Data/hora: 09/06/2024 05:38:00

Provedor de dados: | 5
País: | France
Título: | Paleoclimate in continental northwestern Europe during the Eemian and early Weichselian (125-97ka): insights from a Belgian speleothem
Autores: | Vansteenberge, Stef; Verheyden, Sophie; Cheng, Hai; Edwards, R. Lawrence; Keppens, Eddy; Claeys, Philippe.
Data: | 2016
Ano: | 2016
Resumo: | The last interglacial serves as an excellent time interval for studying climate dynamics during past warm periods. Speleothems have been successfully used for reconstructing the paleoclimate of last interglacial continental Europe. However, all previously investigated speleothems are restricted to southern Europe or the Alps, leaving large parts of northwestern Europe undocumented. To better understand regional climate changes over the past, a larger spatial coverage of European last interglacial continental records is essential, and speleothems, because of their ability to obtain excellent chronologies, can provide a major contribution. Here, we present new, high-resolution data from a stalagmite (Han-9) obtained from the Han-sur-Lesse Cave in Belgium. Han-9 formed between 125.3 and similar to aEuro parts per thousand aEuro-97aEuro-ka, with interruptions of growth occurring at 117.3-112.9 and 106.6-103.6aEuro-ka. The speleothem was investigated for its growth, morphology and stable isotope (delta C-13 and delta O-18) composition. The speleothem started growing relatively late within the last interglacial, at 125.3aEuro-ka, as other European continental archives suggest that Eemian optimum conditions were already present during that time. It appears that the initiation of Han-9 growth is caused by an increase in moisture availability, linked to wetter conditions around 125.3aEuro-ka. The delta C-13 and delta O-18 proxies indicate a period of relatively stable conditions after 125.3aEuro-ka; however, at 120aEuro-ka the speleothem delta O-18 registered the first signs of regionally changing climate conditions, being a modification of ocean source delta O-18 linked to an increase in ice volume towards the Marine Isotope Stage (MIS) 5e-5d transition. At 117.5aEuro-ka, drastic vegetation changes are recorded by Han-9 delta C-13 immediately followed by a cessation of speleothem growth at 117.3aEuro-ka, suggesting a transition to significantly dryer conditions. The Han-9 record covering the early Weichselian displays larger amplitudes in both isotope proxies and changes in stalagmite morphology, evidencing increased variability compared to the Eemian. Stadials that appear to be analogous to those in Greenland are recognized in Han-9, and the chronology is consistent with other European (speleothem) records. Greenland Stadial 25 is reflected as a cold/dry period within Han-9 stable isotope proxies, and the second interruption in speleothem growth occurs simultaneously with Greenland Stadial 24.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00421/53280/54323.pdf

DOI:10.5194/cp-12-1445-2016

https://archimer.ifremer.fr/doc/00421/53280/

Editor: | Copernicus Gesellschaft Mbh
Formato: | application/pdf
Fonte: | Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2016 , Vol. 12 , N. 7 , P. 1445-1458

Fonte:

Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License.

info:eu-repo/semantics/openAccess

restricted use