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| Russon, T.; Elliot, M.; Sadekov, A.; Cabioch, G.; Correge, T.; De Deckker, P.. |
| The position of the southern boundary of the Pacific warm pool is shown to have been stable since the early Pleistocene, based upon a planktic foraminiferal Mg/Ca-derived reconstruction of subtropical sea surface temperature in the Coral Sea. This contrasts with previous reconstructions showing warm pool contraction from the north and east and means that the early Pleistocene warm pool was more hemispherically asymmetric than its present configuration. The latter was not established until similar to 1Ma, supporting a strengthening of the northern Hadley Cell, which was not replicated in its southern counterpart, prior to the Mid-Pleistocene Transition. |
| Tipo: Text |
Palavras-chave: Pacific warm pool; Mg/Ca paleothermometry; Mid-Pleistocene Transition. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00144/25527/23672.pdf |
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| De Deckker, P.; Moros, M.; Perner, K.; Blanz, T.; Wacker, L.; Schneider, R.; Barrows, T.t.; O’loingsigh, T.; Jansen, E.. |
| The Quaternary is well known for being a period of the geological record that saw significant and alternating climatic fluctuations. Here, we concentrate on the last 94 millennia that saw Australia and its surrounding seas undergo significant environmental changes. Importantly also it is during that this period of time includes the arrival and settlement of humans in Australia. Following on from Marine Isotopic Stage 4 (MIS4) that saw, over the period of 71-59 ka BP, a significant eustatic sea level drop (similar to 100 m), low sea-surface temperatures as well as glacial conditions on land, Australia experienced wet conditions again, but eventually progressively entered into a glacial phase. By then, humans had arrived on this large continent and later the... |
| Tipo: Text |
Palavras-chave: Oceanic fronts; Leeuwin Current; Foraminifer faunal analysis; Marine isotopic stages; Last Glacial Maximum; Palaeoceanography; Sea-surface temperature; Moraines; Modern analogue technique; Subantarctic Front; G. ruber. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00657/76931/78127.pdf |
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| Bayon, Germain; Delvigne, C.; Ponzevera, Emmanuel; Borges, A. V.; Darchambeau, F.; De Deckker, P.; Lambert, T.; Monin, L.; Toucanne, Samuel; Andre, L.. |
| The δ30Si stable isotopic composition of silicon in soils and fine-grained sediments can provide insights into weathering processes on continents, with important implications on the Si budget of modern and past oceans. To further constrain the factors controlling the distribution of Si isotopes in sediments, we have analysed a large number (n=50) of separate size-fractions of sediments and suspended particulate materials collected near the mouth of rivers worldwide. This includes some of the world’s largest rivers (e.g. Amazon, Congo, Mackenzie, Mississippi, Murray-Darling, Nile, Yangtze) and rivers from the case study areas of the Congo River Basin and Northern Ireland. Silt-size fractions exhibit a mean Si isotopic composition (δ30Si = -0.21 ± 0.19‰; 2... |
| Tipo: Text |
Palavras-chave: World rivers; Congo basin; Northern Ireland; Si isotopes; Clay minerals; Weathering; Temperature; Precipitation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00434/54609/55991.pdf |
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| Russon, T.; Elliot, M.; Sadekov, A.; Cabioch, G.; Correge, T.; De Deckker, P.. |
| Reconstructions of subtropical southwest Pacific climate variability over the Pleistocene were derived from coupled planktic foraminiferal δ18O-Mg/Ca measurements taken from a southern Coral Sea sediment core. A clear shift from ∼40 kyr to ∼100 kyr modes of reconstructed glacial-interglacial sea surface temperature (SST) variability is seen over the mid-Pleistocene transition, and these fluctuations are shown to have remained coherent with the orbital obliquity cycle across the transition. The likely origin of this strong obliquity signal in subtropical southwest Pacific SST is shown to be the southern high latitudes, and comparison with existing SST reconstructions from the equatorial Pacific is consistent with the communication of the signal occurring... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00141/25187/23293.pdf |
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| Russon, T.; Elliot, M.; Kissel, C.; Cabioch, G.; De Deckker, P.; Correge, T.. |
| The modern delta(13)C(DIC) distribution in southwest subtropical Pacific deep waters is consistent with a regional mixing regime between water masses of open Pacific Ocean and Tasman Sea origin. This mixing regime is reconstructed across the middle-late Pleistocene using a record of benthic foraminiferal delta(13)C in a sediment core from the New Caledonia Trough. The relative influence on the mixing regime from open Pacific Ocean deep waters is seen to be significantly reduced during glacial in comparison to interglacial stages over the past 1.1 Ma. The spatial delta(13)C gradient in the Southern Ocean between deep waters entering the Tasman Sea and the open Pacific Ocean is shown to be consequently greater during glacial than interglacial stages but was... |
| Tipo: Text |
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| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00144/25522/23666.pdf |
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| Pelejero, C.; Calvo, E.; Barrows, T. T.; Logan, G. A.; De Deckker, P.. |
| Alkenone palaeothermometry has demonstrated a wide spatial and temporal applicability for the reconstruction of sea-surface temperatures (SST). Some oceanic realms, however, remain poorly studied. We document U-37(K) index data for two sediment cores retrieved from the South Tasman Sea, one west of New Zealand (SO136-GC3) and the other southeast of Tasmania (FR1/94-GC3), extending back 280 kyr BP for the former and 460 kyr BP for the latter. High climatic sensitivity on orbital time scales is observed at both locations, particularly west of New Zealand, where typical glacial/interglacial SST amplitudes always span more than 7 degrees C. Southeast of Tasmania, SST amplitudes are lower in amplitude (4.3 to 6.9 degrees C) with the exception of Termination IV,... |
| Tipo: Text |
Palavras-chave: SST; South Pacific Ocean; Molecular biomarker; Late Pleistocene; U-37(K); Marine Isotopic Stage 11. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34530/33425.pdf |
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