The Marine Isotope Stage 19 in the mid-latitude North Atlantic Ocean; astronomical signature and intra-interglacial variability

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doi: 10.1016/j.quascirev.2014.10.024
Author(s): Ferretti, Patrizia; Crowhurst, Simon J.; Naafs, B. David A.; Barbante, Carlo
Author Affiliation(s): Primary:
Consiglio Nazionale delle Ricerche, Istituto per la Dinamica dei Processi Ambientali, Venice, Italy
University of Cambridge, United Kingdom
University of Bristol, United Kingdom
Volume Title: Quaternary Science Reviews
Source: Quaternary Science Reviews, Vol.108, p.95-110. Publisher: Elsevier, International. ISSN: 0277-3791
Note: In English. 55 refs.; illus., incl. 1 table, sketch map
Summary: Since the seminal work by Hays et al. (1976), a plethora of studies has demonstrated a correlation between orbital variations and climatic change. However, information on how changes in orbital boundary conditions affected the frequency and amplitude of millennial-scale climate variability is still fragmentary. The Marine Isotope Stage (MIS) 19, an interglacial centred at around 785 ka, provides an opportunity to pursue this question and test the hypothesis that the long-term processes set up the boundary conditions within which the short-term processes operate. Similarly to the current interglacial, MIS 19 is characterised by a minimum of the 400-kyr eccentricity cycle, subdued amplitude of precessional changes, and small amplitude variations in insolation. Here we examine the record of climatic conditions during MIS 19 using high-resolution stable isotope records from benthic and planktonic foraminifera from a sedimentary sequence in the North Atlantic (Integrated Ocean Drilling Program Expedition 306, Site U1313) in order to assess the stability and duration of this interglacial, and evaluate the climate system's response in the millennial band to known orbitally induced insolation changes. Benthic and planktonic foraminiferal δ18O values indicate relatively stable conditions during the peak warmth of MIS 19, but sea-surface and deep-water reconstructions start diverging during the transition towards the glacial MIS 18, when large, cold excursions disrupt the surface waters whereas low amplitude millennial scale fluctuations persist in the deep waters as recorded by the oxygen isotope signal. The glacial inception occurred at ∼779 ka, in agreement with an increased abundance of tetra-unsaturated alkenones, reflecting the influence of icebergs and associated meltwater pulses and high-latitude waters at the study site. After having combined the new results with previous data from the same site, and using a variety of time series analysis techniques, we evaluate the evolution of millennial climate variability in response to changing orbital boundary conditions during the Early-Middle Pleistocene. Suborbital variability in both surface- and deep-water records is mainly concentrated at a period of ∼11 kyr and, additionally, at ∼5.8 and ∼3.9 kyr in the deep ocean; these periods are equal to harmonics of precession band oscillations. The fact that the response at the 11 kyr period increased over the same interval during which the amplitude of the response to the precessional cycle increased supports the notion that most of the variance in the 11 kyr band in the sedimentary record is nonlinearly transferred from precession band oscillations. Considering that these periodicities are important features in the equatorial and intertropical insolation, these observations are in line with the view that the low-latitude regions play an important role in the response of the climate system to the astronomical forcing. We conclude that the effect of the orbitally induced insolation is of fundamental importance in regulating the timing and amplitude of millennial scale climate variability. Abstract Copyright (2015) Elsevier, B.V.
Year of Publication: 2015
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Bermuda Rise; Cenozoic; Chemostratigraphy; Climate change; Climate forcing; Cores; Cycles; Expedition 303; Expedition 306; Expeditions 303/306; Foraminifera; IODP Site U1308; IODP Site U1313; Insolation; Integrated Ocean Drilling Program; Invertebrata; Isotope ratios; Isotopes; Leg 162; Leg 172; MIS 19; Marine sediments; Microfossils; Mid-Atlantic Ridge; Middle Pleistocene; North Atlantic; Northeast Atlantic; O-18/O-16; ODP Site 1063; ODP Site 983; Ocean Drilling Program; Orbital forcing; Oxygen; Paleo-oceanography; Paleoclimatology; Paleotemperature; Pleistocene; Precession; Protista; Quaternary; Reconstruction; Reykjanes Ridge; Sediments; Stable isotopes
Coordinates: N602412 N602412 W0233826 W0233826
N495300 N495300 W0241400 W0241400
Record ID: 2016022644
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands