In this area, the hot springs mostly surround volcanos, and it is easy for the water to become infused with acidic volcanic gases, such as hydroged sulfide, sulfur dioxide and carbon dioxide. The water is usually near boiling and very acidic, and there is a strong smell of sulfur.
由於此區的溫泉露頭多分佈在火山四周，容易滲入大量的酸性火山氣體，如硫化氫、二氧化硫及二氧化碳等，所以泉質通常屬於強酸性，溫度接近沸點，有濃重的硫磺味。