Volcanoes

Photograph by Chris Johns

The Pacific smolders as lava from Hawaii's Kilauea Volcano hits the ocean. Kilauea is a shield volcano, or a low, gently sloping volcano built almost entirely from basaltic lava flows. It is one of five such volcanoes that make up Hawaii's Big Island.

Photograph by Carsten Peter

Perched above the lighted city of Catania, Italy, Mount Etna hurls a fountain of fire skyward as rivers of lava spill down its flanks. In spite of its dazzling displays, Mount Etna is a relatively safe volcano with rare, compact eruptions and slow-flowing lava that gives people a chance to escape.

Photograph by Carsten Peter

A stream of neon-orange lava cascades down Ol Doinyo Lengai, in Tanzania’s Great Rift Valley. Ol Doinyo Lengai, "Mountain of God" in the language of the Maasai, is the only volcano in the world erupting natrocarbonatite lava, an extremely fluid lava that contains almost no silicon.

Photograph by Carsten Peter

Climbers mount whorls of lava on the caldera of Ethiopia’s Ertale Volcano as steam escapes from a lava lake in the volcano’s crater that can reach temperatures of 1,868°F (1,020°C).

Photograph by Peter Essick

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.

Photograph by Stephen Alvarez

With a hiss of steam, lava flows into the Pacific Ocean in Hawaii Volcanoes National Park, Hawaii. The Hawaiian island chain has been built up by similar flows of molten rock over millions of years.

Photograph by Richard du Toit/Minden Pictures

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.

Photograph by Steve and Donna O'Meara

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.

Photograph by Chris Waythomas/Alaska Volcano Observatory/ U.S. Geological Survey

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.

Photograph by John Stanmeyer

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.

From an email received December 2008