Sea surface temperature reconstruction for the middle Miocene Southern Ocean

Magnesium/calcium data from Southern Ocean planktonic foraminifera demonstrate that high-latitude (~55°S) southwest Pacific sea surface temperatures (SSTs) cooled 6° to 7°C during the middle Miocene climate transition (14.2 to 13.8 million years ago). Stepwise surface cooling is paced by eccentricit...

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Bibliographic Details
Main Authors: Shevenell, Amelia E, Kennett, James P, Lea, David W
Format: Other/Unknown Material
Language:English
Published: PANGAEA 2004
Subjects:
189-1170A
189-1171C
DRILL
Drilling/drill rig
Indian Ocean
Joides Resolution
Leg189
Ocean Drilling Program
ODP
South Pacific Ocean
Antarc*
Antarctic
Planktonic foraminifera
Southern Ocean
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.772059
https://doi.org/10.1594/PANGAEA.772059
Description
Summary:Magnesium/calcium data from Southern Ocean planktonic foraminifera demonstrate that high-latitude (~55°S) southwest Pacific sea surface temperatures (SSTs) cooled 6° to 7°C during the middle Miocene climate transition (14.2 to 13.8 million years ago). Stepwise surface cooling is paced by eccentricity forcing and precedes Antarctic cryosphere expansion by ~60 thousand years, suggesting the involvement of additional feedbacks during this interval of inferred low-atmospheric partial pressure of CO2 (pCO2). Comparing SSTs and global carbon cycling proxies challenges the notion that episodic pCO2 drawdown drove this major Cenozoic climate transition. SST, salinity, and ice-volume trends suggest instead that orbitally paced ocean circulation changes altered meridional heat/vapor transport, triggering ice growth and global cooling.

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