气候变化领域集成服务门户(CCPortal): Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: Inferences from dinoflagellate cysts and biomarker paleothermometry

CCPortal

DOI	10.5194/cp-16-1667-2020
	Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: Inferences from dinoflagellate cysts and biomarker paleothermometry
	Cramwinckel M.J.; Woelders L.; Huurdeman E.P.; Peterse F.; Gallagher S.J.; Pross J.; Burgess C.E.; Reichart G.-J.; Sluijs A.; Bijl P.K.
发表日期	2020
ISSN	18149324
起始页码	1667
结束页码	1689
卷号	16 期号:5
英文摘要	Global climate cooled from the early Eocene hothouse ( ∼ 52–50 Ma) to the latest Eocene (∼ 34 Ma). At the same time, the tectonic evolution of the Southern Ocean was characterized by the opening and deepening of circum- Antarctic gateways, which affected both surface- and deepocean circulation. The Tasmanian Gateway played a key role in regulating ocean throughflow between Australia and Antarctica. Southern Ocean surface currents through and around the Tasmanian Gateway have left recognizable tracers in the spatiotemporal distribution of plankton fossils, including organic-walled dinoflagellate cysts. This spatiotemporal distribution depends on both the physicochemical properties of the water masses and the path of surface-ocean currents. The extent to which climate and tectonics have influenced the distribution and composition of surface currents and thus fossil assemblages has, however, remained unclear. In particular, the contribution of climate change to oceanographic changes, superimposed on long-term and gradual changes induced by tectonics, is still poorly understood. To disentangle the effects of tectonism and climate in the southwest Pacific Ocean, we target a climatic deviation from the long-term Eocene cooling trend: the Middle Eocene Climatic Optimum (MECO; ∼ 40 Ma). This 500 kyr phase of global warming was unrelated to regional tectonism, and thus provides a test case to investigate the ocean’s physicochemical response to climate change alone.We reconstruct changes in surface-water circulation and temperature in and around the Tasmanian Gateway during the MECO through new palynological and organic geochemical records from the central Tasmanian Gateway (Ocean Drilling Program Site 1170), the Otway Basin (southeastern Australia), and the Hampden Beach section (New Zealand). Our results confirm that dinocyst communities track specific surface-ocean currents, yet the variability within the communities can be driven by superimposed temperature change. Together with published results from the east of the Tasmanian Gateway, our new results suggest a shift in surface-ocean circulation during the peak of MECO warmth. Simultaneous with high sea-surface temperatures in the Tasmanian Gateway area, pollen assem-blages indicate warm temperate rainforests with paratropical elements along the southeastern margin of Australia. Finally, based on new age constraints, we suggest that a regional southeast Australian transgression might have been coincident with the MECO. © 2020 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	biomarker; climate change; dinoflagellate cyst; global warming; oceanic circulation; palynology; tectonic evolution; throughflow; transgression; Antarctica; Australia; Colorado; Gateway; New Zealand; Otway Basin; Pacific Ocean; Pacific Ocean (Southwest); United States; Dinophyceae
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146674
作者单位	Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, Netherlands; Paleoenvironmental Dynamics Group, Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany; School of Earth Sciences, University of Melbourne, Melbourne, Australia; School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom; Nioz Royal Netherlands Institute for Sea Research, And Utrecht University, Den Burg, Texel, Netherlands; School of Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom; Cooperative Institute for Research in Environmental Sciences, Western Water Assessment, University of Colorado Boulder, Boulder, CO, United States; Now At: Shell Uk Ltd, Aberdeen, United Kingdom
推荐引用方式 GB/T 7714	Cramwinckel M.J.,Woelders L.,Huurdeman E.P.,et al. Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: Inferences from dinoflagellate cysts and biomarker paleothermometry[J],2020,16(5).
APA	Cramwinckel M.J..,Woelders L..,Huurdeman E.P..,Peterse F..,Gallagher S.J..,...&Bijl P.K..(2020).Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: Inferences from dinoflagellate cysts and biomarker paleothermometry.Climate of the Past,16(5).
MLA	Cramwinckel M.J.,et al."Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: Inferences from dinoflagellate cysts and biomarker paleothermometry".Climate of the Past 16.5(2020).