Eddy-correlation measurement of hydrothermal gases

In the first application of eddy correlation in a hydrothermal region, we m easured turbulent fluxes ranging between -17 and 13,500 g CO2 m(-2) d(-1) i n Yellowstone National Park (YNP). These turbulent fluxes are similar in ma gnitude to chamber measurements of diffuse fluxes in the region. Negative t urbulent fluxes due to vegetative uptake were measured in non-thermal regio ns. The flux footprint was used to compare turbulent with surface fluxes wi thin the source area of EC measurements, and turbulent fluxes were consiste nt within error to the spatial extrapolation of chamber measurements. EC is more representative than chamber techniques, providing a viable alternativ e to measuring gas emissions in volcanic and hydrothermal terrain.