Tuesday, March 25, 2014

Evidence of Little Ice Age Related Strong Storms in Brazil

Evidence of strong storm events possibly related to the little Ice Age in sediments on the southerncoast of Brazil

Authors:

Oliveira et al

Abstract:

Late Holocene environmental changes on the southeastern Brazilian coast were assessed using a high-resolution paleoproductivity proxy record from a sediment core collected at 14 m water depth in the Pântano do Sul Inlet. Mollusk shells from the core were AMS dated, and sediment grain size, concentrations of organic carbon and total nitrogen, and δ13C and δ15N values were determined to investigate changes in paleoceanographic and paleoclimatic conditions over the depositional period. Most of the parameters showed strong fluctuations in the depth interval corresponding to the Little Ice Age, between 1560 and 1700 AD, that were marked by first an increase and then a decrease of input of terrigenous sediments to the inlet. Proxies also indicate that sedimentary conditions were more stable, before and after this period. The strong sedimentary changes observed in the Pântano do Sul Inlet may be related to climatic changes reported elsewhere in South America during 1550 and 1800 AD and to severe storm events associated with the enhanced cold fronts that occurred in the southern littoral region during this period.

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