Estimation of mercury emissions from geothermal activity in Japan

Mercury emissions from active volcanoes are of interest for estimating the volcanogenic contribution of mercury to the atmosphere. Mercury samples were collected from sulfur fumaroles in the large exhaling fields. Mercury concentrations in the fumarolic gases of twelve geothermal activity areas varied between 1.8 and 781 μ g/m3 with a geometrical mean 39.7 μ g/m3. With these analyses, yearly mercury output from geothermal fumarolic sources in Japan was estimated as 1.4 tons. The contribution to the environment of mercury released from geothermal areas in Japan was estimated as about 2%.