volcano
The Grand Prismatic hot spring in Yellowstone National Park is among the park's myriad hydrothermal features created by the fact that Yellowstone is a supervolcano. Robert B. Smith/AP hide caption
The eruption of Mount Pinatubo in the Philippines in 1991 spewed almost 20 million tons of sulfur dioxide into the atmosphere, causing worldwide temperatures to drop half a degree on average. Arlan Naeg/AFP/Getty Images hide caption
Mount Etna erupted on March 28, 1983. Lava flows destroyed homes and tourist destinations causing millions of dollars' worth of damage. Teams scrambled to divert the massive flow. Courtesy of John Lockwood hide caption
Lava near the leading edge of the flow oozes over a concrete slab and toward a tangerine tree before solidifying near the town of Pahoa on the Big Island of Hawaii earlier this week. U.S. Geological Survey/AP hide caption
A geologist maps the margin of the lava flow in the open field below Cemetery Road near the town of Pahoa on the Big Island of Hawaii. Dozens of residents from the village may be forced to evacuate. AP hide caption
A lava flow advances across the pasture between the Pahoa cemetery and Apaa Street, engulfing a barbed wire fence, near the town of Pahoa on the Big Island of Hawaii on Sunday. U.S. Geological Survey/AP hide caption
Japan Self-Defense Force (JSDF) soldiers and firefighters conduct rescue operations near the peak of Mount Ontake on Wednesday. KYODO/Reuters/Landov hide caption
Security personnel guard the entrance of a road leading to a trail on Mount Ontake in Nagano prefecture Tuesday, three days after the volcano erupted in central Japan. Jiji Press/AFP/Getty Images hide caption
A photo taken from a Kyodo News helicopter shows Japan's Self-Defense Forces personnel rescuing climbers who were in critical condition near the top of Mt. Ontake Monday, before rescue operations were suspended. Kyodo /Landov hide caption
A hiker is lifted by a rescue helicopter at Mt. Ontake, which erupted Saturday. The volcano straddles the Nagano and Gifu prefectures in central Japan. Kyodo/Reuters /Landov hide caption
A hiker's dramatic video captured the scene as a huge cloud of ash poured down the side of Mt. Ontake in Japan Saturday. YouTube hide caption
Harry Parr of Bompas and Parr gets volcanic on 10-ounce rib-eye steaks and ears of corn. Courtesy of Bompas and Parr hide caption
The Samalas volcanic crater at Rinjani National Park on Lombok Island, Indonesia. Rinjani National Park, Indonesia hide caption
Shinichi Kuramoto of the Center for Deep Earth Exploration in Japan displays a replica of earthquake fault rock. TOSHIFUMI KITAMURA/AFP/Getty Images hide caption