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| Blumberg, S.; Lamy, F.; Arz, H. W.; Echtler, H. P.; Wiedicke, M.; Haug, G. H.; Oncken, O.. |
| The active plate margin of South America is characterized by a frequent occurrence of large and devastating subduction earthquakes. Here we focus on marine sedimentary records off Southern Chile that are archiving the regional paleoseismic history over the Holocene and Late Pleistocene. The investigated records - Ocean Drilling Program (ODP) Site 1232 and SONNE core 50SL - are located at similar to 40 degrees S and similar to 38 degrees S, within the Peru-Chilc trench, and are characterized by frequent interbedded strata of turbiditic and hemipelagic origin. On the basis of the sedimentological characteristics and the association with the active margin of Southern Chile, we assume that the turbidites are mainly scismically triggered, and may be considered... |
| Tipo: Text |
Palavras-chave: Turbidite frequency; Earthquake recurrence; Chile active margin; Trench deposits; Paleoseismology; Paleoclimate. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34850/33217.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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| Bertrand, S.; Hughen, K. A.; Lamy, F.; Stuut, J. -b. W.; Torrejon, F.; Lange, C. B.. |
| Glaciers are frequently used as indicators of climate change. However, the link between past glacier fluctuations and climate variability is still highly debated. Here, we investigate the mid- to late-Holocene fluctuations of Gualas Glacier, one of the northernmost outlet glaciers of the Northern Patagonian Icefield, using a multi-proxy sedimentological and geochemical analysis of a 15 m long fjord sediment core from Golfo Elefantes, Chile, and historical documents from early Spanish explorers. Our results show that the core can be sub-divided into three main lithological units that were deposited under very different hydrodynamic conditions. Between 5400 and 4180 cal yr BP and after 750 cal yr BP, sedimentation in Golfo Elefantes was characterized by the... |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00274/38496/36958.pdf |
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| Martinez-mendez, G.; Hebbeln, D.; Mohtadi, M.; Lamy, F.; De Pol-holz, R.; Reyes-macaya, D.; Freudenthal, Tim. |
| The Antarctic Intermediate Water (AAIW) is a key player in global-scale oceanic overturning processes and an important conduit for heat, fresh water, and carbon transport. The AAIW past variability is poorly understood mainly due to the lack of sedimentary archives at intermediate water depths. We present records of benthic stable isotopes from sediments retrieved with the seafloor drill rig MARUM-MeBo at 956m water depth off northern Chile (GeoB15016, 27 degrees 29.48S, 71 degrees 07.58W) that extend back to 970ka. The sediments at this site are presently deposited at the boundary between AAIW and Pacific Deep Water (PDW). For previous peak interglacials, our results reveal similar benthic C-13 values at site GeoB15016 and of a newly generated stack of... |
| Tipo: Text |
Palavras-chave: Paleoceanography; AAIW; Advection changes. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00263/37459/35821.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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