka, contributions of lithogenic matter and %Nuttallides umbonifer were unusually high under the better carbonate preservation conditions during glacial periods. Our findings suggest that the effect of lithogenic matter from the Ganga‐Brahmaputra‐Meghna River system increased significantly under glacial low sea‐level conditions, possibly by lateral transport along the continental slope. As a result, ballasting of POM seemed more efficient during glacial periods by abundant riverine lithogenic particles. In addition, the long‐term (∼320–200 ka) trend of high benthic foraminiferal accumulation rate (BFAR) and several short‐term fluctuations of high BFAR at ∼310, ∼280, ∼260, and ∼240 ka were discernible. We attribute these changes to increased paleoproductivity driven by upwelling, which may be related to the Indian Ocean equatorial westerlies and Indian summer monsoon dynamics via variations arising from precession. We propose that a long‐term mean‐state transition of IOD‐like mode might have occurred during the MBDI, similar to other hypotheses invoking concomitant changes in the El Niño‐Southern Oscillation system.

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Section: Methodsmentioning

confidence: 99%