Fluid Flow Processes in the Beppu Geothermal System, Japan

Abstract

The Beppu geothermal system comprises two out-flow zones on the east side of a high temperature resource area situated beneath the volcanoes o-f Tsurumi and Garandake. The deep geothermal fluid is inferred to have a temperature o-f at least 250 - 300 ?C and a chloride concentration of at least 1400 - 1600 mg/kg. The chemical and physical differences between the fluids in the two outflow zones are due to differences in the way the fluid rises from beneath the volcanoes. Fluids in the outflow zone have evolved from the predominantly by dilution with However the northern, Kamegawa, dominated by steam loss from the ,__.. Ñ the formation of steam-heated groundwaters at shallow depth.