Cutting-Edge Research
in Kyoto University


Does Water Come from the Deep Earth? Geochemical investigation of hot-springs originating from deep fluid.

Density measurements for saline hot-spring water sampled from Arima,
seawater, and tap water using a float type densimeter

The existence of hot-spring waters of high salinity was well known in nonvolcanic regions, but their origin has been unknown for a long time. We began our geochemical investigation of hot-spring waters discharged in the non-volcanic regions of the southwestern part of Japan in 2003. Through our studies we expect to find hot-spring waters derived from deep fluid characterized by CO2-bearing saltwater, such as Arima-type thermal water, which originates from dehydrated metamorphic fluid released from the Philippine-Sea plate subducting into the interior of the earth.

Shinji Ohsawa, PhD
Professor, Beppu Geothermal Research Laboratory,
Graduate School of Science