(Table 1) Age determination of sediment core MD99-2284
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| Autori principali: | , , , , |
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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
2013
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| _version_ | 1867170963802554368 |
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| author | Dokken, Trond Nisancioglu, Kerim H Li, Camille Battisti, David S Kissel, Catherine |
| author_facet | Dokken, Trond Nisancioglu, Kerim H Li, Camille Battisti, David S Kissel, Catherine |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Dansgaard-Oeschger (D-O) cycles are the most dramatic, frequent, and wide-reaching abrupt climate changes in the geologic record. On Greenland, D-O cycles are characterized by an abrupt warming of 10 ± 5°C from a cold stadial to a warm interstadial phase, followed by gradual cooling before a rapid return to stadial conditions. The mechanisms responsible for these millennial cycles are not fully understood but are widely thought to involve abrupt changes in Atlantic Meridional Overturning Circulation due to freshwater perturbations. Here we present a new, high-resolution multiproxy marine sediment core monitoring changes in the warm Atlantic inflow to the Nordic seas as well as in local sea ice cover and influx of ice-rafted debris. In contrast to previous studies, the freshwater input is found to be coincident with warm interstadials on Greenland and has a Fennoscandian rather than Laurentide source. Furthermore, the data suggest a different thermohaline structure for the Nordic seas during cold stadials in which relatively warm Atlantic water circulates beneath a fresh surface layer and the presence of sea ice is inferred from benthic oxygen isotopes. This implies a delicate balance between the warm subsurface Atlantic water and fresh surface layer, with the possibility of abrupt changes in sea ice cover, and suggests a novel mechanism for the abrupt D-O events observed in Greenland ice cores. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_820939 |
| institution | PANGAEA |
| language | en |
| publishDate | 2013 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 1) Age determination of sediment core MD99-2284 Dokken, Trond Nisancioglu, Kerim H Li, Camille Battisti, David S Kissel, Catherine 3664N/S; Age, 14C AMS; Age, 14C calibrated; Age, dated; Age, dated, standard deviation; Age, maximum/old; Age, minimum/young; Age model; Calendar age; CALYPSO; Calypso Corer; DEPTH, sediment/rock; IMAGES V; Marion Dufresne (1995); MD114; MD99-2284; N. Shetland channel; Sample ID Dansgaard-Oeschger (D-O) cycles are the most dramatic, frequent, and wide-reaching abrupt climate changes in the geologic record. On Greenland, D-O cycles are characterized by an abrupt warming of 10 ± 5°C from a cold stadial to a warm interstadial phase, followed by gradual cooling before a rapid return to stadial conditions. The mechanisms responsible for these millennial cycles are not fully understood but are widely thought to involve abrupt changes in Atlantic Meridional Overturning Circulation due to freshwater perturbations. Here we present a new, high-resolution multiproxy marine sediment core monitoring changes in the warm Atlantic inflow to the Nordic seas as well as in local sea ice cover and influx of ice-rafted debris. In contrast to previous studies, the freshwater input is found to be coincident with warm interstadials on Greenland and has a Fennoscandian rather than Laurentide source. Furthermore, the data suggest a different thermohaline structure for the Nordic seas during cold stadials in which relatively warm Atlantic water circulates beneath a fresh surface layer and the presence of sea ice is inferred from benthic oxygen isotopes. This implies a delicate balance between the warm subsurface Atlantic water and fresh surface layer, with the possibility of abrupt changes in sea ice cover, and suggests a novel mechanism for the abrupt D-O events observed in Greenland ice cores. |
| title | (Table 1) Age determination of sediment core MD99-2284 |
| topic | 3664N/S; Age, 14C AMS; Age, 14C calibrated; Age, dated; Age, dated, standard deviation; Age, maximum/old; Age, minimum/young; Age model; Calendar age; CALYPSO; Calypso Corer; DEPTH, sediment/rock; IMAGES V; Marion Dufresne (1995); MD114; MD99-2284; N. Shetland channel; Sample ID |
| url | https://doi.org/10.1594/PANGAEA.820939 |