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| Harada, Naomi; Sato, Miyako; Sakamoto, Tatsuhiko. |
| [1] We present records of phytoplankton-produced alkenones down a long piston core, which reveal changes of sea surface temperature (SST) and sea surface salinity (SSS) in the southwestern Okhotsk Sea over the past 120 ka. Between 20 and 60 ka B. P., alkenone-derived temperatures typically increased by 6 degrees C-8 degrees C from periods corresponding, within a few hundred years, to stadials to those corresponding to interstadials recorded in Greenland ice cores. The abundance of C-37:4 alkenone relative to total C37 alkenones (percent C-37:4), a possible proxy for salinity, indicated that during most low SSS was associated with high SST. The warm freshwater events might be related to ( 1) a decline in the supply of saline water entering the Okhotsk Sea... |
| Tipo: Text |
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| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34826/33302.pdf |
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| Harada, Naomi; Ninnemann, Ulysses; Lange, Carina B.; Marchant, Margarita E.; Sato, Miyako; Ahagon, Naokazu; Pantoja, Silvio. |
| We show environmental and nitrogen cycle changes between 13 and 2.5 kyr BP (from the latest deglaciation to the Holocene) based on biogeochemical records in a sediment core from the Pacific entrance of the Strait of Magellan. Organic carbon, total nitrogen, and C-37 alkenone contents were low during 13-9 kyr BP but increased rapidly at 8 kyr BP. The relative contribution of tetra-unsaturated C-37 alkenone, used as a salinity proxy, suggests low salinity during 13-9 kyr BP changing to high salinity at 8 kyr BP. Planktic foraminifer data showed that Globigerina bulloides was more abundant during the deglacial-early Holocene than in the mid-late Holocene, whereas abundances of Neogloboquadrina pachyderma showed the opposite pattern. This evidence plus... |
| Tipo: Text |
Palavras-chave: Biogenic components; Delta C-13; Delta N-15; Planktic foraminifera; Alkenone; Sea surface temperature; Southern Patagonia. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37548/36825.pdf |
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