View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)

The Villarica volcano erupts near Pucon, Chile, early Tuesday, March 3, 2015. The Villarica volcano erupted Tuesday around 3 a.m. local time (06:00 GMT), according to the National Emergency Office, which issued a red alert and ordered evacuations. (Photo by Aton Chile/AP Photo)

Jo-Anne McArthur’s book of photographs puts the spotlight on ethics of zoos around the world. Accompanied by essays by Born Free Foundation’s Virginia McKenna and philosopher Lori Gruen, the images and stories are also shared online through “A Year of Captivity”. Here: Asian Elephant, Denmark, 2016. (Photo by Jo-Anne McArthur/Born Free Foundation/The Guardian)

National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

French actress Frederique Bel arrives for the NRJ Music Awards ceremony at the Festival Palace in Cannes December 13, 2014. (Photo by Eric Gaillard/Reuters)

The “Escape Velocity” moving sculpture by artist group Poetic Kinetics looms over Coachella festivalgoers on the Empire Polo Field, on the first day of the 2014 Coachella Music and Arts Festival in Indio, California, on April 11, 2014. (Photo by Chris Pizzello/Invision)

Culinary Specialist 2nd Class Jaqueline Rodriguez subdues a simulated suspect after being sprayed with oleoresin capsicum (OC) spray during security training aboard the amphibious dock landing ship USS Comstock (LSD 45). (U.S. Navy photo by Mass Communication Specialist 2nd Class Joseph M. Buliavac/Released). May 10, 2011

An artist shows her hands after working on a wall as part of a campaign to call for coexistence and the renouncement of violence through the painting of walls in Sanaa, Yemen March 15, 2015. (Photo by Mohamed al-Sayaghi/Reuters)