Atlantic overturning responses to obliquity and precession over the last 3 Myr. (6th February 2014)

• Record Type: Journal Article
• Authors: Lisiecki, L. E.
• Is Part Of: Paleoceanography. Volume 29:Number 2(2014:Jun.)
• Page Start: 71
• Page End: 86
• Publication Date: 2014-02-06
• Subjects: Paleoceanography -- Periodicals; 551.46
• DOI: 10.1002/2013PA002505
• Languages: English
• ISSNs: 0883-8305

Abstract

<abstract abstract-type="main" id="palo20076-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="palo20076-para-0001">This study analyzes 39 Atlantic and seven Pacific benthic <italic>δ</italic>¹³C records to characterize obliquity and precession responses in Atlantic overturning since 3 Ma. Regional benthic <italic>δ</italic>¹³C stacks are also analyzed. A major transition in orbital responses is observed at 1.5–1.6 Ma coincident with the first glacial shoaling of Northern Component Water. Since ∼1.5 Ma, the phases of Atlantic benthic <italic>δ</italic>¹³C records from 2300 to 4000 m depth lag maximum obliquity by 59° (6.7 kyr) and June perihelion precession forcing by 133° (8.5 kyr). Comparison with North Atlantic sea surface temperature suggests that these orbital responses (particularly precession) in middle deep Atlantic <italic>δ</italic>¹³C are associated with changes in ocean heat transport and overturning rates. The mid‐Pleistocene transition had little effect on the obliquity and precession phases of benthic <italic>δ</italic>¹³C but did result in a ∼50% decrease in the obliquity power of middle deep Atlantic <italic>δ</italic>¹³C at 0.6 Ma.</p> </abstract>