U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)

A woman is tattooed by an artist during Warsaw Tattoo Convention 2014 in Warsaw November 29, 2014. (Photo by Kacper Pempel/Reuters)

The Villarrica Volcano is seen at night from Pucon town, Chile, July 12, 2015. Villarrica, located near the popular tourist resort of Pucon, is among the most active volcanoes in South America. (Photo by Cristobal Saavedra/Reuters)

Buyan, a male Siberian brown bear, is given a shower by a zoo employee in his enclosure at the Royev Ruchey zoo in Russia's Siberian city of Krasnoyarsk June 24, 2014. The Siberian city has been experiencing temperatures of around 30 degrees Celsius over the last week. (Photo by Ilya Naymushin/Reuters)

A storm whips through a tented area occupied by Nepalese earthquake survivors as a mother grabs her infant child and runs to find shelter in Kathmandu, Nepal 23 May 2015. Nepalese, who lost their homes in earthquake and fear aftershocks, have been living in temporary shelter in open ground which they had to flee because of the heavy rain and powerful wind. (Photo by Narendra Shrestha/EPA)

A woman carries a stone cross in a cemetery in the village of Copaciu, southern Romania, on May 2, 2013. As part of a Holy Week tradition, Romanians visit, on Maundy Thursday, the graves of their loved ones, light fires and share food with community members in memory of the departed. Orthodox worshipers celebrate Easter on May 5. (Photo by Andreea Alexandru/ Mediafax)

Mount Sinabung volcano erupts, as seen from Tiga Pancur village, Karo Regency in Indonesia's North Sumatra province October 8, 2014. (Photo by Y. T. Haryono/Reuters)

A picture made available on 09 October 2016 shows competitors during a Legion Run event, in Sofiko near the city of Corinth, Greece, 08 October 2016. Legion Run is run covering five kilometres with obstacles of mud, fire, ice and barbed wire, which takes place in different countries around the globe. (Photo by Vassilis Psomas/EPA)