In the South Pacific, Vanatu reached a level four shortly before the eruption of Ambae's Manaro Voui volcano in early October, leaving many without safe water.

How volcanoes are made? 

When thick magma and large amounts of gas build up under the surface, eruptions can be explosive, expelling lava, rocks and ash into the air. Less gas and more viscous magma usually mean a less dramatic eruption, often causing streams of lava to ooze from the vent.

The mountain-like mounds that we associate with volcanoes are what remain after the material spewed during eruptions has collected and hardened around the vent. This can happen over a period of weeks or many millions of years.

 

0:00|2:08 rare FOOTAGE OF SOME of the world's worst natural dis a large eruption can be dangerous for people living near a volcano. Flows of searing lava, which can reach 2,000 degrees Fahrenheit (1,250 degrees Celsius) or more, can be released, burning everything in their path. Boulders of hardening lava can rain down on villages. Mud flows from rapidly melting snow can strip mountains and valleys bare and bury towns.Ash and toxic gases can cause lung damage and other problems, particularly for infants and the elderly. Scientists estimate that more than 260,000 people have died in the past 300 years from volcanic eruptions and their aftermath. Where are Earth's volcanoes?Volcanoes tend to exist along the edges between tectonic plates, massive rock slabs that make up Earth's surface. About 90 percent of all volcanoes exist within the Ring of Fire along the edges of the Pacific Ocean.Volcano

VIEW IMAGESTHREE VOLCANOESMount Semeru, seen with an ash plume, is the highest volcano on the Indonesian island of Java and has been in a constant eruption since 1967.  It lies at the southern end of the Tengger caldera, which contains smaller volcanoes Mount Bromo and Mount Batok (both seen in the foreground), and several others.PHOTOGRAPH BY JOHN STANMEYER, NATIONAL GEOGRAPHIC LAVA FLOWING INTO THE PACIFICWith a hiss of steam, lava flows into the Pacific Ocean in Hawaii Volcanoes National Park, Hawaii. Similar flows of molten rock have built up the Hawaiian islands over the course of more than 70 million years.PHOTOGRAPH BY STEPHEN ALVAREZ, NATIONAL GEOGRAPHICMOUNT ETNA, 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, NATIONAL GEOGRAPHICLIQUID LAVA ON MOUNT ETNAA few hundred degrees separates this pool of fiery orange magma in Italy’s Mount Etna from its hardened, gray crust. At nearly 11,000 feet (3,353 meters), Mount Etna is Europe’s highest active volcano.PHOTOGRAPH BY CARSTEN PETER, NATIONAL GEOGRAPHICVOLCANIC LIGHTNINGA bright bolt of lightning crackles within the ash cloud from the eruption of the Eyjafjallajökull volcano in Iceland in April 2010.  Volcanic lightning occurs when roiling ash particles rub against each other and become electrically charged.PHOTOGRAPH BY PETER VANCOILLIE, YOUR SHOTMOUNT ST. HELENS AFTER ERUPTIONA wisp of smoke escapes from Mount St. Helens’ dramatic eggshell-shaped crater after an eruption. Washington State’s volcano is most famous for its catastrophic 1980 eruption that killed 57 people, destroyed homes, bridges, and highways, and triggered an enormous debris avalanche that carved a mile-wide (1.6-kilometer-wide) crater on the mountain.PHOTOGRAPH BY STEVEN L. RAYMER, NATIONAL GEOGRAPHICERTALE VOLCANO CRATER, ETHIOPIAClimbers mount whorls of lava on the caldera of Ethiopia’s Ertale Volcano as steam escapes from a lava lake in the volcano’s crater, which can reach temperatures of 1,868°F (1,020°C).PHOTOGRAPH BY CARSTEN PETER, NATIONAL GEOGRAPHICBOILING MUD, ETHIOPIAA pool of mud boils near Dallol Volcano, in Ethiopia’s remote Danakil Depression. Volcanic explosion craters such as Dallol form during phreatic eruptions—where rising magma comes into contact with water beneath the surface of the Earth, causing a steam explosion.PHOTOGRAPH BY CARSTEN PETER, NATIONAL GEOGRAPHICCLEVELAND VOLCANO, ALASKACleveland Volcano releases a plume of ash that rises almost 20,000 feet (6,000 meters) above the North Pacific Ocean in this aerial photograph. Cleveland Volcano, located in the Aleutian Islands southwest of Alaska, failed to produce an eruption and the plume of ash detached from the volcano two hours after it formed.PHOTOGRAPH COURTESY NASA EARTH OBSERVATORYPAHOEHOE LAVA, Hawaiian lava flows on Kilauea volcano in Hawaii Volcanoes National Park. Unlike aa (pronounced “ah ah”) lava, flows relatively slowly, allowing an insulating skin to form that keeps the temperature close to 2,190°F (about 1,200°C). A 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 STEVE AND DONNA O'HARA, VOLCANO WATCH INTERNATIONAL/NATIONAL GEOGRAPHICAL stream of neon-orange lava cascades down, in Tanzania’s Great Rift Valley. "Mountain of God" in the language of the Masai, is the only volcano in the world eruption, an extremely fluid lava that contains almost no silicon.PHOTOGRAPH BY CARS TEN PETER, NATIONAL GEOGRAPHIC FERN GROWING FROM LAVA, HAWAII whisk fern grows from recently cooled lava in Hawaii Volcanoes National Park, Hawaii. Plants can return rapidly to areas affected by volcanic eruptions. Over time, lava and ash break down to form fertile soils ideal for agriculture.PHOTOGRAPH BY f LASTING, NATIONAL GEOGRAPHIC TWO ERUPTIONS volcanic eruption and the eruption of light from charged particles in the atmosphere—called the Northern Lights—occur at the same time in Iceland. The island nation was created by volcanic activity and today has 35 active volcanoes, which provide the country with plentiful geothermal power.PHOTOGRAPH BY JAMES APPLETON, YOUR SHOTASH CLOUDGeese fly past the ash cloud from the eruption of the Eyjafjallajökull volcano that began in April 2010. Ash from the volcano disrupted air traffic in Europe for more than a month.PHOTOGRAPH BY SNORRI GUNNARSSON, MY SHOTSTARS OVER MOUNT DAMAVANDStars whirl in the sky in a long-exposure photo of Mount Damavand in Iran. The mountain, which is part of the Elburz mountain range south of the Caspian Sea, is the highest volcano in Asia and the highest peak in the Middle East.PHOTOGRAPH BY SIAMAK SABET, YOUR SHOTLAKE LAACHGas bubbles up from the bottom of Laacher See (or Lake Laach) in Germany. A violent prehistoric eruption caused the Earth's crust to collapse and form a crater that filled with water. The lake lies in an area of Western Germany called the Eifel volcanic field.PHOTOGRAPH BY HANNAH BAUMERT, MY SHOTARENAL VOLCANOThe Arenal Volcano in Costa Rica erupts suddenly in February 2010, turning the sky an ominous yellow-brown. The volcano is one of the most active in the world. Lights illuminate the Lava Tube in the Hawaii Volcanoes National Park. Lava tubes serve as underground pipelines, allowing molten rock to flow under and away from volcanoes.PHOTOGRAPH BY KEVIN HAZEL-TON, MY SHOT LAVA FALLSLava flows into a valley in southern Iceland near the Eyjafjallajökull. About 1,900 volcanoes on Earth are considered active, meaning they show some level of activity and are likely to explode again. Many other volcanoes are dormant, showing no current signs of exploding but likely to become active at some point in the future. Others are considered extinct.