DOI: 10.1016/j.quascirev.2016.07.005
Scopus记录号: 2-s2.0-84979633678
论文题名: Gradual and abrupt changes during the Mid-Pleistocene Transition
作者: Ford H.L. ; Sosdian S.M. ; Rosenthal Y. ; Raymo M.E.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 148 起始页码: 222
结束页码: 233
语种: 英语
英文关键词: Benthic foraminifera
; Mg/Ca
; Mid-Pleistocene Transition
; Palaeoceanography
Scopus关键词: Backward wave tubes
; Ice
; Oceanography
; Benthic foraminifera
; Enhanced sensitivity
; Interglacial cyclicity
; Long-term trend
; Ocean circulation
; Orbital forcing
; Palaeoceanography
; Pleistocene
; Climate change
; benthic foraminifera
; bottom water
; calcium
; climate variation
; cooling
; Deep Sea Drilling Project
; glacial-interglacial cycle
; ice cover
; ice sheet
; magnesium
; Ocean Drilling Program
; oceanic circulation
; orbital forcing
; paleoceanography
; Pleistocene
; water temperature
; Atlantic Ocean
; Atlantic Ocean (North)
; Pacific Ocean
; Pacific Ocean (South)
; Cibicidoides wuellerstorfi
; Foraminifera
; Oridorsalis umbonatus
; Uvigerina
英文摘要: During the Mid-Pleistocene Transition (MPT), the dominant glacial-interglacial cyclicity as inferred from the marine δ18O records of benthic foraminifera (δ18Obenthic) changed from 41 kyr to 100 kyr years in the absence of a comparable change in orbital forcing. Currently, only two Mg/Ca-derived, high-resolution bottom water temperature (BWT) records exist that can be used with δ18Obenthic records to separate temperature and ice volume signals over the Pleistocene. However, these two BWT records suggest a different pattern of climate change occurred over the MPT—a record from North Atlantic DSDP Site 607 suggests BWT decreased with no long-term trend in ice volume over the MPT, while South Pacific ODP Site 1123 suggests that BWT has been relatively stable over the last 1.5 Myr but that there was an abrupt increase in ice volume at ∼900 kyr. In this paper we attempt to reconcile these two views of climate change across the MPT. Specifically, we investigated the suggestion that the secular BWT trend obtained from Mg/Ca measurements on Cibicidoides wuellerstorfi and Oridorsalis umbonatus species from N. Atlantic Site 607 is biased by the possible influence of Δ[CO3 2−] on Mg/Ca values in these species by generating a low-resolution BWT record using Uvigerina spp., a genus whose Mg/Ca values are not thought to be influenced by Δ[CO3 2−]. We find a long-term BWT cooling of ∼2–3°C occurred from 1500 to ∼500 kyr in the N. Atlantic, consistent with the previously generated C. wuellerstorfi and O. umbonatus BWT record. We also find that changes in ocean circulation likely influenced δ18Obenthic, BWT, and δ18Oseawater records across the MPT. N. Atlantic BWT cooling starting at ∼1.2 Ma, presumably driven by high-latitude cooling, may have been a necessary precursor to a threshold response in climate-ice sheet behavior at ∼900 ka. At that point, a modest increase in ice volume and thermohaline reorganization may have caused enhanced sensitivity to the 100 kyr orbital cycle. © 2016 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59495
Appears in Collections: 过去全球变化的重建
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作者单位: Biology and Paleo Environment, Lamont-Doherty Earth Observatory, Palisades, NY, United States; School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom; Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, United States; Department of Earth and Atmospheric Sciences, Rutgers University, New Brunswick, NJ, United States
Recommended Citation:
Ford H.L.,Sosdian S.M.,Rosenthal Y.,et al. Gradual and abrupt changes during the Mid-Pleistocene Transition[J]. Quaternary Science Reviews,2016-01-01,148