hot grey mud stream in an orange sulfuric soil fissure in hverir, myvatn geothermal area in iceland

area boiling colorful crack crater crevasse field fissure flow formation fumarole geology geothermal grey hole hot spring hverarapara hverir iceland icelandic lake land landmark landscape mineral moon mountain mud myvatn natural nature orange red river rock simmering smoke soil solfataras steam stream sulfur sulphating sulphur tourist vent volcanic water sulfuric iceland