@misc{10481/94935,
year = {2012},
url = {https://hdl.handle.net/10481/94935},
abstract = {Messinian foraminiferal stable oxygen and carbon isotopes of the Montemayor-1 core
(Guadalquivir Basin, SW Spain) have been investigated. This record is exceptional to
study the Mediterranean Outflow Water (MOW) impact on the Atlantic meridional
overturning circulation (AMOC) and global climate during the Messinian because the core
is near the Guadalhorce Corridor, the last Betic gateway to be closed during the early
Messinian. Our results allow dating accurately its closure at 6.18 Ma. Constant benthic
d18O values, high difference between benthic and planktonic d18O, and low sedimentation
rates before 6.18 Ma indicate the presence of a two-layer water column, with bottom
winnowing due to an enhanced Mediterranean outflow current. The enhanced contribution
of dense MOW to the North Atlantic Ocean likely fostered the formation of North Atlantic
Deep Water (NADW). After 6.18 Ma, benthic d18O values parallel that of the global
glacioeustatic curve, the difference between benthic and planktonic d18O is low, and
sedimentation rates considerably increased. This indicates a good vertical mixing of the
water column, interruption of the MOW, and a dominant glacioeustatic control on the
isotopic signatures. According to the role of MOW in the modern Atlantic thermohaline
circulation, the reduction of the MOW after the closure of the Guadalhorce Corridor
might have resulted in a decreased NADW formation rate between 6.0 and 5.5 Ma
weakening the AMOC and promoting northern hemisphere cooling. After the Gibraltar
Strait opening, the restoration of the MOW and related salt export from the Mediterranean
could have promoted an enhanced NADW formation.},
title = {Impact of restriction of the Atlantic-Mediterranean gateway on the Mediterranean Outflow Water and eastern Atlantic circulation during the Messinian},
doi = {https://doi.org/10.1029/2012PA002309},
author = {Pérez Asensio, José Noel and Aguirre, Julio and Schmiedl, Gerhard and Civis, Jorge},
}