Late Miocene Onset of Tasman Leakage and Southern Hemisphere Supergyre Ushers in Near-Modern Circulation
Journal
Geophysical Research Letters
Journal Volume
48
Journal Issue
18
Date Issued
2021
Author(s)
Christensen B.A
De Vleeschouwer D
Henderiks J
Auer G
Drury A.J
Karatsolis B.T
Lyu J
Betzler C
Eberli G.P
Kroon D.
Abstract
This study provides a Miocene-to-recent history of Tasman Leakage (TL), driving surface-to-intermediate waters from the Pacific into the Indian Ocean. TL, in addition to Indonesian ThroughFlow (ITF), constitutes an important part of the Southern Hemisphere Supergyre. Here, we employ deep-sea benthic δ13C timeseries from the southwestern Pacific and eastern Indian Oceans to identify the history of Tasman Leakage. The δ13C results combined with sedimentary evidence show that an inter-ocean connection south of Australia existed from 7 Ma onward. A southward shift in Westerlies combined with a northward movement of Australia created the oceanic corridor necessary for Tasman Leakage (between Australia and the sub-Antarctic Front) at this time. Furthermore, changes in the northern limb of the Supergyre (ITF) are evident in the sedimentary record on Broken Ridge from ∼3 to 2 Ma when Banda Sea intermediate waters started originating from the North Pacific. © 2021. The Authors.
Subjects
Australia; intermediate water; ITF; late Miocene; Southern Hemisphere Supergyre; Tasman Leakage
Other Subjects
Oceanography; Australia; Deep sea; Indian ocean; Indonesian throughflow; Intermediate waters; Late Miocene; Miocene; Southern Hemisphere; Southern hemisphere supergyre; Tasman leakage; Sedimentology; carbon isotope; deep-sea benthos; intermediate water; leakage; Miocene; oceanic front; Southern Hemisphere; surface water; throughflow; westerly; Australia; Banda Sea; Indian Ocean; Indonesian seas; Pacific Ocean; Pacific Ocean (North)
Type
journal article