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Cancellation of the Precessional Cycle in δ 18 O Records During the Early Pleistocene
Author(s) -
Morée Anne L.,
Sun Tianyi,
Bretones Anaïs,
Straume Eivind O.,
Nisancioglu Kerim,
Gebbie Geoffrey
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl090035
Subject(s) - pleistocene , interglacial , glacial period , geology , early pleistocene , precession , oceanography , paleontology , deep sea , physics , astronomy
The dominant pacing of glacial‐interglacial cycles in deep‐ocean δ 18 O records changed substantially during the Mid‐Pleistocene Transition. The precessional cycle (∼23 ky) is absent during the Early Pleistocene, which we show can be explained by cancellation of the hemispherically antiphased precessional cycle in the Early Pleistocene interior ocean. Such cancellation develops due to mixing of North Atlantic and Southern Ocean δ 18 O signals at depth, and shows characteristic spatial patterns. We explore the cancellation potential for different North Atlantic and Southern Ocean deep‐water source δ 18 O values using a tracer transport ocean model. Cancellation of precession occurs for all signal strengths and is widespread for a signal strength typical for the Early Pleistocene. Early Pleistocene precessional power is therefore likely incompletely archived in deep‐sea δ 18 O records, concealing the true periodicity of the glacial cycles in the two hemispheres.