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Emissions from Anatahan
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Emissions from Anatahan |
| Description |
On March 17, 2007, the Anatahan Volcano, in the Northern Mariana Islands, released a plume of ash and/or steam. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] flying onboard the Aqua [ http://aqua.nasa.gov ] satellite captured this image on March 18, 2007, as the volcano's emissions continued. In this image, the volcanic plume pushes toward the southeast then changes direction slightly and aims for the islands of Saipan and Tinian. The volcanic plume is a little darker and more diffuse in shape than the nearby opaque white clouds. Volcanic emissions of sulfur dioxide sometimes react with water and sunlight to create vog—a haze that hangs over the region. Previous eruptions of Anatahan have created substantial vog. [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12832 ] Although the chemical composition of the plume cannot be identified from a single picture, south of Saipan and Tinian, the plume takes on an extra-hazy appearance consistent with volcanic fog. The same day MODIS acquired this image, the U.S. Air Force Weather Agency reported an odor of sulfur (which would also suggest the presence of vog) on Guam, approximately 200 kilometers southwest of Saipan.Anatahan [ http://www.volcano.si.edu/world/volcano.cfm?vnum=0804-20= ] is a stratovolcano composed of alternating layers of hardened lava, ash, and rock. Its first recorded eruption [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=15288 ] occurred in May 2003. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. The MODIS Rapid Response Team provides daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Anatahan ] of Anatahan. |
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Eruption of Anatahan
| Title |
Eruption of Anatahan |
| Description |
MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Anatahan ]., A week after its largest eruption in recorded history, the Anatahan volcano is still steaming. A plume of ash and steam rises from the volcano in this series of Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) images, acquired between April 7 and April 13, 2005, by NASA's Terra [ http://terra.nasa.gov/ ] and Aqua [ http://aqua.nasa.gov/ ] satellites. On April 6, the volcano erupted explosively, sending approximately 50 million cubic meters of ash up to 15,240 maters (50,000 feet) into the air. As of April 12, the ash plume had spread over 2,200 kilometers (1,200 nautical miles) west of the volcano to the Philippine Sea. The large eruption also impacted the ocean, as this series of images shows. Starting on April 7, the ocean to the north of the volcano had turned green. Two days later, the circular discoloration had expanded to a ring of green on the north and west sides of the volcano. By April 11, the ring of green water took on a brown shade and expanded even further. On April 13, the discolored water was dark brown, only faintly visible against the black ocean water. The band of discolored water forms a long oval that radiates away from the island to the north and the south, nearly reaching Saipan in the south. A second faint brown-green band of water rings Anatahan. There are several possible explanations for the discolored ocean water, says Frank Trusdell, a geologist with the U.S. Geological Survey at the Hawaiian Volcano Observatory. Trusdell has been monitoring Anatahan's eruption in collaboration with geologists from Saipan. First, ash may have settled in the water near the volcano. Light-colored ash floating near the surface of the ocean would reflect light, giving the water the green tint seen here. The ash would have thinned as it drifted away from the island, reflecting less and less light as it did so. This would account for the darkening color on later days. A second possible explanation is that phytoplankton are feasting on the iron-rich ash that has settled in the water. After Anatahan's first recorded eruption in May 2003, the ocean sprang to life around the volcano. The newly-fallen ash served as fertilizer for tiny ocean plants, called phytoplankton, that grow near the ocean's surface. Dense phytoplankton blooms give the ocean a green tint in satellite imagery. When the blooms die, they fade to brown and disappear as the plants sink into the ocean. There are other, far less plausible explanations for the discoloration seen in these images, says Trusdell, but it's impossible to pinpoint the cause without information from the ground. A week after the eruption, the area around the volcano remains sealed off as Anatahan continues to let off steam, reminding its observers that it's not finished yet. NASA images courtesy the MODIS Rapid Response Team at NASA GSFC. Daily images of the volcano are available from the |
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Eruption of Anatahan
| Title |
Eruption of Anatahan |
| Description |
MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Anatahan ]., A week after its largest eruption in recorded history, the Anatahan volcano is still steaming. A plume of ash and steam rises from the volcano in this series of Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) images, acquired between April 7 and April 13, 2005, by NASA's Terra [ http://terra.nasa.gov/ ] and Aqua [ http://aqua.nasa.gov/ ] satellites. On April 6, the volcano erupted explosively, sending approximately 50 million cubic meters of ash up to 15,240 maters (50,000 feet) into the air. As of April 12, the ash plume had spread over 2,200 kilometers (1,200 nautical miles) west of the volcano to the Philippine Sea. The large eruption also impacted the ocean, as this series of images shows. Starting on April 7, the ocean to the north of the volcano had turned green. Two days later, the circular discoloration had expanded to a ring of green on the north and west sides of the volcano. By April 11, the ring of green water took on a brown shade and expanded even further. On April 13, the discolored water was dark brown, only faintly visible against the black ocean water. The band of discolored water forms a long oval that radiates away from the island to the north and the south, nearly reaching Saipan in the south. A second faint brown-green band of water rings Anatahan. There are several possible explanations for the discolored ocean water, says Frank Trusdell, a geologist with the U.S. Geological Survey at the Hawaiian Volcano Observatory. Trusdell has been monitoring Anatahan's eruption in collaboration with geologists from Saipan. First, ash may have settled in the water near the volcano. Light-colored ash floating near the surface of the ocean would reflect light, giving the water the green tint seen here. The ash would have thinned as it drifted away from the island, reflecting less and less light as it did so. This would account for the darkening color on later days. A second possible explanation is that phytoplankton are feasting on the iron-rich ash that has settled in the water. After Anatahan's first recorded eruption in May 2003, the ocean sprang to life around the volcano. The newly-fallen ash served as fertilizer for tiny ocean plants, called phytoplankton, that grow near the ocean's surface. Dense phytoplankton blooms give the ocean a green tint in satellite imagery. When the blooms die, they fade to brown and disappear as the plants sink into the ocean. There are other, far less plausible explanations for the discoloration seen in these images, says Trusdell, but it's impossible to pinpoint the cause without information from the ground. A week after the eruption, the area around the volcano remains sealed off as Anatahan continues to let off steam, reminding its observers that it's not finished yet. NASA images courtesy the MODIS Rapid Response Team at NASA GSFC. Daily images of the volcano are available from the |
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Eruption of Anatahan
| Title |
Eruption of Anatahan |
| Description |
MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Anatahan ]., A week after its largest eruption in recorded history, the Anatahan volcano is still steaming. A plume of ash and steam rises from the volcano in this series of Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) images, acquired between April 7 and April 13, 2005, by NASA's Terra [ http://terra.nasa.gov/ ] and Aqua [ http://aqua.nasa.gov/ ] satellites. On April 6, the volcano erupted explosively, sending approximately 50 million cubic meters of ash up to 15,240 maters (50,000 feet) into the air. As of April 12, the ash plume had spread over 2,200 kilometers (1,200 nautical miles) west of the volcano to the Philippine Sea. The large eruption also impacted the ocean, as this series of images shows. Starting on April 7, the ocean to the north of the volcano had turned green. Two days later, the circular discoloration had expanded to a ring of green on the north and west sides of the volcano. By April 11, the ring of green water took on a brown shade and expanded even further. On April 13, the discolored water was dark brown, only faintly visible against the black ocean water. The band of discolored water forms a long oval that radiates away from the island to the north and the south, nearly reaching Saipan in the south. A second faint brown-green band of water rings Anatahan. There are several possible explanations for the discolored ocean water, says Frank Trusdell, a geologist with the U.S. Geological Survey at the Hawaiian Volcano Observatory. Trusdell has been monitoring Anatahan's eruption in collaboration with geologists from Saipan. First, ash may have settled in the water near the volcano. Light-colored ash floating near the surface of the ocean would reflect light, giving the water the green tint seen here. The ash would have thinned as it drifted away from the island, reflecting less and less light as it did so. This would account for the darkening color on later days. A second possible explanation is that phytoplankton are feasting on the iron-rich ash that has settled in the water. After Anatahan's first recorded eruption in May 2003, the ocean sprang to life around the volcano. The newly-fallen ash served as fertilizer for tiny ocean plants, called phytoplankton, that grow near the ocean's surface. Dense phytoplankton blooms give the ocean a green tint in satellite imagery. When the blooms die, they fade to brown and disappear as the plants sink into the ocean. There are other, far less plausible explanations for the discoloration seen in these images, says Trusdell, but it's impossible to pinpoint the cause without information from the ground. A week after the eruption, the area around the volcano remains sealed off as Anatahan continues to let off steam, reminding its observers that it's not finished yet. NASA images courtesy the MODIS Rapid Response Team at NASA GSFC. Daily images of the volcano are available from the |
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Eruption of Anatahan
| Title |
Eruption of Anatahan |
| Description |
MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Anatahan ]., A week after its largest eruption in recorded history, the Anatahan volcano is still steaming. A plume of ash and steam rises from the volcano in this series of Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) images, acquired between April 7 and April 13, 2005, by NASA's Terra [ http://terra.nasa.gov/ ] and Aqua [ http://aqua.nasa.gov/ ] satellites. On April 6, the volcano erupted explosively, sending approximately 50 million cubic meters of ash up to 15,240 maters (50,000 feet) into the air. As of April 12, the ash plume had spread over 2,200 kilometers (1,200 nautical miles) west of the volcano to the Philippine Sea. The large eruption also impacted the ocean, as this series of images shows. Starting on April 7, the ocean to the north of the volcano had turned green. Two days later, the circular discoloration had expanded to a ring of green on the north and west sides of the volcano. By April 11, the ring of green water took on a brown shade and expanded even further. On April 13, the discolored water was dark brown, only faintly visible against the black ocean water. The band of discolored water forms a long oval that radiates away from the island to the north and the south, nearly reaching Saipan in the south. A second faint brown-green band of water rings Anatahan. There are several possible explanations for the discolored ocean water, says Frank Trusdell, a geologist with the U.S. Geological Survey at the Hawaiian Volcano Observatory. Trusdell has been monitoring Anatahan's eruption in collaboration with geologists from Saipan. First, ash may have settled in the water near the volcano. Light-colored ash floating near the surface of the ocean would reflect light, giving the water the green tint seen here. The ash would have thinned as it drifted away from the island, reflecting less and less light as it did so. This would account for the darkening color on later days. A second possible explanation is that phytoplankton are feasting on the iron-rich ash that has settled in the water. After Anatahan's first recorded eruption in May 2003, the ocean sprang to life around the volcano. The newly-fallen ash served as fertilizer for tiny ocean plants, called phytoplankton, that grow near the ocean's surface. Dense phytoplankton blooms give the ocean a green tint in satellite imagery. When the blooms die, they fade to brown and disappear as the plants sink into the ocean. There are other, far less plausible explanations for the discoloration seen in these images, says Trusdell, but it's impossible to pinpoint the cause without information from the ground. A week after the eruption, the area around the volcano remains sealed off as Anatahan continues to let off steam, reminding its observers that it's not finished yet. NASA images courtesy the MODIS Rapid Response Team at NASA GSFC. Daily images of the volcano are available from the |
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Eruption of Anatahan
| Title |
Eruption of Anatahan |
| Description |
Ash rained down on Saipan, the main island in the chain of islands that make up the Northern Mariana Islands, and its neighbor Tinian on April 6, 2005. The sky over the islands darkened when the Anatahan volcano exploded late on April 5, and nearly 12 hours later, when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image, the islands were still completely obscured by a brown cloud of ash. No one was injured in the eruption, but residents have been warned to remain indoors and avoid drinking ash-contaminated water. The fourteen islands of the Northern Mariana Islands, including Anatahan, form a U.S. territory. Sitting 320 kilometers south of the volcano, Guam (a separately administered U.S. Territory) does not appear to have been affected by the ash. The Anatahan volcano itself is actually two volcanoes with overlapping summit calderas. The volcano forms the tiny island of Anatahan, which measures 9 kilometers long by 3 kilometers wide. The larger of the two peaks rises 788 meters from the surface of the sea, while the smaller peak is just 68 meters above sea level. The volcano's first recorded eruption was in May 2003. The April 5 eruption is the largest the volcano has produced since May 2003. NASA image courtesy Liam Gumley, University of Wisconsin-Madison, made from data provided by NOAA/NESDIS. |
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