CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Anthropogenic forcings on the surficial osmium cycle

Sebastien Rauch (Institutionen för bygg- och miljöteknik, Vatten Miljö Teknik) ; Bernhard Peucker-Ehrenbrink ; Malin E. Kylander ; Dominik J. Weiss ; Antonio Martinez-Cortizas ; David Heslop ; Carolina Olid ; Tim M. Mighall ; Harold F. Hemond
Environmental Science and Technology (1382-3124). Vol. 44 (2010), 3, p. 881-887.
[Artikel, refereegranskad vetenskaplig]

Osmium is among the least abundant elements in the Earth’s continental crust. Recent anthropogenic Os contamination of the environment from mining and smelting activities, automotive catalytic converter use, and hospital discharges has been documented. Here we present evidence for anthropogenic overprinting of the natural Os cycle using a ca. 7000-year record of atmospheric Os deposition and isotopic composition from an ombrotrophic peat bog in NW Spain. Preanthropogenic Os accumulation in this area is 0.10 ± 0.04 ng m−2 y−1. The oldest strata showing human influence correspond to early metal mining and processing on the Iberian Peninsula (ca. 4700−2500 cal. BP). Elevated Os accumulation rates are found thereafter with a local maximum of 1.1 ng m−2 y−1 during the Roman occupation of the Iberian Peninsula (ca. 1930 cal. BP) and a further increase starting in 1750 AD with Os accumulation reaching 30 ng m−2 y−1 in the most recent samples. Osmium isotopic composition (187Os/188Os) indicates that recent elevated Os accumulation results from increased input of unradiogenic Os from industrial and automotive sources as well as from enhanced deposition of radiogenic Os through increased fossil fuel combustion and soil erosion. We posit that the rapid increase in catalyst-equipped vehicles, increased fossil fuel combustion, and changes in land-use make the changes observed in NW Spain globally relevant.

Denna post skapades 2010-02-08. Senast ändrad 2015-07-01.
CPL Pubid: 111688


Läs direkt!

Länk till annan sajt (kan kräva inloggning)