An aerial view shows a sinkhole 3.5 km (2 miles) to the east of Solikamsk-2 mine in Perm region, November 20, 2014. Shares in Russia's Uralkali, the world's top potash producer, fell sharply for a second day on Wednesday after a mine accident that could reduce global supplies and push up prices of the crop nutrient worldwide. Uralkali shares have fallen 28 percent since Tuesday when it suspended work at its Solikamsk-2 mine, which accounts for a fifth of the company's output and 3.5 percent of global capacity, following an inflow of water. A sinkhole, stretching 30 by 40 metres (yards), found at an abandoned mine 3.5 km (2 miles) to the east, increased concern about the future of the mine because an inflow of water and the resulting sinkhole in 2006 forced another Uralkali operation to shut permanently. (Photo by Reuters/Press service of Uralkali company)

Revellers chase a bull into the sea during the “Bous a la Mar” festival on July 14, 2011 in Denia, Spain. The Spanish “Bous a la Mar” or “Bulls to the Sea” festival is held in honour of the Santisima Sangre and commemorate a monk named Pedro Esteve, who, as the legend has it, saved the coastal town of Denia from a plague in 1633. The bulls chased into the sea are later brought back to land by small boats. (Photo by Jasper Juinen/Getty Images)

These powerful images capture the spear-wielding tribes of Papua new Guinea who believe they are possessed with the spirit of the crocodile. They show how the Kangunaman clansmen scar their backs to resemble reptile scales while the Huli Wigmen wear elaborate headdresses to signal they are ready for battle. (Photo by Trevor Cole/Media Drum World)

A large Mantle or Desk Clock featuring a fossil ammonite at its center, carved from the South American wood Keolbra with radiating Walnut spines. The clock hangs on a round, Plexiglass back supported by a wood base (Bubinga). The clockworks is a quartz, high-torque movement that runs on a single AA battery.

Actress with the Donbass Opera Theatre prepares to perform Eugene Onegin in Donetsk, Ukraine, Saturday, February 7, 2015. For the few dozen spectators that turn up, the weekly performances at the city's opera house serve as a respite from the war raging outside between Russian-backed separatists and Ukrainian government forces. (Photo by Petr David Josek/AP Photo)

Caporal dancers perform during the carnival celebrations in Oruro, Bolivia, Saturday February 14, 2015. The Carnival of Oruro which is a religious festival dating back more than 2000 years in an ongoing pagan-catholic blend of religious practice in the region, and is one of UNESCO's Masterpieces of the Oral and Intangible Heritage of Humanity. (Photo by Juan Karita/AP Photo)

Pilgrims dressed in traditional Bavarian clothes attend the traditional Georgi horse riding procession on Easter Monday in heavy snowfall, in the southern Bavarian town of Traunstein April 6, 2015. Since the early 16th century, farmers have taken part in the pilgrimage to bless their horses. This tradition, the “Georgiritt”, goes back to the legend of Saint George, the horsemen's patron saint. (Photo by Michael Dalder/Reuters)