Jack Dykinga / Scalding hot water continuously spouting behind layers of mineral deposits, Fly Geyser, Black Rock Desert, Great Basin Desert, Nevada, USA

Milan Radisics / Aerial shot of steam geysers at Gunnhuver Hot Springs, Reykjanes Peninsula, Iceland, August 2018.

Milan Radisics / Aerial shot of steam geysers at Gunnhuver Hot Springs, Reykjanes Peninsula, Iceland, August 2018.

Igor Shpilenok / Kamchatka Brown Bear (Ursus arctos beringianus) by malachite (copper mineral) outcrop. Kronotsky Zapovednik Nature Reserve, Kamchatka Peninsula, Russian Far East, Valley of the Geysers, October.

Jeff Vanuga / Aerial view of Grand Prismatic Springs Midway Geyser Basin. Yellowstone National Park, Wyoming, July 2011.

Floris van Breugel / A skier glides past an erupting geyser in the Old Faithful geyser basin in Yellowstone National Park. The cold temperatures in the winter cause the geysers to release more steam than usual making the...

Jack Dykinga / Scalding hot water continuously spouting behind layers of mineral deposits, Fly Geyser, Black Rock Desert, Great Basin Desert, Nevada, USA

Sergey Gorshkov / Steam emitted from geysers, Geyser River, Valley of Geysers, Kamchatka, Russia

Sergey Gorshkov / Steam emitted from geysers, Geyser River, Valley of Geysers, Kamchatka, Russia

Sergey Gorshkov / Geyser River and geysers in background, Valley of Geysers, Kamchatka, Russia

Jeff Vanuga / Bull Bison (Bison bison) warming himself in the steam from the Firehole River, Upper Geyser Basin, Yellowstone National Park, Wyoming, USA, January

Jeff Vanuga / Lone Star Geyser erupting in Lone Star Geysyer Basin at night, Yellowstone National Park, Wyoming, USA, October 2007

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 6/11. July 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 2/11. July 2008

Igor Shpilenok / Velikan (or "Giant") Geyser, the largest geyser on Kamchatka, periodically shooting to a height of a nine-story building and releasing 30 tons of water per minute. Colonies of thermophilic bacteria co...

Igor Shpilenok / Kamchatka brown bear (Ursus arctos beringianus) at the "Stained glass window" in the Valley of the Geysers, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Kamchatka brown bear (Ursus arctos beringianus) at the Malachite Grotto, Valley of the Geysers, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Kamchatka brown bear (Ursus arctos beringianus) at the 'Stained glass window', Valley of the Geysers, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Kamchatka brown bear (Ursus arctos beringianus) enjoys hot steam from a geyser in Valley of the Geysers, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Kamchatka brown bear (Ursus arctos beringianus) near photographer's wooden cabin, Valley of the Geysers, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Steaming fissures and geysers in the caldera of Uzon Volcano, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Water flowing over rapids in the Geyser River, Kronotsky Zapovednik, Kamchatka, Far East Russia

Igor Shpilenok / Male Kamchatka Brown bear (Ursus arctos beringianus) marks trunk of Stone birch to denote territory during mating season, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / Kamchatka Brown bear (Ursus arctos beringianus) peering into Igor's cabin, Valley of the Geysers Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / Boiling red clay mud pots with steam, caused by underground volcanic activity, Valley of the Geysers, Kronotsky Zapovednik Reserve, Russia.

Igor Shpilenok / Kamchatka Brown bear (Ursus arctos beringianus) skirting a steaming thermal field, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / Female Kamchatka Brown bear (Ursus arctos beringianus) crossing stream, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / Kamchatka Brown bear (Ursus arctos beringianus) walking along the Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / The 'Fireplace' rock formation, Geyser River, Valley of the Geysers, Kronotsky Zapovednik Reserve, Russia.

Igor Shpilenok / Brown bear {Ursus arctos} mother with cubs, Valley of the Geysers, Kronotsky Zapovednik, Russia.

Igor Shpilenok / Kamchatka Brown bear (Ursus arctos beringianus) mother standing with cub, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / Stoat {Mustela erminea} running, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Igor Shpilenok / Kamchatka Brown bear (Ursus arctos beringianus) resting on warm ground next to thermal waters, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Pete Cairns / Line of Bison {Bison bison} geysers steaming, Yellowstone National Park, USA.

Pete Cairns / Morning glory pool, Old Faithful geyser, Yellowstone NP, Wyoming, USA

Pete Cairns / Landscape with Bison {Bison bison} and steam from geysers, Yellowstone NP, Wyoming, USA

Neil Lucas / Geyser known as Strokkur (the churn) blows once every 20-30 minutes. Iceland, Europe

Milan Radisics / Aerial shot of steam geysers at Gunnhuver Hot Springs, Reykjanes Peninsula, Iceland, August 2018.

Milan Radisics / Aerial shot of steam geysers at Gunnhuver Hot Springs, Reykjanes Peninsula, Iceland, August 2018.

Daniel Heuclin / Landscape with geysers and fumaroles, El Tatio geyser field, 4320m above sea level, Andes Mountains, northern Chile.

Daniel Heuclin / Landscape with geysers and fumaroles, El Tatio geyser field, 4320m above sea level, Andes Mountains, northern Chile.

Daniel Heuclin / Landscape with active geysers and fumaroles. El Tatio geyser field, 4320m above sea level, Andes Mountains, northern Chile.

Daniel Heuclin / Geysers and fumaroles, El Tatio geyser field, 4320m above sea level, Andes Mountains, northern Chile.

Daniel Heuclin / People gathered to watch the active geysers and fumaroles. El Tatio geyser field, 4320m above sea level, Andes Mountains, northern Chile.

Ingo Arndt / Old Faithful geyser errupting, Yellowstone National Park, Wyoming, USA

David Noton / Geysers at Hverarond, near Myvatn, north eastern Iceland, March 2016.

Kirkendall-Spring / Noris Geyser Basin, Yellowstone National Park, Wyoming, USA. September 2015.

Kirkendall-Spring / Black Pool inWest Thumb Geyser Basin, Yellowstone National Park, Wyoming, USA. September 2015.

Jeff Vanuga / American buffalo (Bison bison) grazing on Fountain Flat with geysers erupting behind. Yellowstone National Park, Wyoming, USA, June.

Jeff Vanuga / Lily flower shaped Fleur de Lis Spring, in the Orion Group of Geysers, Shoshone Geyser Basin, Yellowstone National Park, Wyoming, USA, August 2015.

Cyril Ruoso / Geysers and landscape at Hveravellir, Iceland, August 2003.

Ben Cranke / Panoramic of geysers, Yellowstone National Park, Wyoming, USA, January 2011.

Ben Cranke / Snow covered fir trees with tree tops killed by fumes from geysers, Yellowstone National Park, January 2011.

Jeff Vanuga / Lion Geyser on the Geyser Hill Group of Geysers. Upper Geyser Basin, Yellowstone National Park, Wyoming, USA, January 2013.

Peter Cairns / American Bison (Bison bison) standing in front of winter geysers, Yellowstone National Park, Wyoming, USA, February 2013..

Peter Cairns / Herd of Bison (Bison bison) in front of geysers in winter, Yellowstone National Park, Wyoming, USA, February 2013.

Peter Cairns / Procession of Bison (Bison bison) in front of geysers in winter, Yellowstone National Park, Wyoming, USA, February 2013.

Kirkendall-Spring / Crowd observing the Turban and Giant Geysers in the Upper Geyser Basin of Yellowstone National Park, Wyoming, USA, June 2013.

Denis-Huot / Lesser flamingo (Phoeniconaias minor) aerial view of flock and geysers, Bogoria Game Reserve, Kenya

Igor Shpilenok / Ranger station in the Valley of the Geysers in early Autumn. Kronotsky Zapovednik Nature Reserve, Kamchatka Peninsula, Russian Far East, October. Sequence 2 of 3.

Igor Shpilenok / Ranger station in the Valley of the Geysers in summer. Kronotsky Zapovednik Nature Reserve, Kamchatka Peninsula, Russian Far East, June 2006. Sequence 1 of 3.

Daniel Heuclin / Geysers, El Tatio, Atacama, Chile, September 2009

Gavin Hellier / People standing by Strokkur (the Churn) geyser which spouts up to 35 meters erupting every 10 minutes, Golden Circle, Iceland 2006

Gavin Hellier / Coloured pools created by algae and mineral deposits in geysir, Iceland, 2006

Christophe Courteau / Prince of Wales Feather geyser Whaka Rotorua North Is New Zealand

Mark Taylor / Hot spring and colourful algal mat at Yellowstone National Park, Wyoming, USA

Mark Taylor / Old Faithful geyser blowing, Yellowstone National Park, Wyoming, USA

Orsolya Haarberg / Hot spring in Hveravellir, Iceland.

Paul D Stewart / Long exposure (30 second) exposure of Clepsydra Geyser taken at night by moon light with stars visible in sky. This geyser is located in the Lower Geyser Basin of Yellowstone National Park in USA. The...

Jack Dykinga / Rivers of red algae across bacterial mats, at sunset, Grand Prismatic Geyser, Yellowstone National Park, Wyoming, USA

Erlend Haarberg / Northern lights and the Strokkur Geyser, Iceland, March 2011

Peter Cairns / Photographer lined up on boardwalk to photograph Castle Geyser at Old Faithful geothermal area, dawn, Yellowstone National Park, Wyoming, USA, September 2008

Peter Cairns / Photographers lined up on boardwalk to photograph Castle Geyser at Old Faithful geothermal area, dawn, Yellowstone National Park, Wyoming, USA, September 2008

Kirkendall-Spring / Winter landscape in the Geyser Hill area withOld Faithful erupting in the background, Yellowstone National Park, Wyoming, USA, February 2011

Kirkendall-Spring / Castle Geyser erupting in the Upper Geyser Basin of Yellowstone National Park, Wyoming, USA, February 2011

Igor Shpilenok / Igor Shpilenok photographing in Valley of the geysers, Kamchatka, Far East Russia, May 2007, photograph by Dmitry Shpilenok

Igor Shpilenok / Igor Shpilenok photographing Kamchatka brown bear (Ursus arctos beringianus) amongst geysers, Kamchatka, Far East Russia, photograph by Ivan Seredkin

Sergey Gorshkov / Kamchatka Brown bear (Ursus arctos beringianus) grazing on grass beside rocks and geothermal activity, Kamchatka, Far east Russia, January

Juan Carlos Munoz / Strokkur geyser errupting. The geyser is in the geothermic region beside the Hvítá River. Iceland, July 2009

Jack Dykinga / Tatio Geysers in early morning light, with steam rising from scalding hot water, coloured from mineral deposits. Atacama, Chile. April 2009

Sergey Gorshkov / Steam emitted from geysers, Geyser River, Valley of Geysers, Kamchatka, Russia

Sergey Gorshkov / Steam emitted from geysers, Geyser River, Valley of Geysers, Kamchatka, Russia

Sergey Gorshkov / Keyflower Orchid (Dactylorhiza aristata) flowers with geysers in background, Valley of Geysers, Kamchatka, Russia

Igor Shpilenok / Aerial view of Kamchatka landslide, where on 3 June 2007 a massive landslide buried part of Kamchatka's Valley of the Geysers. Kronotsky Zapovednik, Kamchatka, Russia.

Jeff Vanuga / Giant Geyser venting steam, Upper Geyser Basin, Yellowstone National Park, Wyoming, USA, January 2008

Jeff Vanuga / Steve Fuller photographing in the West Nymph Lake Creek Geyser area, Yellowstone National Park, Wyoming, USA, October 2008

Jeff Vanuga / Thermal hot springs along the Firehold River, Upper Geyser Basin, Yellowstone National Park, Wyoming, USA, October 2008

Jeff Vanuga / Thermal hot springs along the Firehold River, Upper Geyser Basin, Yellowstone National Park, Wyoming, USA, October 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 8/11. July 2008

Inaki Relanzon / The Strokkur about to erupt, the biggest geyser active in the Geysir area, SW Iceland. July 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 10/11. July 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 1/11. July 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland. Sequence 2/2. July 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 5/11. July 2008

Inaki Relanzon / Tourists watching eruption of The Strokkur, the biggest geyser active in the Geysir area, SW Iceland, sequence 3/11. July 2008