A research poster presenting data from gas sampling in Sherman Crater will be presented this week at the American Geophysical Union meeting in San Francisco. Written by Peter Kelley and his colleagues at Cascades Volcano Observatory and WWU, the poster compares fumarole composition data collected by the traditional evacuated glass flask method with data collected from a passive MultGAS ‘gas sniffer’ device Peter assembled. The sniffer was backpacked to the crater in 2011, where it sampled gas from ambient air while the MBVRC team collected gas in flasks. Learn more about gas sampling rationale and methods here on this website. The poster is permanently displayed here.
The sniffer was also deployed at the Crater Rock fumarole on Mount Hood. Gas compositions between the two methods were within 20% at Hood, but there was considerable disparity in gas compositions at Sherman Crater. At Baker, CO2/H2S ratios differed by 20-50%, and gas steam ratios were off by an order of magnitude. This could be due to errors in the flask collection method (although data were consistent with prior years’ sampling), an undetetected malfunction in the multiGAS sampler, or perhaps the automated sampler just wasn’t sitting in the best place at Baker. The experiment should be repeated at both volcanoes this coming year.