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National Aeronautics and Space Administration THE STAR WITNESS A P U B L I C A T I O N O F N A S A’S “A M A Z I N G S P A C E” E D U C A T I O N P R O G R A M Special Feature Volcanoes: Powerful Forces of Nature By NASA’s Amazing Space reporters August 2016 O N JUNE 15, 1991, a slumbering giant awakened. Mount Pinatubo, a volcano on the Philippines island of Luzon, erupted after lying dormant for 500 years. The mammoth eruption was the second largest volcanic outburst of the twentieth century. A series of huge explosions darkened the skies that day and created a column of ash that rose 21 miles (34 kilometers) in the atmosphere. On the way down, the ash mixed with rain from a typhoon and fell across 2,500 square miles (6,475 square kilometers). Although hundreds of people died, thousands of islanders living near the volcano were evacuated. Mount Pinatubo is just one of about 600 volcanoes throughout the world that have had known eruptions during recorded history. About 50 to 70 volcanoes erupt each year, making these giant powerhouses one of the most destructive forces on Earth. Not IMAGE: U.S. Geological Survey The eruption of the Mount Pinatubo volcano in the Philippines unleashed a giant plume of material hundreds of miles across. The volcanic outburst on June 15, 1991, was the second largest in the 20th century. all of them reside in tropical climates such as the Philippines. The largest volcanic outburst of the twentieth century occurred in Alaska, near the Arctic Circle. The powerful blast from Novarupta sent 3 cubic miles (12.5 cubic kilometers) of hot, liquefied rock and ash into the air. Falling ash measured more than a foot (0.3 meters) deep in a 3,000-squaremile (7,770-square-kilometer) area, roughly the size of Delaware. Continued, page 2… www.nasa.gov Continued from page 1… The blast felt around the world Volcanic eruptions have consequences beyond the regions around them. They can also affect the entire planet. The Mount Pinatubo blast sent millions of tons of pollutants into the air. Air currents spread the particles around the world, causing average global temperatures to drop by roughly 1 degree Fahrenheit (0.56 degrees Celsius) for about three years. The dip in temperature was caused by the layers of volcanic particles in the atmosphere, which blocked sunlight and cooled the planet. Sulfur dioxide from the eruption also enlarged the hole in Earth’s ozone layer in the Antarctic. Some volcanic eruptions have caused crops to fail, creating famines. Volcanic blasts also can disrupt air travel. The outburst from Iceland’s Eyjafjalkjokull volcano in 2010 grounded airplanes for several days as ash from the eruption swept across Europe. The volcano sits directly under the jet stream, which carried the ash into European airspace. The air travel disruption was the largest since the Second World War. Io: The volcano capital of the solar system These violent outbursts are not just confined to Earth. Scientists have observed volcanic eruptions on Jupiter’s moon Io. Imagine living on a world roughly the size of Earth’s moon where volcanic eruptions are almost a daily part of life. Welcome to Io, the volcano capital of the solar system. More active volcanoes reside on Io 2 Devastation after Pinatubo This town in the Philippines was badly damaged by a combination of the volcanic eruption of Mount Pinatubo and flooding from Typhoon Yunya. Heavy rainfalls, coupled with falling ash, caused large mudflows, which destroyed many bridges and made travel dangerous. IMAGE: U.S. Geological Survey Global effects of Mount Pinatubo eruption IMAGE: NASA/Goddard Space Flight Center Scientific Visualization Studio The map above represents the global distribution of sulfur dioxide and dust particles from the Mount Pinatubo eruption. A computer model tracked particles from the blast and found that it took less than three months to spread throughout Earth’s atmosphere. The colors in the graphic represent the atmospheric height of the particles. The blue dots are particles closer to Earth’s surface, while the red dots represent the highest particles in the atmosphere. than on any other world in the solar system. Io’s surface is pockmarked with active volcanic craters called calderas. These hot craters thrive in a world where the average surface temperature is a frigid minus 202 degrees Fahrenheit (minus 130 degrees Celsius). The heat near the volcanoes, however, can reach 3,000 degrees Fahrenheit (1,649 degrees Celsius), hot enough to keep liquid lava flowing. But once hot sulfur dioxide ash from volcanic blasts hits the moon’s surface, it turns to snow. The Voyager 1 spacecraft was the first observatory to discover active volcanoes on the volatile moon in 1979. Since then, astronomers have been using satellites, including NASA’s Galileo spacecraft and Hubble Space Telescope, and groundContinued, page 3… The 2010 eruption of Icelandic volcano, Eyjafjalkjokull ICELAND Eyjafjalkjokull Atlantic Ocean Plume from eruption IMAGE: David Karnå Eruption in progress: This view, taken from Þórolfsfell mountain, shows the dramatic fireworks of lava and ash produced by the eruption of the Eyjafjalkjokull volcano in Iceland, on May 10, 2010. Continued from page 2… based observatories to monitor Io’s turbulent, chaotic activity. The satellites spotted about 150 active volcanoes on Io. Astronomers, however, think the moon may have as many as 400 active volcanoes. IMAGE: Jeff Schmaltz, MODIS Rapid Response Team Plume from Eyjafjalkjokull eruption: This image, taken by NASA’s Aqua satellite, was made only days after the eruption of Iceland’s Eyjafjalkjokull volcano. Ash and a plume of material from the blast are sweeping across the Atlantic Ocean and moving into Europe. The wave of volcanic material impacted air travel in Iceland for more than a month and in Europe for several days. Voyager finds active volcanoes on Jupiter’s moon, Io Astronomers hit the jackpot In 2013 astronomers struck a gold mine when they witnessed three volcanoes on Io blasting material into space during a two-week period. Astronomers observed two of them on the same day in Io’s southern hemisphere. Using the W. M. Keck Observatory in Hawaii, astronomers calculated that the brightest outburst produced a lava flow that was 30 feet (9 meters) thick and spanned 50 square miles (130 square kilometers) — enough to LOKI PATERA Lava Caldera Lava lake This image of Jupiter’s moon Io from the Voyager 1 satellite shows several lava flows and calderas on Jupiter’s moon Io. Calderas are the centers of volcanic activity. The large black region below the center of the image is the active lava lake in Loki Patera, the largest volcanic depression on Io. IMAGE: NASA/JPL/USGS Continued, page 4… 3 Continued from page 3… cover Manhattan Island, the heart of New York City. The other eruption produced flows covering 120 square miles (311 square kilometers). Both eruptions generated what looked like “curtains of fire” as lava blasted from long gashes in Io’s crust. However, the third eruption two weeks later from yet another volcano was the most dramatic. The event, captured by the Gemini North telescope and NASA’s Infrared Telescope Facility, both in Hawaii, was brighter than the previous two eruptions and hotter than any volcanic eruption seen today on Earth. Astronomers compared the outburst to the destructive eruptions on our planet when it was young. A violent past In fact, the rocky planets — those planets closest to the sun — and many moons in our solar system show evidence of past volcanic activity. Mercury contains ash deposits. Mars is home to many extinct volcanoes, including Olympus Mons, the largest volcano in our solar system. These features formed millions of years ago when our solar system was much younger and its objects were much hotter. Many recipes for volcanic eruptions Although volcanoes are plentiful in the solar system, the forces that produce them vary. On Earth, the continents that make up our planet are part of massive “tectonic plates” located beneath our planet’s surface. These plates are always in motion, and volcanoes typically form where they collide or spread apart. Volcanoes can also Continued, page 5… Observations of volcanic activity on Jupiter’s volatile moon, Io Two plumes of material rising from separate volcanic eruptions appear in this image of Io, taken by the Galileo Orbiter. The first plume from the erupting caldera, Pillan Patera, appears to have a blue color, as it extends off the left edge of the moon. The second plume, from the Prometheus caldera, is colored red and is near the center of the image. The Prometheus caldera is marked by bright and dark rings. Two other volcanoes, Surya Patera and Culann Patera, are also shown. From the Galileo Orbiter From the Gemini North Telescope, Hawaii Surya Patera Prometheus Reddish plume Culann Patera Plume from erupting Pillan Patera IMAGE: NSF/NASA/JPL-Caltech/ UC Berkeley/Gemini Observatory Simultaneous eruptions: This image, taken in near-infrared light by the Gemini North Telescope, reveals two of the three volcanic outbursts that astronomers witnessed during a two-week period on Io. The largest and brightest blast appears at upper right; the fainter outburst can be seen at the bottom edge of the moon. A lava lake named Loki is the bright spot in the middle of Io. The outburst at upper right represented one of the largest observed eruptions on Io, the most volcanically active body in the solar system. From the Hubble Space Telescope IMAGE: NASA/JPL/University of Arizona Pele volcano erupting: In 1996, the Hubble Space Telescope observed a large plume of material erupting from Pele, one of Io’s most powerful volcanoes. The plume is the wispy, red material extending from the moon’s lower left edge. IMAGE: John Spencer (Lowell Observatory) and NASA 4 Continued from page 4… occur at a “hot spot” in the middle of a plate. Volcanoes form when liquid rock, called magma, from within the Earth travels up to the surface. At the surface, the liquid rock erupts to form lava flows and ash deposits. The volcano continues to grow, getting bigger over time, as it continues to erupt. Mercury’s varied surface Io: The big squeeze On Io, the volcanic activity is driven by Jupiter’s powerful tidal forces of gravity, which squeeze the moon’s interior and heat it up. Like Earth’s volcanoes, molten rock is then forced through Io’s surface, erupting as volcanoes. In fact, Io is the only place in the solar system, other than Earth, where active volcanoes have been observed ejecting extremely hot lava. Io, however, has a lower surface gravity than Earth. So material can leave Io’s surface more easily and travel far into space. For that reason, many Io eruptions can blast debris high above the moon. One such eruption shot plumes of material more than 300 miles (483 kilometers) high, forming a huge umbrella of hot material. Mars: Land of the giant volcanoes The volcanoes on Mars were active long ago and are now extinct. These dead volcanoes, however, are much larger than any volcano on Earth. For example, Mars’ Olympus Mons, the largest volcano in the solar system, is up to 100 times larger than Mauna Loa, Earth’s biggest active volcano. In fact, the entire chain of Hawaiian Islands (from Kauai to Hawaii) would fit inside Olympus Mons. IMAGE: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington This colorful view of Mercury, created with data taken by NASA’s Messenger spacecraft, is not the gray appearance that the planet presents to the human eye. Astronomers assigned the colors to show the chemical, mineralogical, and physical differences between the rocks that make up Mercury’s surface. One reason for the Martian volcanoes’ monstrous size is that Mars does not have tectonic plates beneath its surface that move the way they do on Earth. On our planet, as a plate drifts over a hot spot of magma, a new volcano forms. As the plate moves away, the volcano is separated from the magma, stops growing, and becomes extinct. The hot magma, however, finds another place in the surface to break through, and another volcano is formed. This process continues, creating a chain of volcanoes, like those that formed the Hawaiian Islands. Instead of building one large volcano, the erupting lava forms many smaller volcanoes. The surface on Mars, however, remains stationary over a hot spot of magma, and the erupting lava piles up in one place, making one giant volcano. Olympus Mons spans 374 miles (602 kilometers) across at its base and reaches an elevation of 16 miles (26 kilometers), more than twice as tall as Mauna Kea, a dormant volcano in Hawaii that is Earth’s tallest mountain as measured from its base, deep in the Pacific Ocean, to its peak. Like Io, Mars also has a lower surface gravity than Earth, which helped Continued, page 6… 5 Continued from page 5… to produce tremendous eruptions long ago. The lava flows on Mars also lasted longer — many weeks — and were more widespread, than those on our planet. Observations have captured a vast lava flow the size of the state of Oregon on Mars’ surface. In fact, volcanic features cover most of the planet’s surface. The Martian volcanoes are extinct because the planet’s core has cooled. The volcanoes, therefore, have no heat to power them. Olympus Mons, our solar system’s largest volcano This Hubble Space Telescope image of Mars shows the largest volcano in the solar system, Olympus Mons. The giant extinct volcano is the irregular circular feature just above the center of the image. Olympus Mons is 374 miles (602 kilometers) wide, as large as Arizona. Its summit is about 16 miles (26 kilometers) above the surrounding plains. It is three times higher than Mt. Everest (see close-up, below). Olympus Mons Shaping our solar system Volcanic activity has helped shape the landscape of Io and our other solar system neighbors. Spacecraft that have flown by Io since 1979 have observed numerous surface changes as a result of Io’s volcanic activity. Material launched by eruptions create large lava flows and paint the surrounding surface of Io in shades of yellow, red, white, black, and green. The volcanic material also is found in Io’s patchy atmosphere. The smooth plains are dotted with tall mountains, some rising higher than Mount Everest in Nepal, one of the tallest mountains on Earth. Unlike other solar system worlds, Io does not have any craters from asteroid impacts. Scientists think that new impact craters are buried by the frequent flow of volcanic material. Keeping watch IMAGE: NASA, J. Bell (Cornell U.) and M. Wolff (SSI) Close-up of Olympus Mons Side view Olympus Mons Mt. Everest Viking Orbiter 1’s view of Olympus Mons Outline of Arizona, to scale Olympus Mons Volcanoes are a tremendous force of nature, but thanks to ground-based observatories, space telescopes, and Earth-observing satellites, scientists have a better understanding of the impact of volcanoes on Earth and on our solar system neighbors. Continued, page 7… 6 IMAGE: NASA/JPL-Caltech This image of Olympus Mons was taken in 1978 from the Viking 1 Orbiter satellite. Continued from page 6… Scientists use satellite observations to keep vigil on volcanoes all over our world. With their perspective from space, satellites have a unique view of changes to Earth’s surface and atmosphere. Their heat-sensitive detectors, for example, reveal when and where lava appears, and help scientists predict where the lava will flow — alerting people to evacuate when a volcano awakens near towns and cities. Using satellites to track the ash spewed by Iceland’s Eyjafjalkjokull volcano in 2010, scientists mapped the location of the ash in the sky, keeping planes and passengers out of harm’s way. Satellite data also have helped researchers develop new techniques for monitoring eruptions. Scientists, One month after the Pinatubo eruption IMAGE: U.S. Geological Survey, July 1, 1991, by Willie Scott Devastation: This desolate wasteland resembles a prehistoric landscape. The image was taken of an area around the Mount Pinatubo volcano about one month after the devastating eruption in 1991. A mixture of hot gas, rock, and ash from the volcanic blast blankets the landscape, covering and charring vegetation. The environmental impacts of this natural disaster lasted for many years. Continued, page 8… Twenty-five years after Pinatubo eruption Renewal: This view of Lake Pinatubo in the Philippines may look like paradise, but 25 years ago this area was far from serene. Back then Lake Pinatubo was actually a crater where hot lava erupted from under the surface, exploding as a volcano. The devastating eruption of Mount Pinatubo was the second largest in the 20th century. Since the 1991 blast, the mountain and surrounding area have slowly sprung back to life. Many tourists visit the area, enjoying the flourishing green mountains and lake. IMAGE: Chris Tomnong 7 Continued from page 7… for example, used instruments and techniques developed by studying the eruptions of Mount St. Helens in Washington and other volcanoes in the 1980s to accurately predict the Mount Pinatubo outburst. By forecasting the impending eruption, scientists warned people living in the volcano’s shadow to move to safety, which saved thousands of lives. Although our solar system neighbors are far away, astronomers are using space-based and ground-based observatories to monitor geologic activity produced by active volcanoes on these nearby worlds. From death to life The saying “time heals all wounds” is certainly true regarding the destructive power of volcanic eruptions on Earth. Falling ash, flowing lava, mudslides, and deadly gases create a wasteland around the erupting volcano, wiping out towns, tearing apart highways, and killing wildlife and vegetation. In time, however, life begins to take hold again. Mount Pinatubo, for example, is green again 25 years after the huge eruption, and its volcanic crater has become a lake. More than 3,000 tourists a year climb the volcano and enjoy the beautiful view or swim in the lake. In Hawaii, coffee plantations thrive in the rich soil produced by lava flows from Mauna Loa, the world’s largest active volcano. SEE MORE Hubble images and read more Star Witness news stories at Amazing Space, NASA’s award-winning educational website for K–12 students and teachers. http://amazingspace.org/news www.nasa.gov