Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4
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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
2015
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| _version_ | 1867168566479945728 |
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| author | Studer, Anja S Sigman, Daniel M Martínez-García, Alfredo Benz, Verena Winckler, Gisela Kuhn, Gerhard Esper, Oliver Lamy, Frank Jaccard, Samuel L Wacker, Lukas Oleynik, Sergey Gersonde, Rainer Haug, Gerald H |
| author_facet | Studer, Anja S Sigman, Daniel M Martínez-García, Alfredo Benz, Verena Winckler, Gisela Kuhn, Gerhard Esper, Oliver Lamy, Frank Jaccard, Samuel L Wacker, Lukas Oleynik, Sergey Gersonde, Rainer Haug, Gerald H |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (d15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with d15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the d15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the d15Ndb changes are not the result of changing species composition. The pennate and centric assemblage d15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate d15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_848271 |
| institution | PANGAEA |
| language | en |
| publishDate | 2015 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4 Studer, Anja S Sigman, Daniel M Martínez-García, Alfredo Benz, Verena Winckler, Gisela Kuhn, Gerhard Esper, Oliver Lamy, Frank Jaccard, Samuel L Wacker, Lukas Oleynik, Sergey Gersonde, Rainer Haug, Gerald H ANT-XXVI/2; AWI_Paleo; Gravity corer (Kiel type); Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS75/072-4; PS75 BIPOMAC; SL; South Pacific Ocean In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (d15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with d15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the d15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the d15Ndb changes are not the result of changing species composition. The pennate and centric assemblage d15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate d15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials. |
| title | Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4 |
| topic | ANT-XXVI/2; AWI_Paleo; Gravity corer (Kiel type); Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS75/072-4; PS75 BIPOMAC; SL; South Pacific Ocean |
| url | https://doi.org/10.1594/PANGAEA.848271 |