| The acid
lake inside the volcano Kawah-Idjen is called " green crater
". It's the biggest : (700 m about), the deepest (200 m,
36 millions/ m3), it has lasted over 2 centuries and
it's the most acid too (pH minimum 0,18) - so says the sign !
Its température is between 20 and 40 °C depending on the
activity of the volcano and the rain. A limestone rock boils and melts in this mixture of sulfuric and hydrochoric acid. Some globuls of sulphur (1 mm in diameter) float on the surface. There is a major sulphur deposit on the South side of the lake. The highest temperature measured has been 224 °C (December 1998). It emits a lot of sulphur dioxyde. |
|
A
mine was opened there in 1968. A clever system of pipes (10
m long, 50 cm in diameter) allows the sulphur to be carried
as an orange liquid (115 °C) and it cristallizes yellow.
Informations from Jacques-Marie Bardintzeff |