Standing in steaming acid water (pH 1 to 2) while being subjected to horizontally driven sleet   -   a hot and cold start to the tour in Kyushu, Japan.

Members of the tour group in the alunite zone on the margins of the Kuju Iwo-yama active high sulphidation, high temperature fumarolic field.

This was the first of the three active hydrothermal areas visited on the first day.   The other two were the Komatsu-ike steaming ground where magmatic, high sulphidation hydrothermal acitivity is progressing in a low sulphidation hydrothermal field adjacent to the Hatchobaru geothermal power plant, and the argillic alteration zone adjacent to the low sulphidation geothermal power plant.
Photograph by Mike Porter.