Fumaroles Icelandic. Fumaroles may occur along tiny cracks or long fissures, in chaotic clusters or fields, and on the. These fumaroles are all at the foot of steep linear fractures which.

The bubbling and hissing geothermal area covers some 4 km2. Fumaroles may occur along tiny cracks or long fissures, in chaotic clusters or fields, and on the surfaces.