Carbon isotope evidence for a northern source of deep water in the glacial western North Atlantic
| Autor: | Stephen A. Swift, Lloyd D Keigwin |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Water mass
Multidisciplinary 010504 meteorology & atmospheric sciences biology δ13C North Atlantic Deep Water Last Glacial Maximum Subtropics 010502 geochemistry & geophysics biology.organism_classification 01 natural sciences Foraminifera Oceanography Commentaries Physical Sciences Glacial period Hydrography Geology 0105 earth and related environmental sciences |
| Zdroj: | Proceedings of the National Academy of Sciences. 114:2831-2835 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | The prevailing view of western Atlantic hydrography during the Last Glacial Maximum (LGM) calls for transport and intermixing of deep southern and intermediate northern end members. However, δ13C and Δ14C results on foraminifera from a sediment core at 5.0 km in the northern subtropics show that there may have also been a northern source of relatively young, very dense, nutrient-depleted water during the LGM (18 ky to 21 ky ago). These results, when integrated with data from other western North Atlantic locations, indicate that the ocean was poorly ventilated at 4.2 km, with better ventilation above and below that depth. If this is a signal of water mass source and not nutrient storage, it would indicate that a previously unrecognized deep water end member originated along the western margin of the Labrador Sea, analogous to dense water formation today around Antarctica and in the Okhotsk Sea. |
| Databáze: | OpenAIRE |
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