Chill And Chill

Gas and steam rise from a volcanic vent in New Zealand. This small island nation uses the Earth's heat to generate about 12 percent of its energy demands.

Pavlof Volcano blasts clouds of ash and steam to a height of about 18,000 feet (5,490 meters) over the Alaska Peninsula during an August 2007 eruption. Pavlof is the most dangerous type of volcano—a stratovolcano— with the potential for highly explosive eruptions. Stratovolcanoes tend to form where one of the Earth's tectonic plates descends below another.

Pahoehoe lava flows on Kilauea Volcano in Hawaii Volcanoes National Park. Unlike aa (pronounced "ah ah") lava, pahoehoe flows relatively slowly, allowing an insulating skin to form that keeps the temperature close to 2,190 degrees Fahrenheit (about 1,200 degrees Celsius). Aa lava, on the other hand, moves faster and doesn't have time to develop a skin, resulting in a cooler flow with a more angular texture.

Navbiotum Volcano lies dormant on the southern shore of Lake Turkana in Kenya. Once known as Lake Rudolf, Lake Turkana is the northernmost lake in the Great Rift Valley, a highly volcanic region that runs 3,700 miles (6,000 kilometers) from Mozambique to Syria.

Green vegetation surrounds villages on the slopes of Mount Merapi, a highly active volcano in Central Java, Indonesia. Thousands of people, lured by fertile volcanic soils, live on or near Merapi. Many lives have been lost to the volcano's frequent eruptions, which are accompanied by high-speed pyroclastic flows and mudflows called lahars.