Sherman Crater fumarole gases have traditionally been sampled by evacuated glass flasks. A passive multiGAS sampling system was built by Peter Kelly at CVO, and deployed at Sherman Crater in 2011. This system collects and analyzes compositions of H2O, CO2, H2S, and SO2. At the same time, gases were sampled using the glass flasks. A comparison of the data is presented in this research poster (Kelly and others, 2012), and presented at the AGU meeting in December, 2012. Fumarole compositions analysed by the passive multiGAS ‘sniffer’ were quite different from those obtained by laboratory analysis of gas samples packed down from the crater in the glass flasks. However, the same comparative study done at Mount Hood the same year showed more nearly similar gas concentrations. Read about why fumarole sampling is done at Sherman Crater, see photos , and learn more about the methods here.