Dépôt numérique
RECHERCHER

1750 years of large rainfall events inferred from particle size at East Lake, Cape Bounty, Melville Island, Canada.

Lapointe, François, Francus, Pierre, Lamoureux, Scott F., Saïd, Mériem et Cuven, Stéphanie (2012). 1750 years of large rainfall events inferred from particle size at East Lake, Cape Bounty, Melville Island, Canada. Journal of Paleolimnology , vol. 48 . p. 159-173. DOI: 10.1007/s10933-012-9611-8.

Ce document n'est pas hébergé sur EspaceINRS.

Résumé

Annual grain-size variation was measured on the varved (annually laminated) lacustrine sediment from Cape Bounty East Lake using an innovative image analysis system. About 7100 images were acquired using a scanning electron microscope and processed to obtain measurement of particles from 2845 varves. Several particle-size distributions indices were calculated and can be linked to high-energy sedimentary facies. Moreover, the coarse grain size (98th percentile) of these high-energy facies is strongly correlated with summer rainfall (and also summer temperature) of instrumental data from nearby stations. Particle-size distributions show a similar trend through time, especially for the standard deviation and the 98th percentile. Climatic reconstruction suggests that Cape Bounty recently experienced an unprecedented increase of rainfall events since ~AD 1920. On the other hand, changes in varve thickness are weakly correlated with the particle-size distribution. Altogether, these results highlight the need to obtain annual grain-size data to identify a meteorological signal.

Type de document: Article
Mots-clés libres: Varves; Scanning electron microscope; Image analysis; Grain size; Paleoclimate; High-Arctic
Centre: Centre Eau Terre Environnement
Date de dépôt: 19 nov. 2020 21:13
Dernière modification: 19 nov. 2020 21:13
URI: https://espace.inrs.ca/id/eprint/10548

Actions (Identification requise)

Modifier la notice Modifier la notice