Bubbling mud pools and geothermal ground on Krafla mountain near Myvatn, Iceland, Polar Regions

iceland geothermal geology plate tectonics tectonic hot earth ground mineral minerals steam steaming hot spring hot springs mud mud pool pool bubbling boiling boil grey muddy myvatn solfataras day outdoors landscape landscapes nature natural world volcanic landscapes mud pools physical geography surface processes polar regions mount krafla krafla horizontal