hot boiling mud at fumarole inside the crater of the active volcano

active area ash background beautiful big boil boiling bubbling caldera crater east environment eruption exploding fast fumarola fumarole gas geology geothermal geyser gray grey heat hot hverir iceland inside kamchatka lava magma mineral mountain mud muddy mutnovka mutnovsky national nature outdoor park photographed produces russia sculpture shutter smell smoke speed steam sulfur the thermal tourism travel trekking volcanic volcano wild