Data/hora: 07/06/2024 02:56:32

Provedor de dados: | 5
País: | France
Título: | Climate variability and ice-sheet dynamics during the last three glaciations
Autores: | Obrochta, Stephen P.; Crowley, Thomas J.; Channell, James E. T.; Hodell, David A.; Baker, Paul A.; Seki, Arisa; Yokoyama, Yusuke.
Data: | 2014-11-15
Ano: | 2014
Palavras-chave: | Insolation; IRD; Heinrich Event; MIS 6; MIS 8; AMOC.
Resumo: | A composite North Atlantic record from DSDP Site 609 and IODP Site U1308 spans the past 300,000 years and shows that variability within the penultimate glaciation differed substantially from that of the surrounding two glaciations. Hematite-stained grains exhibit similar repetitive down-core variations within the Marine Isotope Stage (MIS) 8 and 4-2 intervals, but little cyclic variability within the MIS 6 section. There is also no petrologic evidence, in terms of detrital carbonate-rich (Heinrich) layers, for surging of the Laurentide Ice Sheet through the Hudson Strait during MIS 6. Rather, very high background concentration of iceberg-rafted debris (IRD) indicates near continuous glacial meltwater input that likely increased thermohaline disruption sensitivity to relatively weak forcing events, such as expanded sea ice over deepwater formation sites. Altered (sub)tropical precipitation patterns and Antarctic warming during high orbital precession and low 65 degrees N summer insolation appear related to high abundance of Icelandic glass shards and southward sea ice expansion. Differing European and North American ice sheet configurations, perhaps aided by larger variations in eccentricity leading to cooler summers, may have contributed to the relative stability of the Laurentide Ice Sheet in the Hudson Strait region during MIS 6.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00289/40050/38793.pdf

https://archimer.ifremer.fr/doc/00289/40050/38794.pdf

https://archimer.ifremer.fr/doc/00289/40050/38795.kml

DOI:10.1016/j.epsl.2014.09.004

https://archimer.ifremer.fr/doc/00289/40050/

Editor: | Elsevier Science Bv
Formato: | application/pdf
Fonte: | Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2014-11-15 , Vol. 406 , P. 198-212

Fonte:

2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license

info:eu-repo/semantics/openAccess

restricted use