Stable oxygen isotope and Mg/Ca ratios of planktonic foraminifera from the Caribbean and North Atlantic

• Main Authors: Schmidt, Matthew W, Spero, Howard J, Lea, David W
• Format: Dataset
• Language: English
• Published: PANGAEA 2004
• Subjects: 165-999A; also published as VM28-122; Caribbean Sea; DRILL; Drilling/drill rig; Joides Resolution; Leg165; Ocean Drilling Program; ODP; PC; Piston corer; V28; V28-122; Vema; North Atlantic Deep Water; North Atlantic; Planktonic foraminifera
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.716696; https://doi.org/10.1594/PANGAEA.716696

Variations in the strength of the North Atlantic Ocean thermohaline circulation have been linked to rapid climate changes during the last glacial cycle through oscillations in North Atlantic Deep Water formation and northward oceanic heat flux. The strength of the thermohaline circulation depends on the supply of warm, salty water to the North Atlantic, which, after losing heat to the atmosphere, produces the dense water masses that sink to great depths and circulate back south. Here we analyse two Caribbean Sea sediment cores, combining Mg/Ca palaeothermometry with measurements of oxygen isotopes in foraminiferal calcite in order to reconstruct tropical Atlantic surface salinity during the last glacial cycle. We find that Caribbean salinity oscillated between saltier conditions during the cold oxygen isotope stages 2, 4 and 6, and lower salinities during the warm stages 3 and 5, covarying with the strength of North Atlantic Deep Water formation. At the initiation of the Bølling/Allerød warm interval, Caribbean surface salinity decreased abruptly, suggesting that the advection of salty tropical waters into the North Atlantic amplified thermohaline circulation and contributed to high-latitude warming.