Open AccessImpact of Weddell Sea shelf progradation on Antarctic bottom water formation during the Miocene
Author(s) -
Huang Xiaoxia,
Stärz Michael,
Gohl Karsten,
Knorr Gregor,
Lohmann Gerrit
Publication year - 2017
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1002/2016pa002987
Subject(s) - antarctic bottom water , geology , weddell sea bottom water , bathymetry , oceanography , ocean gyre , late miocene , progradation , bottom water , circumpolar deep water , continental shelf , ice shelf , sea ice , paleontology , north atlantic deep water , subtropics , thermohaline circulation , cryosphere , facies , structural basin , fishery , biology
The Weddell Sea is a main location of bottom water formation and, thus, an important component of global ocean circulation. In this study we examine the ocean and climatic responses to a shelf progradation induced by ice sheet advance and glacially transported sediments during the Miocene, using a general circulation model. Our investigations show that relative to a Miocene standard bathymetry, a farther southerly placed shelf break, as reconstructed in a state‐of‐the‐art bathymetry for the Weddell Sea, enables enhanced Antarctic Bottom Water (AABW) formation and gyre transport during the middle Miocene for both relatively high and low atmospheric CO 2 concentrations. Furthermore, CO 2 sensitivity experiments show that an atmospheric CO 2 decline for a setup with the southerly placed shelf break of a new bathymetry has only a minor impact on AABW formation, while the standard setup shows an increase. In combination, these impacts may explain the pronounced deep water formation in the southern high latitudes from the middle Miocene to the late Miocene.