Early history of the Western Pacific Warm Pool during the middle to late Miocene (similar to 13.2-5.8 Ma): Role of sea-level change and implications for equatorial circulation

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 海洋科技动态信息-印太暖池系统研究

	Early history of the Western Pacific Warm Pool during the middle to late Miocene (similar to 13.2-5.8 Ma): Role of sea-level change and implications for equatorial circulation
	Nathan, SA ; Leckie, RM
刊名	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
	2009
卷号	274 期号:40606 页码:140-159
关键词	Western Pacific Warm Pool Carbonate crash Biogenic bloom Equatorial Pacific Indonesian Seaway Planktic foraminiferal isotope paleoecology Middle to late Miocene Mi events Sea level Ocean circulation Central American Seaway
ISSN号	0031-0182
通讯作者	mleckie@geo.umass.edu
中文摘要	We document the waxing and waning of a "proto-warm pool" in the western equatorial Pacific (WEP) based on a study of multi-species planktic foraminiferal isotope ratios and census data spanning the 13.2-5.8 Ma interval at ODP Site 806. We hypothesize that the presence or absence of a proto-warm pool in the WEP, caused by the progressive tectonic constriction of the Indonesian Seaway and modulated by sea level fluctuations, created El Nino/La Nina-like alternations of hydrographic conditions across the equatorial Pacific during the late Miocene. This hypothesis is supported by the general antithetical relationship observed between carbonate productivity and preservation in the western and eastern equatorial Pacific, which we propose is caused by these alternating ocean-climate states. Warming of thermocline and surface waters, as well as a major change in planktic foraminferal assemblages record a two-step phase of proto-warm pool development similar to 11.6-10 Ma, which coincides with Miocene isotope events Mi5 and Mi6, and sea-level low stands. We suggest that these changes in the biota and structure of the upper water column in the WEP mark the initiation of a more modern equatorial current system, including the development of the Equatorial Undercurrent (EUC), as La Nina-like conditions became established across the tropical Pacific. This situation sustained carbonate and silica productivity in the eastern equatorial Pacific (EEP) at a time when carbonate preservation sharply declined in the Caribbean. Proto-warm pool weakening after similar to 10 Ma may have contributed to the nadir of a similar "carbonate crash" in the EEP. Cooling of the thermocline and increased abundances of thermocline taxa herald the decay of the proto-warm pool and higher productivity in the WEP, particularly similar to 9.0-8.8 Ma coincident with a major perturbation in tropical nannofossil assemblages. We suggest that this interval of increased productivity records El Nino-like conditions across the tropical Pacific and the initial phase of the widespread "biogenic bloom". Resurgence of a later proto-warm pool in the WEP similar to 6.5-6.1 Ma may have spurred renewed La Nina-like conditions, which contributed to a strong late phase of the "biogenic bloom" in the EEP. (C) 2009 Elsevier B.V. All rights reserved.
学科主题	Geography, Physical; Geosciences, Multidisciplinary; Paleontology
收录类别	SCI
原文出处	ELSEVIER SCIENCE BV
公开日期	2011-07-14
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/8417]
专题	南海海洋研究所_海洋科技动态信息-印太暖池系统研究
推荐引用方式 GB/T 7714	Nathan, SA,Leckie, RM. Early history of the Western Pacific Warm Pool during the middle to late Miocene (similar to 13.2-5.8 Ma): Role of sea-level change and implications for equatorial circulation[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2009,274(40606):140-159.
APA	Nathan, SA,&Leckie, RM.(2009).Early history of the Western Pacific Warm Pool during the middle to late Miocene (similar to 13.2-5.8 Ma): Role of sea-level change and implications for equatorial circulation.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,274(40606),140-159.
MLA	Nathan, SA,et al."Early history of the Western Pacific Warm Pool during the middle to late Miocene (similar to 13.2-5.8 Ma): Role of sea-level change and implications for equatorial circulation".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 274.40606(2009):140-159.