image: Ice core scientist Logan Mitchell is shown marking the depth on an ice core at the West Antarctic Ice Sheet (WAIS) Divide ice core site. Air extracted from WAIS Divide ice core samples was used to reconstruct the methane interpolar gradient (IPG) which was used to constrain early anthropogenic methane emissions. This image relates to a paper that appeared in the 22 Nov., 2013, issue of Science, published by AAAS. The paper, by Logan Mitchell at Oregon State University in Corvallis, Ore., and colleagues was titled "Constraints on the Late Holocene Anthropogenic Contribution to the Atmospheric Methane Budget." view more
Credit: [Image courtesy of Logan Mitchell]