Stable carbon and oxygen isotope record of planktonic foraminifera in ODP Site 138-851 ...

• Main Authors: Ravelo, Ana Christina, Shackleton, Nicholas J
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1995
• Subjects: Ocean Drilling Program ODP; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.807757; https://doi.pangaea.de/10.1594/PANGAEA.807757

This study investigates changes in the upper water column hydrography at Site 851 of the eastern tropical Pacific Ocean since the late Pliocene, using the oxygen and carbon isotopic composition of three species of planktonic foraminifers, each calcifying at different depths in the photic zone. The upper ocean seasonal hydrography in this region responds to the seasonally changing trade winds and thus is expected to respond to past changes in trade winds. One major change occurs at about 1.5 Ma, when the thermocline adjusts from a deep position to a shallower position. The thermocline remains in a relatively shallow position throughout the record up to recent time, with slight variations occurring synchronously with glacial/interglacial stages. In glacials, SSTs are probably a few degrees cooler and the thermocline is slightly deeper. From our knowledge of seasonal and interannual adjustments of the thermocline in this location, a deeper thermocline might be interpreted as either a decrease in the strength of ... : Supplement to: Ravelo, Ana Christina; Shackleton, Nicholas J (1995): Evidence for surface-water circulation changes at Site 851 in the eastern Tropical Pacific Ocean. In: Pisias, NG; Mayer, LA; Janecek, TR; Palmer-Julson, A; van Andel, TH (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 138, 503-514 ...