Strength and variability of the Oligocene Southern Ocean surface temperature gradient

被引：12

作者：

Hoem, Frida S. ^{[1
]}

Sauermilch, Isabel ^{[1
]}

Aleksinski, Adam K. ^{[2
]}

Huber, Matthew ^{[2
]}

Peterse, Francien ^{[1
]}

Sangiorgi, Francesca ^{[1
]}

Bijl, Peter K. ^{[1
]}

机构：

[1] Univ Utrecht, Dept Earth Sci, Utrecht, Netherlands

[2] Purdue Univ, Dept Earth Atmospher & Planetary Sci, W Lafayette, IN USA

来源：

COMMUNICATIONS EARTH & ENVIRONMENT | 2022年 / 3卷 / 01期

基金：

欧洲研究理事会; 美国国家科学基金会;

关键词：

ICE-SHEET VARIABILITY; OFFSHORE WILKES LAND; ANTARCTIC CIRCUMPOLAR CURRENT; LATE EOCENE; CLIMATE SENSITIVITY; DRAKE PASSAGE; ROSS SEA; EVOLUTION; MARINE; PALEOCEANOGRAPHY;

D O I：

10.1038/s43247-022-00666-5

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Large Oligocene Antarctic ice sheets co-existed with warm proximal waters offshore Wilkes Land. Here we provide a broader Southern Ocean perspective to such warmth by reconstructing the strength and variability of the Oligocene Australian-Antarctic latitudinal sea surface temperature gradient. Our Oligocene TEX86-based sea surface temperature record from offshore southern Australia shows temperate (20-29 & DEG;C) conditions throughout, despite northward tectonic drift. A persistent sea surface temperature gradient (similar to 5-10 & DEG;C) exists between Australia and Antarctica, which increases during glacial intervals. The sea surface temperature gradient increases from similar to 26 Ma, due to Antarctic-proximal cooling. Meanwhile, benthic foraminiferal oxygen isotope decline indicates ice loss/deep-sea warming. These contrasting patterns are difficult to explain by greenhouse gas forcing alone. Timing of the sea surface temperature cooling coincides with deepening of Drake Passage and matches results of ocean model experiments that demonstrate that Drake Passage opening cools Antarctic proximal waters. We conclude that Drake Passage deepening cooled Antarctic coasts which enhanced thermal isolation of Antarctica.

引用

页数：8

共 70 条

[1]

Barrett PJ, 2007, SPEC PUBL INT ASS SE, V39, P259

[2] Maastrichtian-Rupelian paleoclimates in the southwest Pacific - a critical re-evaluation of biomarker paleothermometry and dinoflagellate cyst paleoecology at Ocean Drilling Program Site 1172 [J].