Ventilation and expansion of intermediate and deep waters in the Southeast Pacific during the last termination

Type Article
Date 2020-07
Language English
Author(s) Haddam N. A.1, 2, Michel E.2, Siani G.1, Licari L.3, Dewilde F.2
Affiliation(s) 1 : GEOPS Géosciences Paris‐Sud, CNRS, Université de Paris Sud Paris Saclay Orsay Cedex ,France
2 : LSCE/IPSL Laboratoire des Sciences du Climat et de l’Environnement, CEA‐CNRS‐UVSQ, Orme des Merisiers Saint‐Aubin, France
3 : Centre Européen de Recherche de d’Enseignement des Géosciences de l’Environnement, CNRS, Université d’Aix‐Marseille, Europôle Méditerranéen de l’Arbois Aix‐en‐Provence cedex 04, France
Source Paleoceanography And Paleoclimatology (2572-4517) (American Geophysical Union (AGU)), 2020-07 , Vol. 35 , N. 7 , P. e2019PA003743 (16p.)
DOI 10.1029/2019PA003743
WOS© Times Cited 2
Abstract

We investigate the geometry and ventilation of the water masses within bathyal depths (~1500 – ~2500 m) of the Southeast Pacific (SEP), inferring the lower depth limit variations of the Antarctic Intermediate Water (AAIW) since ~22 kyr cal. BP. We use three cores collected at the upper limit of the Pacific Deep Waters, between 41°S and 49°S and one core at a greater depth within this same water mass, at 46°S. The benthic foraminiferal assemblages and carbon and oxygen isotopes are used to show strong linkages between the timing of the deglacial Southern Ocean upwelling events and changes in the vertical extension and ventilation of the AAIW. In accordance with local/sub‐local oxygen reconstructions, we propose at least 3 states of ventilation–AAIW vertical extension; i) the late glacial and the Antarctic Cold Reversal (ACR): AAIW depth‐limit shoals, as its formation zone moves northward, ii) the deglaciation (excluding the ACR): the [O2] enrichment of the AAIW and the dominance of benthic species Trifarina angulosa indicate ventilated AAIW, along with a deepening of its lower limit, iii) the Holocene: enhanced influence of the Pacific Deep Water at bathyal depths (1500‐2500 m) in the SEP north of ~46°S, and the Circumpolar Deep Water south of ~46°S.

Full Text
File Pages Size Access
Publisher's official version 41 3 MB Open access
Supporting Information S1 10 1 MB Open access
Table S1 17 KB Open access
Table S2 58 KB Open access
Top of the page