Fig. 4: Changes in South Pacific temperature and ocean circulation over the last eight million years.
From: South Pacific sea surface temperature and global ocean circulation changes since the late Miocene
Temporal variation of a alkenone-based sea surface temperatures in the Eastern South Pacific Ocean (SSTUK’37; U1543/PS97-114-2; this study; yellow shading denotes warmer than modern conditions), b strength of the Antarctic Circumpolar Current (ACC) in the Central South Pacific (CSP) Ocean based on Zr/Rb ratios of site U1541 (Lamy et al.10; 5.3-8 Ma this study), c CaCO3 content at site U1543 based on XRF representing changes in deep water ventilation, d meridional SST gradients between the equatorial Pacific23 (ODP1337) and the Eastern South Pacific Ocean (U1543, this study), e computed global zonal and meridional SST gradients16, f simulated volume of the Antarctic Ice Sheet46 (AIS; reversed scale) and g reconstructed changes in global atmospheric pCO263,65. The thick smoothed records in b, c represent 100 kyr-binned records by averaging the SST data for every 100 kyrs in 50 kyr-overlapping windows. LMC late Miocene cooling, PTR Pliocene global temperature reversal, PWP Pliocene warm period, iNHG intensification of the Northern Hemisphere Glaciation, MPT mid-Pleistocene transition. Grey vertical bars denote periods of intensified ACC strength.
