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Oahu, Hawaii ASTER
This 60 by 50 kilometer (37
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12/8/00
| Date |
12/8/00 |
| Description |
This 60 by 50 kilometer (37 by 31 mile) scene from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite shows almost the entire island of Oahu, Hawaii, on June 3, 2000. Oahu is the commercial center of Hawaii, and tourism is the largest contributor to the economy. Among the many popular beaches is the renowned Waikiki Beach, backed by the famous Diamond Head, an extinct volcano. The largest community, Honolulu, is the state capital. Built in Japan for the Ministry of International Trade and Industry, ASTER is one of several Earth-observing instruments on the Terra satellite, launched in December 1999. The Terra spacecraft, the flagship of a fleet of satellites dedicated to understanding our global environment, is part of NASA's Earth Sciences Enterprise, a long-term research program dedicated to understanding how human-induced and natural changes affect our world. More information about ASTER is available online at http://asterweb.jpl.nasa.gov . Image credit: NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team ##### |
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Home Reef Reborn
| title |
Home Reef Reborn |
| description |
In the South Pacific, south of Late Island along the Tofua volcanic arc in Tonga, the volcanic island Home Reef is being re-born. The island is thought to have emerged after a volcanic eruption in mid-August that also spewed large amounts of floating pumice into Tongan waters and swept across to Fiji about 350 km (220 miles) to the west of where the new island formed. In 2004, a similar eruption created an ephemeral island about 0.5 by 1.5 km (0.3 by 0.9 miles) in size, it was no longer visible in an ASTER image acquired November 2005. This simulated natural color image shows the vegetation-covered stratovolcanic island of Late Island in the upper right. Home Reef is found in the lower left. The two bluish plumes are hot seawater that is laden with volcanic ash and chemicals, the larger one can be traced for more than 14 km (8.4 miles) to the east. The image was acquired Oct. 10, 2006 and covers an area of 24.3 by 30.2 km. It is located at 18.9 degrees south latitude, 174.7 degrees west longitude. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitors the changing surface of our planet. It is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Image credit: NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team |
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Floods in Gonaives, Haiti
| Title |
Floods in Gonaives, Haiti |
| Description |
The floods that claimed the lives of at least 1,500 Haitians and left as many missing, also filled a large lake basin outside of Gonaives. The basin, which was a dry dust bowl on August 8, 2001, was still completely covered with water on October 3, 2004, two weeks after Hurricane Jeanne's heavy rains induced the flooding. Some of the water may have been present before the floods, but the recent influx of water has pushed the lake far beyond its shores. According to the Associated Press, the lake has covered the primary road connecting Gonaives to Haiti's capital, Port-au-Prince, with over a meter (four feet) of water, making food delivery difficult. The road can be seen here, a blurred white line under the dark blue water. The grey area at the end of the road near the shore is Gonaives. These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]). They were made by combining the infrared, near infrared, and red wavelengths (ASTER bands 4, 3, & 2). In this treatment, bare land appears pink, healthy croplands are light green, and concrete structures such as city buildings have a grey or deep purple tone. NASA image created by Jesse Allen, Earth Observatory using data obtained courtesy of the of NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ]. |
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Floods in Gonaives, Haiti
| Title |
Floods in Gonaives, Haiti |
| Description |
The floods that claimed the lives of at least 1,500 Haitians and left as many missing, also filled a large lake basin outside of Gonaives. The basin, which was a dry dust bowl on August 8, 2001, was still completely covered with water on October 3, 2004, two weeks after Hurricane Jeanne's heavy rains induced the flooding. Some of the water may have been present before the floods, but the recent influx of water has pushed the lake far beyond its shores. According to the Associated Press, the lake has covered the primary road connecting Gonaives to Haiti's capital, Port-au-Prince, with over a meter (four feet) of water, making food delivery difficult. The road can be seen here, a blurred white line under the dark blue water. The grey area at the end of the road near the shore is Gonaives. These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]). They were made by combining the infrared, near infrared, and red wavelengths (ASTER bands 4, 3, & 2). In this treatment, bare land appears pink, healthy croplands are light green, and concrete structures such as city buildings have a grey or deep purple tone. NASA image created by Jesse Allen, Earth Observatory using data obtained courtesy of the of NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ]. |
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Floods in Kansas and Missour
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| Title |
Floods in Kansas and Missouri |
| Description |
Floods that started with heavy rain on June 26, 2007, still surrounded parts of Coffeyville, Kansas, on July 9, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) flying on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image. Coffeyville was flooded on July 1, when the swollen Verdigris River burst through a levee. Water swamped neighborhoods and businesses, including the Coffeyville Resources Refinery. Though the refinery had been shut down in anticipation of the flooding, it leaked more than 42,000 gallons of crude oil into the Verdigris River, reported the Environment News Service. [ http://www.ens-newswire.com/ens/jul2007/2007-07-03-01.asp ] The Environmental Protection Agency [ http://www.epa.gov/region7/cleanup/coffeyville/index.html ] was coordinating with Coffeyville Resources to clean up the spill and to ensure that oil did not contaminate drinking water downstream. In these false-color images, the city of Coffeeville is silver and white. Vegetation is red, bare earth is pale gray, and water is dark blue. The Coffeyville Resources Refinery is the concentrated mass of silver, accented with large, white circular storage tanks, northeast of the city. In the top image, the refinery is surrounded by a pool of blue flood water. The lower image, taken on May 19, 2007, shows the area in normal conditions. Downstream from the refinery (to the south) is a grid of streets surrounded by plant-covered land. A few clusters of buildings line the larger streets, but few other large buildings are evident in the area, indicating that this is probably a residential neighborhood. Residual oil-tainted water creates traces of dark blue in the eastern half of the neighborhood. Smudges of blue west of the refinery indicate that the river flooded this part of the city as well. Beyond these areas, the flooded river seemed to remain confined behind levees on its flood plain. The high levees resemble dark red walls hemming in defined geometric shapes, which are filled with water in the top image, but are mud-gray in the lower image. Additional flooding along the Verdigris River is shown in the large image. A broader view [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14353 ] of floods in southeastern Kansas is available in the Natural Hazards section of the Earth Observatory. You can download a 15-meter-resolution KMZ file of Coffeyville [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/kansas_ast_2007187.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Floods in Kansas and Missour
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| Title |
Floods in Kansas and Missouri |
| Description |
Floods that started with heavy rain on June 26, 2007, still surrounded parts of Coffeyville, Kansas, on July 9, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) flying on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image. Coffeyville was flooded on July 1, when the swollen Verdigris River burst through a levee. Water swamped neighborhoods and businesses, including the Coffeyville Resources Refinery. Though the refinery had been shut down in anticipation of the flooding, it leaked more than 42,000 gallons of crude oil into the Verdigris River, reported the Environment News Service. [ http://www.ens-newswire.com/ens/jul2007/2007-07-03-01.asp ] The Environmental Protection Agency [ http://www.epa.gov/region7/cleanup/coffeyville/index.html ] was coordinating with Coffeyville Resources to clean up the spill and to ensure that oil did not contaminate drinking water downstream. In these false-color images, the city of Coffeeville is silver and white. Vegetation is red, bare earth is pale gray, and water is dark blue. The Coffeyville Resources Refinery is the concentrated mass of silver, accented with large, white circular storage tanks, northeast of the city. In the top image, the refinery is surrounded by a pool of blue flood water. The lower image, taken on May 19, 2007, shows the area in normal conditions. Downstream from the refinery (to the south) is a grid of streets surrounded by plant-covered land. A few clusters of buildings line the larger streets, but few other large buildings are evident in the area, indicating that this is probably a residential neighborhood. Residual oil-tainted water creates traces of dark blue in the eastern half of the neighborhood. Smudges of blue west of the refinery indicate that the river flooded this part of the city as well. Beyond these areas, the flooded river seemed to remain confined behind levees on its flood plain. The high levees resemble dark red walls hemming in defined geometric shapes, which are filled with water in the top image, but are mud-gray in the lower image. Additional flooding along the Verdigris River is shown in the large image. A broader view [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14353 ] of floods in southeastern Kansas is available in the Natural Hazards section of the Earth Observatory. You can download a 15-meter-resolution KMZ file of Coffeyville [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/kansas_ast_2007187.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Angora Fire
| Title |
Angora Fire |
| Description |
South of Lake Tahoe, the Angora Fire burned more than 3,000 acres in late June 2007. The fire, which started from an illegal campfire, destroyed more than 250 homes in the region, and left a huge charcoal-colored burn scar across the landscape. This image of the aftermath of the fire was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite on June 29. The streets and communities south of the lake are light gray and white. The burn scar is centered in the scene, and it is clear how the fire engulfed residential areas along its eastern margin (for example, near bottom center). NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Angora Fire
| Title |
Angora Fire |
| Description |
On the weekend of June 23, 2007, a wildfire broke out south of Lake Tahoe, which stretches across the California-Nevada border. By June 28, the Angora Fire [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14323 ] had burned more than 200 homes and forced some 2,000 residents to evacuate, according to The Seattle Times and the Central Valley Business Times. On June 27, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite captured this image of the burn scar left by the Angora fire. The burn scar is dark gray, or charcoal. Water bodies, including the southern tip of Lake Tahoe and Fallen Leaf Lake, are pale silvery blue, the silver color a result of sunlight reflecting off the surface of the water. Vegetation ranges in color from dark to bright green. Streets are light gray, and the customary pattern of meandering residential streets and cul-de-sacs appears throughout the image, including the area that burned. The burn scar shows where the fire obliterated some of the residential areas just east of Fallen Leaf Lake. According to news reports, the U.S. Forest Service had expressed optimism about containing the fire within a week of the outbreak, but a few days after the fire started, it jumped a defense, forcing the evacuation of hundreds more residents. Strong winds that had been forecast for June 27, however, did not materialize, allowing firefighters to regain ground in controlling the blaze. On June 27, authorities hoped that the fire would be completely contained by July 3. According to estimates provided in the daily report from the National Interagency Fire Center, [ http://www.nifc.gov/information.html ] the fire had burned 3,100 acres (about 12.5 square kilometers) and was about 55 percent contained as of June 28. Some mandatory evacuations remained in effect. You can download a 15-meter-resolution KMZ file of the Angora fire [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/tahoe_ast_2007178.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Ash Plume from Karymsky
| Title |
Ash Plume from Karymsky |
| Description |
The Karymsky Volcano in far northeastern Russia had been erupting several times a day for about a week prior to emitting this ash plume on June 19, 2006. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this false-color image. In this picture, red indicates vegetation, which is lush around the volcano but very sparse on its slopes. The water of Karymskoye Lake appears in blue. The volcano's barren sides are dark gray, and the volcanic plume and nearby haze appear in white or gray. Karymsky Volcano is the most active volcano in the eastern volcanic zone of the Kamchatka Peninsula. The volcano is composed of alternating layers of hardened lava, ash, and rocks. Historical eruptions have involved explosive eruptions of lava fragments and the release of volcanic gases. At the time of the June 19 eruption, Karymsky had an alert status of orange, indicating that a small ash eruption was expected or confirmed, but not likely to exceed an altitude greater than 7,620 meters (25,000 feet) above sea level. NASA image created by Jesse Allen, Earth Observatory, using expedited ASTER data provided the NASA/GSFC/MITI/ERSDAC/JAROS and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Bialowieza National Park
| Title |
Bialowieza National Park |
| Description |
Biolowieza National Park lies on the border between Poland and Belarus. It was first established as a park in 1932, and restored in 1947 in the wake of the Second World War. The park was also declared a biosphere reserve in 1977. It is also a transboundary World Heritage site in conjunction with the Belovezhskaya Pushcha Biosphere Reserve adajacent to it on the Belarus side of the border. It is a section carved out of the much larger Bialowieza Forest: the park is slightly less than one fifth of the forest area. The Biolowieza Forest is a unique ecosystem: not only does it contain a rare European lowland old growth forest, but it also lies in a border zone between the boreal and temperate climate zones. Within its borders are some of the southernmost stands of boreal species such as the norway spruce. It also contains temperate species at their northernmost limits, such as sessile oak. The forest also contains a complex mosaic of plants and animals, including forest ungulates, birds of prey, and a wide assortment of vascular plants, mosses, lichens, and fungi. It is also the site of successful reintroduction of species including the European bison and beaver. The preservation of this area owes a great deal to its protection over several centuries from leading figures in central Europe, from Polish kings, Lithuanian princes and dukes, and the Russian Tsars. Their interest in maintaining the land focused on its leisure use as hunting grounds, but this also provided protection from most agricultural use and land clearing. Its national park status in the 20th century has further protected it from development, though areas around it have been subjected to conversion to commercial lumber industry. In the summer of 2003, a new management plan for the Bialowieza Forest called for removing trees in an effort to contain infestations of bark beetles. These new policies have been the subject of heated debate in the forestry and ecology communities, with conservationists accusing the government of clearing the most valuable timber under a dubious guise of forest protection, while government officials cite the plan as an example of sustainable forestry practices. Forest clearing and poor land practices in the adjacent land in Belarus, such as felling trees that are hosts for the bark beetle and failing to remove the logs promptly, continue to be a source of growing concern to ecologists as these last stands of primeval European forest are turned to commercial land use and pressures. In this scene, acquired on April 29, 2002, by the Terra satellite's ASTER instrument, many of these features can be discerned. The old palace grounds are quite evident, as are the clear cut areas in the Biolowieza Forest outside the park, whose boundaries are partially defined by the Lesna River and the international border with Belarus. The international boundary appears as the linear feature to the top right of this image where forest has been cleared along the border. This, image was created by combining red, near-infrared and green wavelengths (ASTER VNIR bands 2, 3, and 1). Image created from data collected by NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team Data processed by the American Museum of Natural History's Science Bulletins |
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Bockfjorden
| Title |
Bockfjorden |
| Description |
Far north within the Arctic Circle off the northern coast of Norway lies a small chain of islands known as Svalbard. These craggy islands have been scoured into shape by ice and sea. The effect of glacial activity can be seen in this image of the northern tip of the island of Spitsbergen. Here, glaciers have carved out a fjord, a U-shaped valley that has been flooded with sea water. Called Bockfjorden, the fjord is located at almost 80 degrees north, and it is still being affected by glaciers. The effect is most obvious in this image in the tan layer of silty freshwater that floats atop the denser blue water of the Arctic Ocean. The fresh water melts off land-bound glaciers and flows over the sandstone, collecting fine red-toned silt. In this image, the tan-colored fresh water flows northward up the fjord and is being pushed to the east side of the fjord by the rotation of the Earth. Glaciers here and elsewhere on Spitsbergen are cold bottom glaciers, which means that they are frozen to the ground rather than floating on top of a thin layer of melt water. The glaciers are also land glaciers since their terminus (end) lies on land, rather than floating on the water (a tidewater glacier). Land glaciers grow and retreat slowly, balancing fresh snow with the melting and draining of old ice. Their rate of growth or retreat can be affected by global warming. In most cases, including the glaciers around Bockfjorden, global warming has caused glaciers to retreat from increased melting. On the eastern side of Svalbard, however, glaciers are growing from enhanced snowfall. The reason for this pattern remains only one of many intriguing unanswered questions of Arctic science in the islands. The Advanced Spaceborne Thermal Emission and Reflection Radiometer, (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this false-color image on June 26, 2001. The image was created by combining near-infrared, red, and green wavelenghts (ASTER bands 3, 2, & 1 respectively). NASA image created by Jesse Allen, Earth Observatory, using data obtained from the Goddard Earth Sciences DAAC [ http://daac.gsfc.nasa.gov/ ] courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Brins Fire Near Sedona, AZ
| Title |
Brins Fire Near Sedona, AZ |
| Description |
Northeast of Sedona, Arizona, the Brins Fire continued to threaten parts of Oak Creek Canyon on June 23, 2006. This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite shows the Brins Fire and the town of Sedona. The image doesn't appear exactly like a digital photo because it uses ASTER's observations of shortwave and near-infrared light to make the burned area stand out from the unburned vegetation. Vegetation appears red, the burn scar appears charcoal, and bare ground or thinly vegetated ground appears tan or yellow. Route 89, sections of which have been closed by the fire, runs in a gray ribbon through Sedona and Oak Creek Canyon. The haze in the scene may be a mixture of smoke and thin clouds. According to reports from the National Interagency Fire Center [ http://www.nifc.gov/nicc ] on June 26, the Brins Fire was threatening residences, commercial structures, endangered species habitat, and the Oak Creek watershed and Scenic Highway. On that date, the agency estimated the fire was 4,222 acres and about 50 percent contained. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Floods in the Midwestern Uni
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| Title |
Floods in the Midwestern United States |
| Description |
August 2007 was the wettest month ever recorded for many places in Minnesota, Iowa, and Wisconsin, with rainfall totals ranging from 23.86 inches in Hokah, Minnesota, to 12.79 inches in Winona Dam, Minnesota, said the National Weather Service. [ http://www.crh.noaa.gov/crnews/display_story.php?wfo=arx&storyid=9990&source=0 ] While the entire month was rainy, much of the rain fell on August 18-20, when several thunderstorms rolled across the region. The thunderstorms triggered disastrous flooding in several Midwest communities, including La Crosse, Wisconsin. A little over 10 inches of rain fell in La Crosse in the 24-hour period that spanned August 18 and August 19, and flash floods resulted. Combined with rains from the rest of August, this rainfall let La Crosse set a new monthly precipitation record of 17 inches. By August 27, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image, the floods had largely retreated, though visible signs of flooding remained. Compared to the lower image, acquired on September 7, 2006, the landscape to the west of the Mississippi River is pocked with pools of water. The city of La Crosse, the bright white and gray grid on the east side of the river, appears to have dried out. The city appears much as it did nearly a year earlier with no visible sign of flooding. You can download a 15-meter-resolution KMZ file of the 2007 image of La Crosse [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Sep2007/lacrosse_ast_2007239.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Floods in the Midwestern Uni
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| Title |
Floods in the Midwestern United States |
| Description |
August 2007 was the wettest month ever recorded for many places in Minnesota, Iowa, and Wisconsin, with rainfall totals ranging from 23.86 inches in Hokah, Minnesota, to 12.79 inches in Winona Dam, Minnesota, said the National Weather Service. [ http://www.crh.noaa.gov/crnews/display_story.php?wfo=arx&storyid=9990&source=0 ] While the entire month was rainy, much of the rain fell on August 18-20, when several thunderstorms rolled across the region. The thunderstorms triggered disastrous flooding in several Midwest communities, including La Crosse, Wisconsin. A little over 10 inches of rain fell in La Crosse in the 24-hour period that spanned August 18 and August 19, and flash floods resulted. Combined with rains from the rest of August, this rainfall let La Crosse set a new monthly precipitation record of 17 inches. By August 27, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image, the floods had largely retreated, though visible signs of flooding remained. Compared to the lower image, acquired on September 7, 2006, the landscape to the west of the Mississippi River is pocked with pools of water. The city of La Crosse, the bright white and gray grid on the east side of the river, appears to have dried out. The city appears much as it did nearly a year earlier with no visible sign of flooding. You can download a 15-meter-resolution KMZ file of the 2007 image of La Crosse [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Sep2007/lacrosse_ast_2007239.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Central Pyrenees
| Title |
Central Pyrenees |
| Description |
The Alps may be more famous, but the Pyrenees have been around much longer—tens of millions of years longer, in fact. These mountains formed between 100 and 150 million years ago when the landmass that Spain occupies pushed into the one that France occupies. The mountains have served as a natural barrier between the Iberian Peninsula (Spain and Portugal) and the rest of Europe ever since. Stretching east to west across 430 square kilometers (267 miles), the Pyrenees fall mostly within Spain's borders, but also pass into the independent state of Andorra. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA 's Terra [ http://terra.nasa.gov ] satellite captured this image of part of the Central Pyrenees—the highest part of the range—on August 1, 2000. In this false-color image, clouds appear white, snow appears pale blue, vegetation appears green, and bare ground appears as either pink or dark, bluish-purple. Water on the ground appears dark blue (or nearly black). In this shot, the vegetated areas are mostly to the north, and the peaks to the south are mostly bare rock. In the large image, patches of dark purple that are visible along rivers and in valley floors are probably developed areas. As mountain peaks rise higher, the land they support rises above the treeline (the topmost elevation where trees can grow). At even higher altitudes, hardly any plants can survive at all, so the highest mountain peaks show just snow or bare rock. This mountain chain owes its ruggedness to granite, a volcanic rock that erodes slowly. The mountains also contain other rocks: gneiss and limestone. Glaciers didn't act on the Pyrenees as extensively as they did on the Alps, so these mountains don't sport big lakes left behind by glaciers. They do have water, however, including many small lakes and waterfalls. NASA image created by Jesse Allen, Earth Observatory, using ASTER data made available by NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Chilean Lake Disappears
| Title |
Chilean Lake Disappears |
| Description |
In May 2007, the Chilean Forestry Corporation discovered that a lake in the Southern Patagonia Icefield in the Chilean Andes had disappeared. Chilean glaciologists had observed the 20,000-square-meter (roughly 215,000-squre-foot) lake, which was located between the tongues of the Glaciar Témpanos and Glaciar Bernardo, in March. (Glaciar is Spanish for "glacier.") Two months later, nothing remained except a 30-meter- (100-foot-) deep crater and some stranded ice that had once floated on the water's surface. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite captured the top image on June 23, 2007, showing a crater that the lake had occupied. In this image, the crater lies mostly in shadow, due to the low angle of the Sun during the Southern Hemisphere's winter. Despite the shadows, contour lines around the lake show where the ground level is lower than the surroundings. East of the drained lake, water still appears near the tongue of Glaciar Bernardo. In this image, made from a combination of visible and infrared light detected by ASTER, red indicates vegetation, and patches of red peek through the snow cover. ASTER acquired the bottom image on April 4, 2007, when the lake was still in place. In this image—acquired in the Chilean autumn—both the lake and a nearby tributary appear full, shown by the blue-tinted water. Vibrant red, lush vegetation covers the landscape. Although the sudden draining of a lake is rare, it is not unheard of. One explanation that scientists proposed was an earthquake in the region that measured 6.2 on the Richter scale. Earthquakes can open up fissures in the rock, giving water an escape route. Another explanation was more prosaic: melting. Blocks of ice dam many glacial lakes, and when the ice melts, the lake can drain away. Sometimes a lake can drain in a rapid deluge, known as a glacial lake outburst flood. After flying over the region in late June 2007, scientists from Centro de Estudios Cientificos (CECS) and the Chilean Navy concluded that the likely culprit for the lake's disappearance was such a flood. Dr. Andrés Rivera, a glaciologist from CECS, described the flow. "The lake's water flowed to the north along the western margin of Glaciar Bernardo and into a big hole, [ http://www.imaginaccion.cl/cecs.html ] where the water went down into a glacier tunnel in the direction to Bernardo Fjord," he said. Bernardo Fjord empties into the Pacific Ocean. You can also download a 15-meter-resolution KMZ file of the region around the "missing" lake [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/lagotempanos_ast_2007174.kmz ], including both April 4 and June 23, 2007, images, suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Chilean Lake Disappears
| Title |
Chilean Lake Disappears |
| Description |
In May 2007, the Chilean Forestry Corporation discovered that a lake in the Southern Patagonia Icefield in the Chilean Andes had disappeared. Chilean glaciologists had observed the 20,000-square-meter (roughly 215,000-squre-foot) lake, which was located between the tongues of the Glaciar Témpanos and Glaciar Bernardo, in March. (Glaciar is Spanish for "glacier.") Two months later, nothing remained except a 30-meter- (100-foot-) deep crater and some stranded ice that had once floated on the water's surface. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite captured the top image on June 23, 2007, showing a crater that the lake had occupied. In this image, the crater lies mostly in shadow, due to the low angle of the Sun during the Southern Hemisphere's winter. Despite the shadows, contour lines around the lake show where the ground level is lower than the surroundings. East of the drained lake, water still appears near the tongue of Glaciar Bernardo. In this image, made from a combination of visible and infrared light detected by ASTER, red indicates vegetation, and patches of red peek through the snow cover. ASTER acquired the bottom image on April 4, 2007, when the lake was still in place. In this image—acquired in the Chilean autumn—both the lake and a nearby tributary appear full, shown by the blue-tinted water. Vibrant red, lush vegetation covers the landscape. Although the sudden draining of a lake is rare, it is not unheard of. One explanation that scientists proposed was an earthquake in the region that measured 6.2 on the Richter scale. Earthquakes can open up fissures in the rock, giving water an escape route. Another explanation was more prosaic: melting. Blocks of ice dam many glacial lakes, and when the ice melts, the lake can drain away. Sometimes a lake can drain in a rapid deluge, known as a glacial lake outburst flood. After flying over the region in late June 2007, scientists from Centro de Estudios Cientificos (CECS) and the Chilean Navy concluded that the likely culprit for the lake's disappearance was such a flood. Dr. Andrés Rivera, a glaciologist from CECS, described the flow. "The lake's water flowed to the north along the western margin of Glaciar Bernardo and into a big hole, [ http://www.imaginaccion.cl/cecs.html ] where the water went down into a glacier tunnel in the direction to Bernardo Fjord," he said. Bernardo Fjord empties into the Pacific Ocean. You can also download a 15-meter-resolution KMZ file of the region around the "missing" lake [ http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/lagotempanos_ast_2007174.kmz ], including both April 4 and June 23, 2007, images, suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Chiliques Volcano, Chile
| Title |
Chiliques Volcano, Chile |
| Description |
The Chiliques volcano, which hasn't erupted in at least 10,000 years, is now showing signs of life. This pair of images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) shows the volcano in visible and nrea-infrared light (top) and thermal infrared (lower). The thermal infrared image shows hot spots in the summit crtaer caused by magma just under the surface. For more information, read: Dormant Volcanoes Shows Signs of Life [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www.jpl.nasa.gov/images/earth/volcano/index.html ] Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://asterweb.jpl.nasa.gov/ ] |
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Chiliques Volcano, Chile
| Title |
Chiliques Volcano, Chile |
| Description |
The Chiliques volcano, which hasn't erupted in at least 10,000 years, is now showing signs of life. This pair of images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) shows the volcano in visible and nrea-infrared light (top) and thermal infrared (lower). The thermal infrared image shows hot spots in the summit crtaer caused by magma just under the surface. For more information, read: Dormant Volcanoes Shows Signs of Life [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www.jpl.nasa.gov/images/earth/volcano/index.html ] Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://asterweb.jpl.nasa.gov/ ] |
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Gosses Bluff, Northern Terri
…
| Title |
Gosses Bluff, Northern Territory, Australia |
| Description |
Gosses Bluff is one of the most significant impact structures in the world. Located about 205 kilometers west of Alice Springs, in Northern Territory, Australia, the crater has been largely preserved in the dry, lightly vegetated region. Gosses Bluff was probably formed by the impact of a large comet or meteorite about 142 million years ago. Traveling at a rate of about 40 kilometers per second, the object slammed into the surface of the Earth, leaving a crater that was about 22 kilometers in diameter. The structure we now see is the result of erosion—the crater would originally have had an outer raised rim and a prominent central peak. The core of the original crater is now represented by a ring of low hills, seen in the lower left side of the image. The ghostly remnants of the outer rim are visible from space in astronaut photos [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=15317 ] as a faint circle around the crater that is seen here. This perspective view was created by draping a false-color composite image over a digital elevation model. These data were acquired by the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) instrument aboard the Terra satellite on October 11, 2003. The composite image uses shortwave infrared, near infrared, and green wavelengths (ASTER bands 7, 3, & 1), while the digital elevation was computed from the stereo pair data channels. Surface elevations are shown true to scale without vertical exaggeration. NASA image created by Jesse Allen, Earth Observatory. ASTER data and elevation imagery courtesy of Michael Abrams and the MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team. |
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Grassfire in Iceland
| Title |
Grassfire in Iceland |
| Description |
At the end of March 2006, a grassfire broke out in western Iceland, perhaps as a result of a smoldering cigarette butt. Although this area near the coast to the northwest of the country's capital, Reykjavik, is typically very wet, a period of persistent north winds dried out the grass and made it flammable. The fire burned for several days, threatening farms and livestock and resulting in Iceland's largest fire in its recorded history. This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite was captured on April 6, 2006. The burned area appears as a large brownish-charcoal splotch in the center of the image. The fire started inland and burned all the way to the coast. This is a false-color image, and unburned vegetation appears red, clouds appear white, and the Atlantic Ocean (image left) appears nearly black. Several partially ice-covered lakes are scattered across the burned landscape, these lakes appear light blue. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
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Colima Erupts
| Title |
Colima Erupts |
| Description |
A series of explosive eruptions have thundered from the Colima Volcano, Mexico?s most active volcano. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the Colima volcano on June 3, 2005, just hours after two spectacular eruptions rumbled from the volcano. Two days later, on June 5, Colima experienced its strongest eruption in 20 years when it sent a dark column of ash more than five kilometers into the atmosphere at a rate of roughly 30 kilometers per hour, reports the Universidad de Colima?s Observatorio Vulcanologico [ http://www.ucol.mx/volcan/ ]. Colima also erupted on May 24 and May 30, and the ash from these and the June 2 and June 3 eruptions is clearly visible in the top image. A grey river of ash and rock flows down the west side of the peak, covering the vegetation that was visible on February 6, 2003, lower image. In these false-color images, the dense vegetation that surrounds the volcano is red. A light dusting of ash blankets the trees on the southeast side of the volcano, and fresh flows stream down all sides of the volcano. Because of its resemblance to the cloud in the upper right corner of the image, the cloud that rests over the summit of the volcano is probably a regular cloud, though it could also be a plume of steam. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
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Colima Erupts
| Title |
Colima Erupts |
| Description |
A series of explosive eruptions have thundered from the Colima Volcano, Mexico?s most active volcano. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the Colima volcano on June 3, 2005, just hours after two spectacular eruptions rumbled from the volcano. Two days later, on June 5, Colima experienced its strongest eruption in 20 years when it sent a dark column of ash more than five kilometers into the atmosphere at a rate of roughly 30 kilometers per hour, reports the Universidad de Colima?s Observatorio Vulcanologico [ http://www.ucol.mx/volcan/ ]. Colima also erupted on May 24 and May 30, and the ash from these and the June 2 and June 3 eruptions is clearly visible in the top image. A grey river of ash and rock flows down the west side of the peak, covering the vegetation that was visible on February 6, 2003, lower image. In these false-color images, the dense vegetation that surrounds the volcano is red. A light dusting of ash blankets the trees on the southeast side of the volcano, and fresh flows stream down all sides of the volcano. Because of its resemblance to the cloud in the upper right corner of the image, the cloud that rests over the summit of the volcano is probably a regular cloud, though it could also be a plume of steam. NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
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Colima's Long Eruption
| Title |
Colima's Long Eruption |
| Description |
, University of Hawaii Manoa. ASTER image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ], The Colima Volcano part of a complex of volcanoes that forms the center of the Western Mexico Volcanic Belt. Rising 3,850 meters above the forested valley around the Nevado National Park, Colima is one of Mexico's most active volcanoes. Most recently, on September 28, 2004, a new lava dome began to rise from Colima's summit crater. By September 30, block and ash flows—an avalanche of hot volcanic rock—began streaming down the mountain, and lava bubbled out starting on October 1. The eruption had not stopped by October 5, when the Smithsonian Global Volcanism Program [ http://www.volcano.si.edu/reports/usgs/index.cfm ] released their most recent report. The current eruption is a continuation of a longer eruptive phase. From February 2002 to February 2003, the volcano erupted almost continuously and has burst forth with several smaller eruptions since that time. In one of Colima's quieter moments, on January 17, 2004, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) aboard NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the above false-color image (Bands 3-2-1). The large snow-covered mountain to the north is Nevado de Colima. This older edifice dwarfs the younger and historically active Colima volcano to the south, shown here with a minor steam plume. Several lava flows from previous eruptions can be seen emanating from the Colima volcano summit area. ASTER is not the only instrument that has proven useful in monitoring volcanoes from space. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] and Aqua [ http://aqua.nasa.gov/ ] satellites detects thermal anomalies like volcanic hotspots and fires. MODIS data are entered into the MODVOLC system, which automatically calculates the heat output from the volcano. This plot shows the 2002-2003 eruptive phase as well as later sporadic events. The first alert occurred on February 16, 2002, roughly coincident with the appearance of new lava on February 14, 2002, and the last alert of the main 2002-2003 eruptive phase was on January 25, 2003, when lava effusion was beginning to diminish. Alerts in August through December 2003, and one in February 2004, represent the periodic explosive activity that has followed the 2002-2003 lava effusion at Colima. The alert dated August 29, 2003, was acquired within hours of a large explosion on August 28, which produced a series of pyroclastic flows down Colima's flanks. To read more about the use of MODIS to monitor volcanoes, please read Sensing Remote Volcanoes [ http://earthobservatory.nasa.gov/Study/monvoc/ ]. Eruption information from the Global Volcanism Network. Satellite data provided by the HIGP Thermal Alerts Team [ http://modis.higp.hawaii.edu ] |
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Colima's Long Eruption
| Title |
Colima's Long Eruption |
| Description |
, University of Hawaii Manoa. ASTER image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ], The Colima Volcano part of a complex of volcanoes that forms the center of the Western Mexico Volcanic Belt. Rising 3,850 meters above the forested valley around the Nevado National Park, Colima is one of Mexico's most active volcanoes. Most recently, on September 28, 2004, a new lava dome began to rise from Colima's summit crater. By September 30, block and ash flows—an avalanche of hot volcanic rock—began streaming down the mountain, and lava bubbled out starting on October 1. The eruption had not stopped by October 5, when the Smithsonian Global Volcanism Program [ http://www.volcano.si.edu/reports/usgs/index.cfm ] released their most recent report. The current eruption is a continuation of a longer eruptive phase. From February 2002 to February 2003, the volcano erupted almost continuously and has burst forth with several smaller eruptions since that time. In one of Colima's quieter moments, on January 17, 2004, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) aboard NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the above false-color image (Bands 3-2-1). The large snow-covered mountain to the north is Nevado de Colima. This older edifice dwarfs the younger and historically active Colima volcano to the south, shown here with a minor steam plume. Several lava flows from previous eruptions can be seen emanating from the Colima volcano summit area. ASTER is not the only instrument that has proven useful in monitoring volcanoes from space. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] and Aqua [ http://aqua.nasa.gov/ ] satellites detects thermal anomalies like volcanic hotspots and fires. MODIS data are entered into the MODVOLC system, which automatically calculates the heat output from the volcano. This plot shows the 2002-2003 eruptive phase as well as later sporadic events. The first alert occurred on February 16, 2002, roughly coincident with the appearance of new lava on February 14, 2002, and the last alert of the main 2002-2003 eruptive phase was on January 25, 2003, when lava effusion was beginning to diminish. Alerts in August through December 2003, and one in February 2004, represent the periodic explosive activity that has followed the 2002-2003 lava effusion at Colima. The alert dated August 29, 2003, was acquired within hours of a large explosion on August 28, which produced a series of pyroclastic flows down Colima's flanks. To read more about the use of MODIS to monitor volcanoes, please read Sensing Remote Volcanoes [ http://earthobservatory.nasa.gov/Study/monvoc/ ]. Eruption information from the Global Volcanism Network. Satellite data provided by the HIGP Thermal Alerts Team [ http://modis.higp.hawaii.edu ] |
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Deadly Earthquake, Xianjing
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| Title |
Deadly Earthquake, Xianjing Province, China |
| Description |
A destructive earthquake of magnitude 6.4 rattled China?s Xinjiang province at 10:04 AM (local time) on February 24, 2003. Over 250 people were killed. This remote, flat, and mostly featureless area of western China (called the Tarim Basin by geologists) is different from most other regions with frequent earthquakes. Typical seismically active areas are mountainous, like Alaska and coastal California, and lie along the boundaries of tectonic plates. In contrast, the Tarim Basin (which lies on the Eurasian Plate) remains flat while it is being squeezed by the motion of the Indian Plate?which is 1000 km (620 miles) away. Instead of deforming into belts of mountain ranges, the Tarim Basin is transmitting force applied by the Indian Plate to the interior of Asia, where the Tian Shan mountains are rising. The Tian Shan can be seen at the top edge of the large image. The approximate epicenter of the earthquake is represented by a white dot in this image, acquired on August 29, 2001, (before the earthquake) by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). ASTER is an instrument aboard NASA's Terra [ http://terra.nasa.gov/ ] satellite. The false-color image combines near-infrared, red, and green wavelengths. Crops, almost certainly irrigated, appear red in this scene, while barren landscape appears brown. Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://asterweb.jpl.nasa.gov/ ] |
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Deforestation in Brazil
| Title |
Deforestation in Brazil |
| Description |
This image shows the extent of deforestation in the state of Rondonia, Brazil. Acquired by the Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on August 24, 2000, the false-color image combines near-infrared, red, and green light. Tropical rainforest appears bright red, while pale red and brown areas represent cleared land. Black and gray areas have probably been recently burned. The Jiparaná River appears blue. With a maximum spatial resolution of 15 meters, ASTER does not produce imagery as detailed as the IKONOS satellite, which has a maximum resolution of one meter. Compare the above image with IKONOS data [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4561 ] from the same area. The somewhat lower resolution ASTER data is not as detailed, but provides a better overview, and ASTER can acquire data over a particular region more often than IKONOS. Other satellite instruments, such as the Sea-viewing Wide Field-of-View Sensor (SeaWiFS), give even broader and more frequent coverage, as shown by this true-color image of Rondonia. [ http://visibleearth.nasa.gov/cgi-bin/viewrecord?3841 ] Image courtesy NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://asterweb.jpl.nasa.gov/ ] |
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Diverse Terrain of Iran's Da
…
| Title |
Diverse Terrain of Iran's Dasht-e Lut |
| Description |
Roughly 480 by 320 kilometers (300 by 200 miles), Dasht-e Lut is a large salt desert in southeastern Iran. The desert fills a low basin that stretches southward from the Khorasan province into the Kerman province. Although the entire salt desert has just one name, it has more than one appearance. These natural-color images, captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite show landscapes so different, one can scarcely imagine they come from the same part of the world, let alone the same desert basin. The picture on the left shows part of the central portion of Dasht-e Lut. The strong diagonal lines result from wind erosion that has carved deep troughs and sharp ridges into the landscape. These wind-sculpted ridges are known as yardangs, and geologic research [ http://disc.gsfc.nasa.gov/geomorphology/GEO_8/GEO_PLATE_E-19.HTML ] has determined that Iran contains some of the world's largest yardangs. ASTER acquired this image on May 13, 2006. The picture on the right shows part of the southeastern portion of Dasht-e Lut. This area consists of sand, and it contains some of the world's tallest dunes, some reaching a height of 300 meters (1,000 feet). In this image, the white areas are saltpans—the aftermath of water that drained into the basins among the dunes and later evaporated. Golden dunes make swirling pattenrs across the image, becoming less tightly packed in the bottom of the scene. ASTER acquired this image on July 17, 2003. Dasht-e Lut's dramatic landscapes are a popular remote-sensing target. Astronauts on the International Space Station photographed [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17226 ] salt lakes from Dasht-e Lut and nearby faulted rocks on February 28, 2006. NASA images created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Diverse Terrain of Iran's Da
…
| Title |
Diverse Terrain of Iran's Dasht-e Lut |
| Description |
Roughly 480 by 320 kilometers (300 by 200 miles), Dasht-e Lut is a large salt desert in southeastern Iran. The desert fills a low basin that stretches southward from the Khorasan province into the Kerman province. Although the entire salt desert has just one name, it has more than one appearance. These natural-color images, captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite show landscapes so different, one can scarcely imagine they come from the same part of the world, let alone the same desert basin. The picture on the left shows part of the central portion of Dasht-e Lut. The strong diagonal lines result from wind erosion that has carved deep troughs and sharp ridges into the landscape. These wind-sculpted ridges are known as yardangs, and geologic research [ http://disc.gsfc.nasa.gov/geomorphology/GEO_8/GEO_PLATE_E-19.HTML ] has determined that Iran contains some of the world's largest yardangs. ASTER acquired this image on May 13, 2006. The picture on the right shows part of the southeastern portion of Dasht-e Lut. This area consists of sand, and it contains some of the world's tallest dunes, some reaching a height of 300 meters (1,000 feet). In this image, the white areas are saltpans—the aftermath of water that drained into the basins among the dunes and later evaporated. Golden dunes make swirling pattenrs across the image, becoming less tightly packed in the bottom of the scene. ASTER acquired this image on July 17, 2003. Dasht-e Lut's dramatic landscapes are a popular remote-sensing target. Astronauts on the International Space Station photographed [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17226 ] salt lakes from Dasht-e Lut and nearby faulted rocks on February 28, 2006. NASA images created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Diverse Terrain of Iran's Da
…
| Title |
Diverse Terrain of Iran's Dasht-e Lut |
| Description |
Roughly 480 by 320 kilometers (300 by 200 miles), Dasht-e Lut is a large salt desert in southeastern Iran. The desert fills a low basin that stretches southward from the Khorasan province into the Kerman province. Although the entire salt desert has just one name, it has more than one appearance. These natural-color images, captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite show landscapes so different, one can scarcely imagine they come from the same part of the world, let alone the same desert basin. The picture on the left shows part of the central portion of Dasht-e Lut. The strong diagonal lines result from wind erosion that has carved deep troughs and sharp ridges into the landscape. These wind-sculpted ridges are known as yardangs, and geologic research [ http://disc.gsfc.nasa.gov/geomorphology/GEO_8/GEO_PLATE_E-19.HTML ] has determined that Iran contains some of the world's largest yardangs. ASTER acquired this image on May 13, 2006. The picture on the right shows part of the southeastern portion of Dasht-e Lut. This area consists of sand, and it contains some of the world's tallest dunes, some reaching a height of 300 meters (1,000 feet). In this image, the white areas are saltpans—the aftermath of water that drained into the basins among the dunes and later evaporated. Golden dunes make swirling pattenrs across the image, becoming less tightly packed in the bottom of the scene. ASTER acquired this image on July 17, 2003. Dasht-e Lut's dramatic landscapes are a popular remote-sensing target. Astronauts on the International Space Station photographed [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17226 ] salt lakes from Dasht-e Lut and nearby faulted rocks on February 28, 2006. NASA images created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Heard Island Volcano
| Title |
Heard Island Volcano |
| Description |
Closer to Antarctica than any other major landmass, Heard Island sits in the far southern Indian Ocean two-thirds of the way from Madagascar to Antarctica. At the center of the remote, ice-covered island are the Big Ben massif, a large section of the Earth's crust that has been pushed up into a dense, rocky mountain by tectonic action, and an active volcano, Mawson Peak. The geologic activity that formed these features continues in the form of frequent eruptions from Mawson Peak. The volcano's current phase of activity began in May 2006, and it continued through December 2006, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this image. Made with both infrared and visible light, the image shows signs of volcanic activity on December 8, 2006. A glowing dot of red on Mawson Peak is thought to be a small lava lake in the summit crater. A fresh lava flow extends 700 meters east of the crater, creating a dark blue smudge on the otherwise even field of snow, which is blue-green in this false-color image. The rocky Big Ben Massif south of Mawson Peak similarly wrinkles the surface of the snow, though some of the apparent roughness may actually be icy clouds. Previous volcanic episodes, including those in 2000-2001 and 2003-2004, have lasted about a year. Due to its isolated location, Heard Island is rarely visited, and satellite imagery provides the only regular information on eruptive activity. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ]. Image interpretation provided by Matt Patrick and Anna Colvin, Michigan Technological University. [ http://www.mtu.edu/ ] |
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Heavy Rains and Floods in Au
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| Title |
Heavy Rains and Floods in Australia |
| Description |
Australia?s recent floods have breathed life into the normally dry, seasonal wetlands in the continent?s interior. Lake Yamma Yamma, shown above, is a shallow depression just west of the Cooper Creek floodplain in southwestern Queensland. The lake is usually a dry desert bowl, a playa lake, that collects water only when Cooper Creek floods. This year, Yamma Yamma has become an inland sea measuring 20 kilometers (12 miles) across. These images, taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://asterweb.jpl.nasa.gov/ ] (ASTER) on the Terra [ http://terra.nasa.gov/ ] satellite, contrast this year?s shorelines with the lake?s extent in 2001. Old shorelines show that the basin is not as full as it has been in the past, but Lake Yamma Yamma is clearly fuller this year than in 2001. Though the lake is shallow, it covers a large area and can hold a large volume of water. The influx of water into Lake Yamma Yamma and other interior lakes brings fish and a variety of birds to the outback. Pelicans, swans, ducks, and other bird species flock to the new water sources in the desert. Another sign of new life is the ring of red along the shore where new vegetation is growing. In this false-color infrared image, green plants appear red. Other lakes in Australia?s interior have also benefited from the floods. At the end of the Cooper Creek flood basin, Lake Eyre, Australia?s largest lake, has begun to fill for the first time in four years. The high-resolution images provided above are at ASTER?s full resolution of 15 meters per pixel. Image courtesy Jesse Allen based on data from the U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Heavy Rains and Floods in Au
…
| Title |
Heavy Rains and Floods in Australia |
| Description |
Australia?s recent floods have breathed life into the normally dry, seasonal wetlands in the continent?s interior. Lake Yamma Yamma, shown above, is a shallow depression just west of the Cooper Creek floodplain in southwestern Queensland. The lake is usually a dry desert bowl, a playa lake, that collects water only when Cooper Creek floods. This year, Yamma Yamma has become an inland sea measuring 20 kilometers (12 miles) across. These images, taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://asterweb.jpl.nasa.gov/ ] (ASTER) on the Terra [ http://terra.nasa.gov/ ] satellite, contrast this year?s shorelines with the lake?s extent in 2001. Old shorelines show that the basin is not as full as it has been in the past, but Lake Yamma Yamma is clearly fuller this year than in 2001. Though the lake is shallow, it covers a large area and can hold a large volume of water. The influx of water into Lake Yamma Yamma and other interior lakes brings fish and a variety of birds to the outback. Pelicans, swans, ducks, and other bird species flock to the new water sources in the desert. Another sign of new life is the ring of red along the shore where new vegetation is growing. In this false-color infrared image, green plants appear red. Other lakes in Australia?s interior have also benefited from the floods. At the end of the Cooper Creek flood basin, Lake Eyre, Australia?s largest lake, has begun to fill for the first time in four years. The high-resolution images provided above are at ASTER?s full resolution of 15 meters per pixel. Image courtesy Jesse Allen based on data from the U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hokkaido, Japan
| Title |
Hokkaido, Japan |
| Description |
Cities mingle with rugged hills and a dormant volcano in this image of Hokkaido, Japan. This three-dimensional image comes from observations made by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite on July 23, 2006. The view is toward the north and slightly east. Green indicates vegetation, beige and gray indicate bare ground, paved surfaces, or buildings, and dark blue indicates water. The water body at the top of the image is the Pacific Ocean. Now dormant, Mount Yotei is a stratovolcano—a symmetrical cone composed of alternating layers of hardened lava, solidified ash, and volcanic rocks ejected in previous eruptions. It reaches a height of 1,898 meters (6,227 feet), and its summit sports a 700-meter- (2,297-foot-) wide crater. Snow often caps this volcano, but in this summertime shot, the volcano's summit is snow-free. The volcano is also known as Ezo-Fuji for its resemblance to Mount Fuji. As angular patches of gray and beige indicate, urban areas surround the volcano, most notably the city of Kutchan to the northwest. Even when volcanoes remain active, people often settle close to them, drawn by benefits [ http://earthobservatory.nasa.gov/Study/NatHazards/ ] of good soil and mild climates that appear to outweigh the risks. NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
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Dust Storm in Southern Calif
…
| Title |
Dust Storm in Southern California |
| Description |
Along historic Route 66, [ http://www.historic66.com/ ] just southeast of the little town of Amboy, California, lies a dried-up lake. Dry lakebeds are good sources of two things: salt and dust. In this image, the now-parched Bristol Lake offers up both. On April 12, 2007, dust storms menaced the area around Amboy. To the northwest, near Newberry Springs, California, dust hampered visibility and led to a multi-car collision on Interstate 40, killing two people and injuring several others. The same day, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite captured this image of a dust storm in the dry remains of Bristol Lake. Many small dust clouds boil up from the ground surface, casting their shadows to the northwest. A bright white cloud floating over the dust also throws its shadow onto the ground below. East of the dust storm are salt works that stand out from the surrounding landscape thanks to their straight lines and sharp angles. Dark ground surfaces alternate with mined white salt in a network of stripes. When lakes evaporate, chemicals that had been dissolved in the water stay behind, making dry lake beds an ideal place to find heavy concentrations of minerals, including salt. Besides the salt works, something else appears in stark contrast to this arid place. Lush green fields of irrigated crops appear in the east. Besides their color, their orderly arrangement reveals their human-made origin. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Dust Storm in Southern Calif
…
| Title |
Dust Storm in Southern California |
| Description |
Along historic Route 66, [ http://www.historic66.com/ ] just southeast of the little town of Amboy, California, lies a dried-up lake. Dry lakebeds are good sources of two things: salt and dust. In this image, the now-parched Bristol Lake offers up both. On April 12, 2007, dust storms menaced the area around Amboy. To the northwest, near Newberry Springs, California, dust hampered visibility and led to a multi-car collision on Interstate 40, killing two people and injuring several others. The same day, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite captured this image of a dust storm in the dry remains of Bristol Lake. Many small dust clouds boil up from the ground surface, casting their shadows to the northwest. A bright white cloud floating over the dust also throws its shadow onto the ground below. East of the dust storm are salt works that stand out from the surrounding landscape thanks to their straight lines and sharp angles. Dark ground surfaces alternate with mined white salt in a network of stripes. When lakes evaporate, chemicals that had been dissolved in the water stay behind, making dry lake beds an ideal place to find heavy concentrations of minerals, including salt. Besides the salt works, something else appears in stark contrast to this arid place. Lush green fields of irrigated crops appear in the east. Besides their color, their orderly arrangement reveals their human-made origin. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Ivan
| Title |
Hurricane Ivan |
| Description |
Interstate 10 is a heavily traveled roadway connecting Florida?s panhandle to the west. The road stretches from the eastern shore of northern Florida to Los Angeles, California, skirting the Gulf shore to Houston, then following the Mexican border to California. Just before leaving Florida, a traveler on I-10 would cross Escambia Bay near Pensacola. That was before Hurricane Ivan blasted through the Florida panhandle. The storm?s fierce 130-mile-per-hour winds and possibly its storm surge cut through the bridge, leaving a wide gap in Interstate 10. The gap is visible in this image, acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) aboard NASA?s Terra [ http://terra.nasa.gov/ ] satellite on September 21, 2004, five days after Ivan made landfall. The road forms a thin white line across the dark waters of Escambia Bay in a comparison image, taken on September 28, 2003. In the 2004 image, the line is broken. Further evidence of Ivan's fury is visible in the top image. Large tracts of darker red regions along the Escambia River, left, and the Yellow River, right, are probably flooded. This pair of false-color composite images was made by combining the near infrared, red, and green wavelengths (ASTER bands 3, 2, & 1), making vegetation appear red and water look black. NASA image created by Jesse Allen, Earth Observatory from data provided by Michael Abrams and the MITI, ERSDAC, JAROS, and the U.S./Japan ASTER [ http://asterweb.jpl.nasa.gov/ ] Science Team. |
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Hurricane Ivan
| Title |
Hurricane Ivan |
| Description |
Interstate 10 is a heavily traveled roadway connecting Florida?s panhandle to the west. The road stretches from the eastern shore of northern Florida to Los Angeles, California, skirting the Gulf shore to Houston, then following the Mexican border to California. Just before leaving Florida, a traveler on I-10 would cross Escambia Bay near Pensacola. That was before Hurricane Ivan blasted through the Florida panhandle. The storm?s fierce 130-mile-per-hour winds and possibly its storm surge cut through the bridge, leaving a wide gap in Interstate 10. The gap is visible in this image, acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) aboard NASA?s Terra [ http://terra.nasa.gov/ ] satellite on September 21, 2004, five days after Ivan made landfall. The road forms a thin white line across the dark waters of Escambia Bay in a comparison image, taken on September 28, 2003. In the 2004 image, the line is broken. Further evidence of Ivan's fury is visible in the top image. Large tracts of darker red regions along the Escambia River, left, and the Yellow River, right, are probably flooded. This pair of false-color composite images was made by combining the near infrared, red, and green wavelengths (ASTER bands 3, 2, & 1), making vegetation appear red and water look black. NASA image created by Jesse Allen, Earth Observatory from data provided by Michael Abrams and the MITI, ERSDAC, JAROS, and the U.S./Japan ASTER [ http://asterweb.jpl.nasa.gov/ ] Science Team. |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Timbalier Island and its northeastern companions are visible in this pair of infrared-enhanced images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. Timbalier Island, the largest island pictured here, sits at the interface between the Gulf of Mexico (south) and Terrebonne Bay (north) along the Louisiana coast southwest of New Orleans. Compared to the image from 2000 (bottom), a large swath of bright sand dominates the eastern side of Timbalier Island in the September 13 image, having either been piled there or exposed by waves and storm surge. To the east-northeast, two small, curving islands have disappeared completely, while farther north, the fierce seas turned two small slots in a barrier island into a single large gap. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Timbalier Island and its northeastern companions are visible in this pair of infrared-enhanced images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. Timbalier Island, the largest island pictured here, sits at the interface between the Gulf of Mexico (south) and Terrebonne Bay (north) along the Louisiana coast southwest of New Orleans. Compared to the image from 2000 (bottom), a large swath of bright sand dominates the eastern side of Timbalier Island in the September 13 image, having either been piled there or exposed by waves and storm surge. To the east-northeast, two small, curving islands have disappeared completely, while farther north, the fierce seas turned two small slots in a barrier island into a single large gap. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Horn and Petit Bois Islands south of Pascagoula, Mississippi, are visible in these infrared-enhanced images captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. The eastern and western tips of Horn island have been eroded so greatly that they are now below sea level, their white sandy beaches (August 7 image) now covered by blue water (September 17 image). The sound (northern) side of the island is layered with sand, which stands out in grayish-white against the red of vegetation. On Petit Bois Island, the changes appear more subtle, but there, too, the red of the island's vegetation appears softened by bright sand. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Gulf Coast cities weren't the only land surfaces to take a beating from Hurricane Katrina in August 2005. Barrier islands stretching from Texas to Florida were also scoured by the wind and waves of the powerful storm. Permanent changes to the shape and elevation of Horn and Petit Bois Islands south of Pascagoula, Mississippi, are visible in these infrared-enhanced images captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite. The eastern and western tips of Horn island have been eroded so greatly that they are now below sea level, their white sandy beaches (August 7 image) now covered by blue water (September 17 image). The sound (northern) side of the island is layered with sand, which stands out in grayish-white against the red of vegetation. On Petit Bois Island, the changes appear more subtle, but there, too, the red of the island's vegetation appears softened by bright sand. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
A fringe of barrier islands line the coast of Mississippi, protecting the mainland from the pounding waves of most ocean storms, but the islands could not shelter the mainland from Hurricane Katrina's exceptionally powerful storm surge. The battering waves ate away at the islands, permanently altering their shape. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of East and West Ship Islands and Cat Island on September 8, 2005. The lower image is made up of two difference ASTER scenes. The scene on the left was acquired on June 4, 2005, while the scene on the right was taken on April 22, 2001. A diagonal line where the ocean changes color indicates the division between the two images. The most dramatic change can be seen in East Ship Island. Compared to April 2001, most of East Ship Island has disappeared beneath the ocean by September 8, 2005. Some of the erosion may have occurred in other storms between 2001 and 2005, but Katrina is probably responsible for much of the damage. The ghost shores of the island are faintly visible under the water as a lighter shade of blue. West Ship Island, which hosts a civil war fort and a historic lighthouse, and Cat Island have also shrunk slightly. The southern tip of Cat Island is missing and the pointed tips of Ship Island have been rounded out. The section of the northwestern shore that holds the lighthouse and fort seems to be unchanged. East and West Ship Islands are no strangers to the type of erosion Katrina inflicted on them. The islands had been a single island until Hurricane Camille cleft it in two in 1969. In general, barrier islands are constantly changing, their shorelines building and eroding at remarkable speed, with dramatic change occurring routinely when powerful storms strike. In competition with nature, humans also have a large impact on barrier islands. Such islands are popular vacation spots. Construction can interfere with beach building and can degrade the vegetation that anchors dunes on the islands. Of the barrier islands along the U.S. coast, East Ship Island is one of the few that remains in its natural state, unchanged by population. To preserve the islands, Congress added them to Gulf Islands National Seashore [ http://www.nps.gov/guis/extended/MIS/MNature/Islands.htm ], the United States' largest national seashore, under the National Park Service. Cat Island forms the western boundary of the park, which consists of a string of islands along the Mississippi and Florida coasts, including East and West Ship Island. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
A fringe of barrier islands line the coast of Mississippi, protecting the mainland from the pounding waves of most ocean storms, but the islands could not shelter the mainland from Hurricane Katrina's exceptionally powerful storm surge. The battering waves ate away at the islands, permanently altering their shape. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of East and West Ship Islands and Cat Island on September 8, 2005. The lower image is made up of two difference ASTER scenes. The scene on the left was acquired on June 4, 2005, while the scene on the right was taken on April 22, 2001. A diagonal line where the ocean changes color indicates the division between the two images. The most dramatic change can be seen in East Ship Island. Compared to April 2001, most of East Ship Island has disappeared beneath the ocean by September 8, 2005. Some of the erosion may have occurred in other storms between 2001 and 2005, but Katrina is probably responsible for much of the damage. The ghost shores of the island are faintly visible under the water as a lighter shade of blue. West Ship Island, which hosts a civil war fort and a historic lighthouse, and Cat Island have also shrunk slightly. The southern tip of Cat Island is missing and the pointed tips of Ship Island have been rounded out. The section of the northwestern shore that holds the lighthouse and fort seems to be unchanged. East and West Ship Islands are no strangers to the type of erosion Katrina inflicted on them. The islands had been a single island until Hurricane Camille cleft it in two in 1969. In general, barrier islands are constantly changing, their shorelines building and eroding at remarkable speed, with dramatic change occurring routinely when powerful storms strike. In competition with nature, humans also have a large impact on barrier islands. Such islands are popular vacation spots. Construction can interfere with beach building and can degrade the vegetation that anchors dunes on the islands. Of the barrier islands along the U.S. coast, East Ship Island is one of the few that remains in its natural state, unchanged by population. To preserve the islands, Congress added them to Gulf Islands National Seashore [ http://www.nps.gov/guis/extended/MIS/MNature/Islands.htm ], the United States' largest national seashore, under the National Park Service. Cat Island forms the western boundary of the park, which consists of a string of islands along the Mississippi and Florida coasts, including East and West Ship Island. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
|
Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
A fringe of barrier islands line the coast of Mississippi, protecting the mainland from the pounding waves of most ocean storms, but the islands could not shelter the mainland from Hurricane Katrina's exceptionally powerful storm surge. The battering waves ate away at the islands, permanently altering their shape. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of East and West Ship Islands and Cat Island on September 8, 2005. The lower image is made up of two difference ASTER scenes. The scene on the left was acquired on June 4, 2005, while the scene on the right was taken on April 22, 2001. A diagonal line where the ocean changes color indicates the division between the two images. The most dramatic change can be seen in East Ship Island. Compared to April 2001, most of East Ship Island has disappeared beneath the ocean by September 8, 2005. Some of the erosion may have occurred in other storms between 2001 and 2005, but Katrina is probably responsible for much of the damage. The ghost shores of the island are faintly visible under the water as a lighter shade of blue. West Ship Island, which hosts a civil war fort and a historic lighthouse, and Cat Island have also shrunk slightly. The southern tip of Cat Island is missing and the pointed tips of Ship Island have been rounded out. The section of the northwestern shore that holds the lighthouse and fort seems to be unchanged. East and West Ship Islands are no strangers to the type of erosion Katrina inflicted on them. The islands had been a single island until Hurricane Camille cleft it in two in 1969. In general, barrier islands are constantly changing, their shorelines building and eroding at remarkable speed, with dramatic change occurring routinely when powerful storms strike. In competition with nature, humans also have a large impact on barrier islands. Such islands are popular vacation spots. Construction can interfere with beach building and can degrade the vegetation that anchors dunes on the islands. Of the barrier islands along the U.S. coast, East Ship Island is one of the few that remains in its natural state, unchanged by population. To preserve the islands, Congress added them to Gulf Islands National Seashore [ http://www.nps.gov/guis/extended/MIS/MNature/Islands.htm ], the United States' largest national seashore, under the National Park Service. Cat Island forms the western boundary of the park, which consists of a string of islands along the Mississippi and Florida coasts, including East and West Ship Island. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Dauphin Island guards the mouth of Mobile Bay, Alabama, from the open waters of the Gulf of Mexico. Though not directly under the eye of the storm, the island was blasted with a powerful storm surge when Hurricane Katrina came ashore on August 29, 2005. When the storm passed, Dauphin Island had been divided in two. On September 10, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the permanently altered island. A large inlet has been cut across the island in the same spot that a much smaller inlet existed before the storm. The western tip of the island has also been washed away, though no other changes are obvious. Miraculously, the thin causeway that connects the island to the mainland appears to be intact. In these images, vegetation is red while sand is a brilliant white. Barrier islands are constantly changing with shorelines building and eroding at remarkable speed. The islands are also routinely shaped by powerful storms, sometimes dramatically breaking apart as Dauphin Island broke under Katrina's wrath. Barrier islands often absorb the brunt of a hurricane's storm surge, offering some protection to the mainland shore. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Katrina Erodes the
…
| Title |
Hurricane Katrina Erodes the U.S. Gulf Coast |
| Description |
Dauphin Island guards the mouth of Mobile Bay, Alabama, from the open waters of the Gulf of Mexico. Though not directly under the eye of the storm, the island was blasted with a powerful storm surge when Hurricane Katrina came ashore on August 29, 2005. When the storm passed, Dauphin Island had been divided in two. On September 10, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) captured the top image of the permanently altered island. A large inlet has been cut across the island in the same spot that a much smaller inlet existed before the storm. The western tip of the island has also been washed away, though no other changes are obvious. Miraculously, the thin causeway that connects the island to the mainland appears to be intact. In these images, vegetation is red while sand is a brilliant white. Barrier islands are constantly changing with shorelines building and eroding at remarkable speed. The islands are also routinely shaped by powerful storms, sometimes dramatically breaking apart as Dauphin Island broke under Katrina's wrath. Barrier islands often absorb the brunt of a hurricane's storm surge, offering some protection to the mainland shore. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Rita Floods U.S. G
…
| Title |
Hurricane Rita Floods U.S. Gulf Coast |
| Description |
The Neches River flows 670 kilometers (416 miles) through Texas before pouring into Sabine Lake and then the Gulf of Mexico. In its final few kilometers, the river passes through Beaumont, Texas, one of the largest oil refining regions in East Texas. The river is an important conduit from the oil refineries to the Gulf of Mexico and the world. Beaumont and the Neches River were also almost directly in Hurricane Rita's path when it came ashore on September 24, 2005. There are some obvious signs of damage in the top image, collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on September 27, 2005. Several permanent structures had been built in the bulge in the river shown here. The structures, probably related to the region's oil industry, were tossed in Rita's strong winds, heavy rains, and battering waves. Their positions have shifted compared to their locations on April 18, 2001, lower image. Some of the structures are clearly broken, with sections missing. Along the shore, dark flood water surrounds a series of circular buildings. These ASTER images are shown in false color. Vegetation is red, and water is dark blue. The large images extend from Beaumont in the north to the Gulf of Mexico. Additional flooding is evident near the Gulf in the large images. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Hurricane Rita Floods U.S. G
…
| Title |
Hurricane Rita Floods U.S. Gulf Coast |
| Description |
The Neches River flows 670 kilometers (416 miles) through Texas before pouring into Sabine Lake and then the Gulf of Mexico. In its final few kilometers, the river passes through Beaumont, Texas, one of the largest oil refining regions in East Texas. The river is an important conduit from the oil refineries to the Gulf of Mexico and the world. Beaumont and the Neches River were also almost directly in Hurricane Rita's path when it came ashore on September 24, 2005. There are some obvious signs of damage in the top image, collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on September 27, 2005. Several permanent structures had been built in the bulge in the river shown here. The structures, probably related to the region's oil industry, were tossed in Rita's strong winds, heavy rains, and battering waves. Their positions have shifted compared to their locations on April 18, 2001, lower image. Some of the structures are clearly broken, with sections missing. Along the shore, dark flood water surrounds a series of circular buildings. These ASTER images are shown in false color. Vegetation is red, and water is dark blue. The large images extend from Beaumont in the north to the Gulf of Mexico. Additional flooding is evident near the Gulf in the large images. NASA images courtesy Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ] |
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Earthquake in Chile
| Title |
Earthquake in Chile |
| Description |
At 12:40 pm local time, a powerful earthquake hit northern Chile. The 7.7-magnitude event was centered in a remote area of the country, 170 kilometers (105 miles) north of the port city of Antofagasta, and well inland from the coast. According to the United States Geological Survey, [ http://www.usgs.gov/ ] the epicenter was located at a depth of 50 kilometers (37 miles) underground. The substantial depth meant that the powerful quake did not cause the severe damage a shallower event of similar strength would have caused. However, news reports indicated that power lines were knocked down, and many buildings collapsed across a wide area, leaving as many as 15,000 homeless. The quake also produced major cracks in the runways at the Antofagasta airport. In the immediate hours after the major event, the USGS also recorded a series of smaller aftershocks, with magnitudes ranging from 4.9 to 5.7. (The magnitude scale measurement for earthquakes is logarithmic, such that a 5.7-magnitude event is 100 times less powerful than a 7.7-magnitude event.) This visualization shows the landscape around the epicenter of the earthquake. The elevation data was recorded by the ASTER [ http://asterweb.jpl.nasa.gov/ ] instrument on NASA's Terra [ http://terra.nasa.gov/ ] satellite. This region of Chile has steep coastal cliffs, a high coastal plain, and further inland, the ridgelines of the Andes Mountains. All these are formed through the interaction of many different geological processes, but the dominant force at work in shaping and reshaping Chile's coast and mountain ranges is plate tectonics. Along the edge of the continent, two blocks of the Earth's crust meet. The Nazca plate under the ocean is heavier than the South American plate, which houses the continent. The Nazca plate slides eastward beneath the South America plate, forcing the lighter plate upwards. This subduction process is slow and steady in some locations, but gets stuck in others. Stress builds up where the two plates are locked together until the rock reaches a breaking point. The fracture causes a sudden shift that sends shockwaves through the surrounding rock: an earthquake. In Chile, large earthquakes through recent history occur roughly every 25 to 100 years apart. The strongest earthquake ever recorded by modern instruments was a 9.5-magnitude quake on May 22, 1960, which was centered offshore in southern Chile, where it set off a huge tsunami. Other large quakes in Chile were recorded on March 3, 1985 (magnitude 7.8 offshore of central Chile) and July 30, 1995 (magnitude 8.1 in Antofagasta, Northern Chile). The depth of the recent event and its distance in from the shoreline meant that although tsunami warnings were issued, no serious tsunami event was recorded. NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. [ http://asterweb.jpl.nasa.gov/ ] |
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