(Table 2) Radiocarbon ages of eastern equatorial Pacific sediment cores
Fuente:
PANGAEA
Enregistré dans:
| Auteurs principaux: | , |
|---|---|
| Format: | Dataset Open Access |
| Langue: | en |
| Publié: |
PANGAEA
2003
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1867170053060820992 |
|---|---|
| author | Koutavas, Athanasios Lynch-Stieglitz, Jean |
| author_facet | Koutavas, Athanasios Lynch-Stieglitz, Jean |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | 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. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_841354 |
| institution | PANGAEA |
| language | en |
| publishDate | 2003 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 2) Radiocarbon ages of eastern equatorial Pacific sediment cores Koutavas, Athanasios Lynch-Stieglitz, Jean Age, 14C AMS; Age, 14C calibrated, CALIB 4.3 (Stuiver et al., 1998); Age, dated; Age, difference error; Calendar age; Calendar age, maximum/old; Calendar age, 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 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. |
| title | (Table 2) Radiocarbon ages of eastern equatorial Pacific sediment cores |
| topic | Age, 14C AMS; Age, 14C calibrated, CALIB 4.3 (Stuiver et al., 1998); Age, dated; Age, difference error; Calendar age; Calendar age, maximum/old; Calendar age, 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 |
| url | https://doi.org/10.1594/PANGAEA.841354 |