Planktonic Mg/Ca and stable oxygen isotope ratios for DSDP Hole 90-590B
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| Auteurs principaux: | , , , |
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| Format: | Dataset Open Access |
| Langue: | en |
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PANGAEA
2011
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| _version_ | 1867167668542373888 |
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| author | Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter |
| author_facet | Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The transition from the early Pliocene "Warmhouse" towards the present "Icehouse" climate and the role of Gateway dynamics are intensively debated. Both, the constrictions of the Central American Seaway and the Indonesian Gateway affected ocean circulation and climate during the Pliocene epoch. Here, we use combined d18O and Mg/Ca ratios of planktonic foraminifera (marine protozoa) from surface and subsurface levels to reconstruct the thermal structure and changes in salinities from the Southwest Pacific Deep Sea Drilling Project (DSDP) Site 590B from 6.5 to 2.5 Ma. Our data suggest a gradual cooling of ~2 °C and freshening of the sea surface during ~4.6-4 Ma with an increased meridional temperature gradient between the West Pacific Warm Pool and the Southwest Pacific when the closing of the Central American Seaway reached a critical threshold. After ~ 3.5 Ma, the restricted Indonesian Gateway might have amplified the East Australian Current, allowing enhanced heat transport towards the Southwest Pacific with reduced meridional temperature gradients when the global climate gradually cooled. At the same time our data suggest a cooling and freshening of Subantarctic Mode Water (SAMW) or/and an increased northward flow of SAMW towards Site 590B, possibly a first step towards the present Antarctic Frontal System. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_786478 |
| institution | PANGAEA |
| language | en |
| publishDate | 2011 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Planktonic Mg/Ca and stable oxygen isotope ratios for DSDP Hole 90-590B Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter 90-590B; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg90; South Pacific/Tasman Sea/CONT RISE The transition from the early Pliocene "Warmhouse" towards the present "Icehouse" climate and the role of Gateway dynamics are intensively debated. Both, the constrictions of the Central American Seaway and the Indonesian Gateway affected ocean circulation and climate during the Pliocene epoch. Here, we use combined d18O and Mg/Ca ratios of planktonic foraminifera (marine protozoa) from surface and subsurface levels to reconstruct the thermal structure and changes in salinities from the Southwest Pacific Deep Sea Drilling Project (DSDP) Site 590B from 6.5 to 2.5 Ma. Our data suggest a gradual cooling of ~2 °C and freshening of the sea surface during ~4.6-4 Ma with an increased meridional temperature gradient between the West Pacific Warm Pool and the Southwest Pacific when the closing of the Central American Seaway reached a critical threshold. After ~ 3.5 Ma, the restricted Indonesian Gateway might have amplified the East Australian Current, allowing enhanced heat transport towards the Southwest Pacific with reduced meridional temperature gradients when the global climate gradually cooled. At the same time our data suggest a cooling and freshening of Subantarctic Mode Water (SAMW) or/and an increased northward flow of SAMW towards Site 590B, possibly a first step towards the present Antarctic Frontal System. |
| title | Planktonic Mg/Ca and stable oxygen isotope ratios for DSDP Hole 90-590B |
| topic | 90-590B; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg90; South Pacific/Tasman Sea/CONT RISE |
| url | https://doi.org/10.1594/PANGAEA.786478 |