Photograph by R.L. Christiansen on
27 July 1973
Fumarole
Fumaroles are vents from which volcanic gas escapes into
the atmosphere. Fumaroles may occur along tiny cracks or long fissures,
in chaotic clusters or fields, and on the surfaces of lava flows and
thick deposits of pyroclastic flows. They may persist for decades
or centuries if they are above a persistent heat source or disappear
within weeks to months if they occur atop a fresh volcanic deposit that
quickly cools.
Close view of a fumarole on Kilauea Volcano. Elemental sulfur
vapor escaping from the fumarole has cooled to form yellow-colored
crystals around its margins.