(Table 2) Radiocarbon ages of eastern equatorial Pacific sediment cores

We use planktonic oxygen isotope (d18O) records spanning the last 30,000 years (kyr) to constrain the magnitude and spatial pattern of glacial cooling in the upwelling environment of the eastern equatorial Pacific (EEP). Fourteen new downcore d18O records were obtained from surface-dwelling plankton...

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Bibliographic Details
Main Authors: Koutavas, Athanasios, Lynch-Stieglitz, Jean
Format: Dataset
Language:English
Published: PANGAEA 2003
Subjects:
Age
14C AMS
14C calibrated
CALIB 4.3 (Stuiver et al.
1998)
dated
difference error
Calendar age
maximum/old
minimum/young
DEPTH
sediment/rock
Elevation of event
Event label
Laboratory code/label
Latitude of event
Longitude of event
PC
Piston corer
RC08
RC08-102
RC11
RC1112
RC11-238
RC13
RC13-140
Robert Conrad
V19
V19-27
V19-28
V21
V21-29
V21-30
V21-40
Vema
Pacific
Planktonic foraminifera
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.841354
https://doi.org/10.1594/PANGAEA.841354
Description
Summary:We use planktonic oxygen isotope (d18O) records spanning the last 30,000 years (kyr) to constrain the magnitude and spatial pattern of glacial cooling in the upwelling environment of the eastern equatorial Pacific (EEP). Fourteen new downcore d18O records were obtained from surface-dwelling planktonic foraminifera Globigerinoides sacculifer and Globigerinoides ruber in eight cores from the upwelling tongue of the EEP. All sites have sedimentation rates exceeding 5 cm/kyr and, with one exception, lie above the modern depth of the foraminiferal lysocline. Sites directly underlying the cool band of upwelling immediately south of the equator record mean late Holocene (LH)-Last Glacial Maximum (LGM) d18O amplitudes ranging between 1.0 and 1.3 per mil. We estimate that mean sea surface temperatures (SST) in this region during the LGM were on average 1.5 ± 0.5°C lower than the LH. Larger d18O amplitudes are observed in sites north of the equator, indicating a spatial pattern of reduced meridional SST gradient across the equator during the LGM. This result is supported by comparison of Mg/Ca SST reconstructions from two sites straddling the equator. We interpret the reduction of this gradient during the LGM as evidence for a less intense cold tongue-Intertropical Convergence Zone (ITCZ) frontal system, a more southerly position of the ITCZ, and weaker southeast equatorial trades in the EEP.

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