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| Ronge, Thomas A.; Prange, M.; Mollenhauer, Gesine; Ellinghausen, Maret; Kuhn, G.; Tiedemann, R.. |
| It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial‐interglacial atmospheric CO2‐levels. So far however, ventilation records from the Indian sector of the Southern Ocean, are widely missing. Here we present reconstructions of water residence times (depicted as ΔΔ14C and Δδ13C) for the last 32,000 years on sediment records from the Kerguelen Plateau and the Conrad Rise (~570‐2500 m water depth), along with simulated changes in ocean stratification from a transient climate model experiment. Our data indicate that Circumpolar Deep Waters in the Indian Ocean were part of the glacial carbon pool. At our sites, close to or bathed by upwelling deep‐waters, we find two pulses of decreasing ΔΔ14C and δ13C values... |
| Tipo: Text |
Palavras-chave: Radiocarbon; Ventilation; Southern Ocean; Younger Dryas; Carbon cycle; Indian Ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00611/72351/71258.pdf |
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| Ronge, T. A.; Tiedemann, R.; Lamy, F.; Koehler, P.; Alloway, B. V.; De Pol-holz, R.; Pahnke, K.; Southon, J.; Wacker, L.. |
| During the last deglaciation, the opposing patterns of atmospheric CO2 and radiocarbon activities (Delta C-14) suggest the release of C-14-depleted CO2 from old carbon reservoirs. Although evidences point to the deep Pacific as a major reservoir of this C-14-depleted carbon, its extent and evolution still need to be constrained. Here we use sediment cores retrieved along a South Pacific transect to reconstruct the spatio-temporal evolution of Delta C-14 over the last 30,000 years. In similar to 2,500-3,600 m water depth, we find C-14-depleted deep waters with a maximum glacial offset to atmospheric (14)(C) (Delta Delta C-14 = -1,000%). Using a box model, we test the hypothesis that these low values might have been caused by an interaction of aging and... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53251/54716.pdf |
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| Maier, E.; Meheust, M.; Abelmann, A.; Gersonde, R.; Chapligin, B.; Ren, J.; Stein, R.; Meyer, H.; Tiedemann, R.. |
| The glacial-to-Holocene evolution of subarctic Pacific surface water stratification and silicic acid (Si) dynamics is investigated based on new combined diatom oxygen (delta O-18(diat)) and silicon (delta Si-30(diat)) isotope records, along with new biogenic opal, subsurface foraminiferal delta O-18, alkenone-based sea surface temperature, sea ice, diatom, and core logging data from the NE Pacific. Our results suggest that delta O-18(diat) values are primarily influenced by changes in freshwater discharge from the Cordilleran Ice Sheet (CIS), while corresponding delta Si-30(diat) are primarily influenced by changes in Si supply to surface waters. Our data indicate enhanced glacial to mid Heinrich Stadial 1 (HS1) NE Pacific surface water stratification,... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00351/46254/46083.pdf |
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| Bonizzoni, Mariangela; Bourjea, Jerome; Chen, Bin; Crain, B. J.; Cui, Liwang; Fiorentino, V.; Hartmann, S.; Hendricks, S.; Ketmaier, V.; Ma, Xiaoguang; Muths, Delphine; Pavesi, L.; Pfautsch, S.; Rieger, M. A.; Santonastaso, T.; Sattabongkot, Jetsumon; Taron, C. H.; Taron, D. J.; Tiedemann, R.; Yan, Guiyun; Zheng, Bin; Zhong, Daibin. |
| This article documents the addition of 92 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anopheles minimus, An. sinensis, An. dirus, Calephelis mutica, Lutjanus kasmira, Murella muralis and Orchestia montagui. These loci were cross-tested on the following species: Calephelis arizonensi, Calephelis borealis, Calephelis nemesis, Calephelis virginiensis and Lutjanus bengalensis. |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00042/15373/13513.pdf |
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| Max, L.; Rippert, N.; Lembke-jene, L.; Mackensen, A.; Nürnberg, D.; Tiedemann, R.. |
| We provide high-resolution foraminiferal stable carbon isotope (delta C-13) records from the subarctic Pacific and Eastern Equatorial Pacific (EEP) to investigate circulation dynamics between the extratropical and tropical North Pacific during the past 60 kyr. We measured the delta C-13 composition of the epibenthic foraminiferal species Cibicides lobatulus from a shallow sediment core recovered from the western Bering Sea (SO201-2-101KL; 58 degrees 52.52' N, 170 degrees 41.45' E; 630 m water depth) to reconstruct past ventilation changes close to the source region of Glacial North Pacific Intermediate Water (GNPIW). Information regarding glacial changes in the delta C-13 of subthermocline water masses in the EEP is derived from the deep-dwelling... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53196/54997.pdf |
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| Caniupan, M.; Lamy, F.; Lange, C. B.; Kaiser, J.; Arz, H.; Kilian, R.; Baeza Urrea, O.; Aracena, C.; Hebbeln, D.; Kissel, C.; Laj, C.; Mollenhauer, G.; Tiedemann, R.. |
| Glacial millennial-scale paleoceanographic changes in the Southeast Pacific and the adjacent Southern Ocean are poorly known due to the scarcity of well-dated and high resolution sediment records. Here we present new surface water records from sediment core MD07-3128 recovered at 53 degrees S off the Pacific entrance of the Strait of Magellan. The alkenone-derived sea surface temperature (SST) record reveals a very strong warming of ca. 8 C over the last Termination and substantial millennial-scale variability in the glacial section largely consistent with our planktonic foraminifera oxygen isotope (delta(18)O) record of Neogloboquadrina pachyderma (sin.). The timing and structure of the Termination and some of the millennial-scale SST fluctuations are... |
| Tipo: Text |
Palavras-chave: Patagonian Ice Sheet; Alkenones; Ice rafted debris; Millennial-scale changes; Southeast Pacific. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00214/32516/31000.pdf |
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