DOI: 10.5194/cp-11-803-2015
Scopus记录号: 2-s2.0-84930938583
论文题名: Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera
作者: Kubota Y. ; Kimoto K. ; Itaki T. ; Yokoyama Y. ; Miyairi Y. ; Matsuzaki H.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2015
卷: 11, 期: 6 起始页码: 803
结束页码: 824
语种: 英语
Scopus关键词: benthic foraminifera
; bottom water
; calcium
; carbon isotope
; Heinrich event
; Holocene
; Last Glacial Maximum
; magnesium
; marine sediment
; oxygen isotope
; paleotemperature
; sediment core
; stable isotope
; upwelling
; water depth
; water temperature
; Japan
; Okinawa Island
; Okinawa Islands
; Okinawa [Ryukyu Islands]
; Pacific Ocean
; Pacific Ocean (North)
; Pacific Ocean (Northwest)
; Ryukyu Islands
; Alle
; Cibicidoides wuellerstorfi
; Foraminifera
英文摘要: To understand bottom water variability in the subtropical northwestern Pacific, bottom water temperatures (BWTs), carbon isotopes (δ13C), and oxygen isotopes of seawater (δ18Ow ) at a water depth of 1166m were reconstructed from 26 kyr BP to present. A new regional Mg= Ca calibration for the benthic foraminifera Cibicidoides wuellerstorfi (type B) was established to convert the benthic Mg= Ca value to BWT, based on 26 surface sediment samples and two core-top samples retrieved around Okinawa Island. During the Last Glacial Maximum (LGM), the δ18Ow in the intermediate water in the northwestern South Pacific was ∼0.4% lower than in the deep South Pacific, indicating a greater vertical salinity gradient than at present. This salinity (and probably density) structure would have led to stratification in the intermediate and deep Pacific, which would, in turn, have greatly influenced carbon storage during the glacial time. The benthic Mg= Ca and δ18Ow records suggest changes that seem to follow Heinrich event 1 (H1) and the Bølling-Alleød (B/A) and Younger Dryas (YD) intervals, with BWT higher during H1 (δ17 kyr BP) and YD (δ12 kyr BP) and lower during B/A (δ14 kyr BP). The warming in the bottom water during H1 suggests increased contribution of North Pacific Intermediate Water (NPIW) to the subtropical northwestern Pacific and decreased upwelling of cooler waters from the abyssal North Pacific. During the interval from 17 to 14.5 kyr BP, the BWT tended to decrease successively in association with a decrease in δ13C values, presumably as a result of increased upwelling of the abyssal waters to the intermediate depths of the North Pacific caused by shoaling and enhancement of the southward return flow of Pacific Deep Water (PDW). During the Holocene, the millennial- to sub-millennial-scale variations in the BWT generally correlate with the sea surface temperatures in the Okhotsk Sea, the source region of the NPIW, suggesting that changes in the BWT are linked to changes in the NPIW production rate. © 2015 Author(s). 资助项目: JAMSTEC, Japan Society for the Promotion of Science
; JSPS, Japan Society for the Promotion of Science
; JSPS, Japan Society for the Promotion of Science
; JSPS, Japan Society for the Promotion of Science
; JSPS, Japan Society for the Promotion of Science
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49140
Appears in Collections: 气候变化与战略
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Recommended Citation:
Kubota Y.,Kimoto K.,Itaki T.,et al. Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera[J]. Climate of the Past,2015-01-01,11(6)