Pohutu geyser erupting steaming water from sulphurous mud and rock in Te Puia, Whakarewarewa Thermal Reserve in geothermal valley, Rotorua, North Island, New Zealand, Pacific

January 24, 2012 - Yellow sulphurous deposits resulting from degassing coating scoria cone formed during eruption on Nyamuragira Volcano, Democratic Republic of Congo.

The Blue Crater Lake of Viti, which appeared after an eruption in 1875, part of the sulphurous geothermal area of Namafjall, Reykjahlio, Iceland

Sulphurous fumaroles and volcanic strata in Tompaluan active crater on the flank of Mount Lokon, a volcano near Tomohon city, Gunung Lokon, Tomohon, North Sulawesi, Indonesia, Southeast Asia, Asia Indonesia

Steam issuing from sulphurous fumarole at Gran Craters, Vulcano Island, with islands of Lipari and Salina beyond, Aeolian Islands (Eolian Islands) (Lipari Islands), UNESCO World Heritage Site, Sicily, Italy, Mediterranean, Europe

Ethiopia; Afar region; Danakil Desert; Danakil Depression; Dallol geothermal area; hot sulfur springs; cone-like formation in intense yellow, red and green tones

Puente del Inca, rock arch and old thermal bath of the sulphur spring above the Rio de las Cuevas, near Uspallata, Mendoza Province, Argentina, South America

Bumpass hell sulphur area at Lassen Volcanic National Park, northern California, USA

Thermal spring in Saturnia with sulphur-containing water of the Monte Amiata Manciano Toskana Italien

Sulphure formations, Dallol, Danakil Depression, Ethiopia, Africa

Sulphure formations, Dallol, Danakil Depression, Ethiopia, Africa

360 panorama with the green sulphurous Emerald Lakes and volcanio Mt Tongariro, Tongariro National Park, Manawatu-Wanganui, North Island, New Zealand, Oceania

360 panorama with the green sulphurous Emerald Lakes and volcanio Mt Tongariro, Tongariro National Park, Manawatu-Wanganui, North Island, New Zealand, Oceania

Krafla volcanic area, sulfur springs, Leirhnjúkur, Reykjahlíð, Mývatni, Island

Emerald Lakes, crater lakes, volcanic landscape, Tongariro Alpine Crossing, Tongariro National Park, North Island, New Zealand, Oceania

Krafla volcanic area, sulfur springs, Leirhnjúkur, Reykjahlíð, Mývatni, Island

Crater lake of Kawah Ijen, Kawah Ijen, Jawa Timur, Java, Indonesia, Asia

Puente del Inca, old thermal bath of the sulphur spring, near Uspallata, Mendoza Province, Argentina, South America

Geothermal area with sulphur deposits and acidic brines, Dallol, Danakil depression, Ethiopia, Africa

Geothermal area with sulphur deposits and acidic brines, Dallol, Danakil depression, Ethiopia, Africa

Boardwalk through the solfatara field Bumpass Hell, Lassen Volcanic National Park, California, USA, North America

Hidden bay on the Mediterranean at sunrise. Look at the small beach of sand and pebbles, the beach is bathed in warm colours of the dawn in the morning. View of the sea at Xigia Sulfur Beaches, Zakynthos, Ionian Islands, Greece, Europe

Aerial view, volcanic crater with colourful sulphur deposits, near Frioland ao Fjallabaki, Iceland, Europe

The basin of hot sulphur spring in Bagno Vignoni and Hotel Le Terme at night, Orcia Valley, Tuscany, Italy, Europe

Two tourists standing beside steaming fumarole, solfatara in Hverarond, also Hverir or Namaskard, geothermal area, North Iceland, Iceland, Europe

Sulphuric vapours from a crack in the earth, Vulcano, Aeolian Islands, Italy, Europe

Sulphure formations, Dallol, Danakil Depression, Ethiopia, Africa

Sulphure formations, Dallol, Danakil Depression, Ethiopia, Africa

Hot volcanic springs, thermal bath, Saturnia, Tuscany, Italy, Europe

Sulfur vapor, petrified trees in New Blue Spring Road, limestone sinter terraces, steaming geysers, hot springs, Mammoth Hot Springs Terraces in Yellowstone National Park, Wyoming, United States of America

Sulfur spring, Salar de Uyuni salt lake, Uyuni, Bolivia, South America

Sulfur spring, Salar de Uyuni salt lake, Uyuni, Bolivia, South America