Japan Self-Defense Force (JSDF) soldiers and firefighters make rescue works among mountain lodges, covered with volcanic ash near the peak of Mt. Ontake, which straddles Nagano and Gifu prefectures in this September 28, 2014 photo taken and released by Kyodo. More than 30 people were feared dead on Sunday near the peak of the Japanese volcano that erupted a day earlier, sending a huge cloud of ash and rock tumbling down its slopes, while packed with hikers. (Photo by Reuters/Kyodo News)

Yannis Behrakis, one of Reuters' most decorated and best-loved photographers, has passed away after a long battle with cancer. He was 58. Here: A pro-government Sierra Leonean fighter bites a bullet as he takes position in no man's land 2 km ahead of Rogberi junction where evidence of executed UN troops were found after heavy fighting between government troops and RUF rebels 100 km north east of Freetown, Sierra Leone, May 23, 2000. (Photo by Yannis Behrakis/Reuters)

An armed youth loyal to the Houthi movement takes part in a protest against the Saudi-backed exiled government deciding to cut off the Yemeni central bank from the outside world, in the capital Sanaa, Yemen August 25, 2016. (Photo by Mohamed al-Sayaghi/Reuters)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

A woman walks with her baby past a PM militarized police soldier in position and aiming his rifle in Rocinha favela in Rio de Janeiro, Brazil on September 23, 2017. Although shooting was reported in the early hours of Saturday in Rocinha – for the seventh day running – officials said that Friday's deployment of 950 soldiers to reinforce police had brought the crisis under control. (Photo by Carl De Souza/AFP Photo)

is a concentrated solar power plant with a molten salt heat storage system. It is located within the city limits of Fuentes de Andalucía in the province of Seville, Spain.

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)