Ice core record of dust sources in the western United States over the last 300 years

Over the past ~ 5000 years, amplified dust generation and deposition in the American West has been linked to human activity. In recent decades, intensified rates of agriculture and livestock grazing have been correlated with greater dust production detected on seasonal to annual timescales. The comb...

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Bibliographic Details
Published in:Chemical Geology
Main Authors: Aarons, S, Aciego, S, Gabrielli, P, Koornneef, J, Uglietti, C, Wegner, A, Blakowski, M, Bouman, C., DELMONTE, BARBARA
Other Authors: Delmonte, B, Bouman, C
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier B.V. 2016
Subjects:
Dust
Dust cycle
Ice core
Midlatitude glacier
Paleoclimate
Radiogenic isotope
Trace element
ice core
Online Access:http://hdl.handle.net/10281/132452
https://doi.org/10.1016/j.chemgeo.2016.09.006
http://www.sciencedirect.com/science/journal/00092541
Description
Summary:Over the past ~ 5000 years, amplified dust generation and deposition in the American West has been linked to human activity. In recent decades, intensified rates of agriculture and livestock grazing have been correlated with greater dust production detected on seasonal to annual timescales. The combination of land use intensification and climate change (i.e. increased drought frequency) in North America highlights the importance of characterizing the sources of dust both before and after the influence of anthropogenic activity. We apply high-precision geochemical and isotopic (Sr and Nd isotopes) techniques to an ice core from the Upper Fremont Glacier (Wyoming, USA) to produce the first glacial dataset from the American West. Our Sr-Nd isotopic composition data indicates the evolving dust provenance to the Upper Fremont Glacier (UFG) from a long-range transport of mineral dust to a local source. This increasing input of dust from a local source is supported by a rise in average dust particle diameter combined with greater average dust concentration throughout the record. The greater presence of dust particles smaller than 2.5 μm in the most recent samples from UFG ice core record support existing satellite and sediment core data regarding the effects of anthropogenic activity upon dust sources and pathways in the American West. Although the Sr-Nd isotope database in North America needs be expanded, our results provide a survey of windborne dust through the past 270 years.

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