Increasing eolian dust deposition in the western United States linked to human activity

Nature Geoscience
By: , and 

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Abstract

Mineral aerosols from dust are an important influence on climate and on marine and terrestrial biogeochemical cycles. These aerosols are generated from wind erosion of surface soils. The amount of dust emission can therefore be affected by human activities that alter surface sediments. However, changes in regional- and global-scale dust fluxes following the rapid expansion of human populations and settlements over the past two centuries are not well understood. Here we determine the accumulation rates and geochemical properties of alpine lake sediments from the western interior United States for the past 5,000 years. We find that dust load levels increased by 500% above the late Holocene average following the increased western settlement of the United States during the nineteenth century. We suggest that the increased dust deposition is caused by the expansion of livestock grazing in the early twentieth century. The larger dust flux, which persists into the early twenty-first century, results in a more than fivefold increase in inputs of K, Mg, Ca, N and P to the alpine ecosystems, with implications for surface-water alkalinity, aquatic productivity and terrestrial nutrient cycling.

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Publication type Article
Publication Subtype Journal Article
Title Increasing eolian dust deposition in the western United States linked to human activity
Series title Nature Geoscience
DOI 10.1038/ngeo133
Volume 1
Year Published 2008
Language English
Publisher Nature
Contributing office(s) Geosciences and Environmental Change Science Center
Description 7 p.
First page 189
Last page 195
Country United States
State Colorado
Other Geospatial San Juan Mountains
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