Hot lava trickles down from the Stromboli volcano on August 9, 2014 in Aeolian Islands, Italy. Lava flows down the Mount Stromboli off the Sicilian coast in southern Italy. The volcano – at 3,034ft – is one of the most active in Europe and has been erupting continuously since 1932. (Photo by Tom Pfeiffer/Barcroft Media)

Young Christian Lebanese women, who are members of Kataeb Phalangist party, show their skill in handling arms while they train in a village between Christian-controlled eastern port of Jounieh and the Christian village of Zahle in the west Lebanon on September 9, 1976. The Lebanese civil war erupted in April 1975. (Photo by Erich Stering/AFP Photo)

Participants dressed in Heroic Fantasy costumes pose for a picture as they wait backstage during the first edition of the HeroFestival in Marseille, November 9, 2014. The festival is dedicated to American superhero comics, Japanese mangas, Heroic Fantasy characters and video games universes. (Photo by Jean-Paul Pelissier/Reuters)

Mariam, a 9-year-old girl, carries her brother as she stands with other children at an underground ancient cemetery in Jabal al-Zawiya in the southern countryside of Idlib November 26, 2014. Residents are using ancient caves and cemeteries as underground shelters to hide in during shelling from forces loyal to President Bashar al-Assad. Picture taken November 26, 2014. (Photo by Khalil Ashawi/Reuters)

The bare feet of a devotee are pictured as she takes a dip at the Bagmati River during the “Bol Bom” (Say Shiva) pilgrimage in Kathmandu July 21, 2014. The faithful, chanting the name of Lord Shiva, run about 15 km (9 miles) barefooted toward Pashupatinath temple seeking good health, wealth and happiness. (Photo by Navesh Chitrakar/Reuters)

Participants dressed as Santa Claus gather shortly before the 4th annual Michendorf Santa Run (Michendorfer Nikolauslauf) on December 9, 2012 in Michendorf, Germany. Over 800 people took part in this year's races that included children's and adults' races. (Photo by Sean Gallup)

A visitor walks past the life-size sculpture “Security Guard” by Marc Sijan at The Armory Show, New York's annual international art fair, at Piers 92 and 94 on March 9, 2012 in New York City. The show features paintings, photographs, sculpture and other works of art by artists including Andy Warhol, Cindy Sherman and Pablo Picasso. (Photo by Mario Tama/Getty Images)

A sofa floats in the polluted waters of Jacarepagua Lagoon, during a press tour in Rio de Janeiro, March 9, 2015. A press tour was organised by biologist Mario Moscatelli, to call attention to pollution on the waters of the lagoons which surround the Rio 2016 Olympic Park. (Photo by Ricardo Moraes/Reuters)