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Browse All : Images of Washington, D.C. from February 11, 2000 and February 2000

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Tsunami Inundation, North of …
PIA06671
Sol (our sun)
ASTER, SIR-C/X-SAR
Title Tsunami Inundation, North of Phuket, Thailand ASTER Images and SRTM Elevation Model
Original Caption Released with Image Figure 1 The Indian Ocean coastline north of Phuket, Thailand is a major tourist destination that was in the path of the tsunami produced by a giant offshore earthquake on December 26, 2004. This disaster resulted in a heavy loss of life. These simulated natural color ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) images show a 27 kilometer (17-mile) long stretch of coast 80 kilometers (50 miles) north of the Phuket airport in the Khao Lak area on December 31 (middle) and also two years earlier (left). The changes along the coast are obvious (changing from green to grey) where the vegetation was stripped away by the tsunami. The image on the right is a copy of the later ASTER scene but it includes highlighting in red for areas that have elevations within 10 meters (33 feet) of sea level. This elevation information was supplied by the Shuttle Radar Topography Mission (SRTM). The red areas appear to include most of the tsunami inundated areas. The geographic correspondence of the imaged damage and the highlighted elevation range is quite good in the middle and upper parts of the scene and is consistent with an early field report of about 10 meters of inundation. In the south, the elevation range corresponds to a much wider area than the actual damage, but this is to be expected for areas increasingly far from the coast. Offshore bathymetry (depth variations), coastal landforms, distance from the coast, and additional factors other than elevation range control the damage extent. But elevation measurements along the coast, as provided by SRTM, give a general indication of areas at risk, as now confirmed by ASTER. ASTER images Earth to map and monitor the changing surface of our planet 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). These data provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. ASTER is one of five Earth-observing instruments launched December 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. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour,, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C. Size: 9.75 x 27.6 kilometers (6.0 x 17.1 miles), Location: 8.6 degrees North latitude, 98.3 degrees East longitude Orientation: Top is 8.25 degrees east of North Image Data: ASTER Bands 1, 2, 3 mixed for simulated true color. Date Acquired: November 15, 2002 and December 31, 2004 (ASTER), February 2000 (SRTM)
Tsunami Inundation, North of …
PIA06671
Sol (our sun)
ASTER, SIR-C/X-SAR
Title Tsunami Inundation, North of Phuket, Thailand ASTER Images and SRTM Elevation Model
Original Caption Released with Image Figure 1 The Indian Ocean coastline north of Phuket, Thailand is a major tourist destination that was in the path of the tsunami produced by a giant offshore earthquake on December 26, 2004. This disaster resulted in a heavy loss of life. These simulated natural color ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) images show a 27 kilometer (17-mile) long stretch of coast 80 kilometers (50 miles) north of the Phuket airport in the Khao Lak area on December 31 (middle) and also two years earlier (left). The changes along the coast are obvious (changing from green to grey) where the vegetation was stripped away by the tsunami. The image on the right is a copy of the later ASTER scene but it includes highlighting in red for areas that have elevations within 10 meters (33 feet) of sea level. This elevation information was supplied by the Shuttle Radar Topography Mission (SRTM). The red areas appear to include most of the tsunami inundated areas. The geographic correspondence of the imaged damage and the highlighted elevation range is quite good in the middle and upper parts of the scene and is consistent with an early field report of about 10 meters of inundation. In the south, the elevation range corresponds to a much wider area than the actual damage, but this is to be expected for areas increasingly far from the coast. Offshore bathymetry (depth variations), coastal landforms, distance from the coast, and additional factors other than elevation range control the damage extent. But elevation measurements along the coast, as provided by SRTM, give a general indication of areas at risk, as now confirmed by ASTER. ASTER images Earth to map and monitor the changing surface of our planet 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). These data provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. ASTER is one of five Earth-observing instruments launched December 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. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour,, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C. Size: 9.75 x 27.6 kilometers (6.0 x 17.1 miles), Location: 8.6 degrees North latitude, 98.3 degrees East longitude Orientation: Top is 8.25 degrees east of North Image Data: ASTER Bands 1, 2, 3 mixed for simulated true color. Date Acquired: November 15, 2002 and December 31, 2004 (ASTER), February 2000 (SRTM)
Nyiragongo volcano, Congo, P …
PIA03338
Sol (our sun)
C-Band Interferometric Radar …
Title Nyiragongo volcano, Congo, Perspective View with Lava SRTM / ASTER / Landsat
Original Caption Released with Image The Nyiragongo volcano in the Congo erupted on January 17, 2002, and subsequently sent streams of lava into the city of Goma on the north shore of Lake Kivu. More than 100 people were killed, more than 12,000 homes were destroyed, and hundreds of thousands were forced to flee the broader community of nearly half a million people. This computer-generated visualization combines a Landsat satellite image and an elevation model from the Shuttle Radar Topography Mission (SRTM) to provide a view of both the volcano and the city of Goma, looking slightly east of north. Additionally, image data from the Advanced Spaceborne Thermal Emission and reflection Radiometer (ASTER) on NASA's Terra satellite were used to supply a partial map of the recent lava flows (red), including a complete mapping of their intrusion into Goma as of January 28, 2002. Lava is also apparent within the volcanic crater and at a few other locations. Thick (but broken) cloud cover during the ASTER image acquisition prevented a complete mapping of the lava distribution, but future image acquisitions should complete the mapping. Nyiragongo is the steep volcano on the right, Lake Kivu is in the foreground, and the city of Goma has a light pink speckled appearance along the shoreline. Nyiragongo peaks at about 3,470 meters (11,380 feet) elevation and reaches almost exactly 2,000 meters (6,560 feet)above Lake Kivu. The shorter but broader Nyamuragira volcano appears in the left background. Topographic expression has been exaggerated vertically by a factor of 1.5 for this visualization. Goma, Lake Kivu, Nyiragongo, Nyamuragira and other nearby volcanoes sit within the East African Rift Valley, a zone where tectonic processes are cracking, stretching, and lowering the Earth's crust. Volcanic activity is common here, and older but geologically recent lava flows (magenta in this depiction) are particularly apparent on the flanks of the Nyamuragira volcano. The Landsat image used here was acquired on December 11, 2001, about a month before the eruption, and shows an unusually cloud-free view of this tropical terrain. Minor clouds and their shadows were digitally removed to clarify the view, topographic shading derived from the SRTM elevation model was added to the Landsat image, and a false sky was added. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. This Landsat 7 Thematic Mapper image was provided to the SRTM and ASTER projects by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, S.D. 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), the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) will image Earth, for several years to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 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. ASTER is providing scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission(SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA)of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: View width 21 kilometers (13 miles), View distance 42 kilometers(26 miles) Location: 1.5 degrees South latitude, 29.3 degrees East longitude Orientation: View east-northeast, 5 degrees below horizontal Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively. ASTER Band 12(thermal) shown as red overlay. Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Landsat 30 meters (98 feet). ASTER (thermal) 90 meters (295 feet). Date Acquired: February 2000 (SRTM), December 11, 2001 (Landsat), January 28, 2002(ASTER)
Nyiragongo Volcano, Congo, M …
PIA03339
Sol (our sun)
C-Band Interferometric Radar …
Title Nyiragongo Volcano, Congo, Map View with Lava, Landsat / ASTER / SRTM
Original Caption Released with Image The Nyiragongo volcano in the Congo erupted on January 17, 2002, and subsequently sent streams of lava into the city of Goma on the north shore of Lake Kivu. More than 100 people were killed, more than 12,000 homes were destroyed, and hundreds of thousands were forced to flee the broader community of nearly half a million people. This Landsat satellite image shows the volcano (right of center), the city of Goma, and surrounding terrain. Image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite were used to supply a partial map of the recent lava flows (red overlay), including a complete mapping of their intrusion into Goma as of January 28, 2002. Lava is also apparent within the volcanic crater and at a few other locations. Thick (but broken) cloud cover during the ASTER image acquisition prevented a complete mapping of the lava distribution, but future image acquisitions should complete the mapping. Goma has a light pink speckled appearance along the shore of Lake Kivu. The city airport parallels, and is just right (east) of, the larger lava flow. Nyiragongo peaks at about 3,470 meters (11,380 feet) elevation and reaches almost exactly 2,000 meters (6,560 feet) above Lake Kivu. The shorter but much broader Nyamuragira volcano appears in the upper left. Goma, Lake Kivu, Nyiragongo, Nyamuragira and other nearby volcanoes sit within the East African Rift Valley, a zone where tectonic processes are cracking, stretching, and lowering the Earth's crust. Volcanic activity is common here, and older but geologically recent lava flows (magenta in this depiction) are particularly apparent on the flanks of the Nyamuragira volcano. The Landsat image used here was acquired on December 11, 2001, about a month before the eruption, and shows an unusually cloud-free view of this tropical terrain. Minor clouds and their shadows were digitally removed to clarify the view and topographic shading derived from the SRTM elevation model was added to the Landsat image. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. This Landsat 7 Thematic Mapper image was provided to the SRTM and ASTER projects by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D. 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), the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) will image Earth for several years to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 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. ASTER is providing scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter(approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. Size: 21 by 42 kilometers (13 by 26 miles) Location: 1.5 degrees South latitude, 29.3 degrees East longitude Orientation: East-northeast at top Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively. ASTER Band 12 (thermal) shown as red overlay. Original Data Resolution: Landsat 30 meters (98 feet). ASTER (thermal) 90 meters (295 feet), SRTM 1 arcsecond (30 meters or 98 feet). Date Acquired: December 11, 2001 (Landsat), January 28, 2002 (ASTER), February 2000 (SRTM).
Colored Height and Shaded Re …
PIA03364
Sol (our sun)
C-Band Interferometric Radar
Title Colored Height and Shaded Relief, Central America
Original Caption Released with Image Panama, Costa Rica, Nicaragua, El Salvador, Honduras, Guatemala, Belize, southern Mexico and parts of Cuba and Jamaica are all seen in this image from NASA's Shuttle Radar Topography Mission. The dominant feature of the northern part of Central America is the Sierra Madre Range, spreading east from Mexico between the narrow Pacific coastal plain and the limestone lowland of the Yucatan Peninsula. Parallel hill ranges sweep across Honduras and extend south, past the Caribbean Mosquito Coast to lakes Managua and Nicaragua. The Cordillera Central rises to the south, gradually descending to Lake Gatun and the Isthmus of Panama. A highly active volcanic belt runs along the Pacific seaboard from Mexico to Costa Rica. High-quality satellite imagery of Central America has, until now, been difficult to obtain due to persistent cloud cover in this region of the world. The ability of SRTM to penetrate clouds and make three-dimensional measurements has allowed the generation of the first complete high-resolution topographic map of the entire region. This map was used to generate the image. Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations. For an annotated version of this image, please select Figure 1, below:(Large image: ~9 mB jpeg) Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (200-foot)-long mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 1720 by 1670 kilometers (1068 by 1036 miles) Location: 14.5 degrees North latitude, 85.0 degrees West longitude Orientation: North toward the top Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000
Colored Height and Shaded Re …
PIA03364
Sol (our sun)
C-Band Interferometric Radar
Title Colored Height and Shaded Relief, Central America
Original Caption Released with Image Panama, Costa Rica, Nicaragua, El Salvador, Honduras, Guatemala, Belize, southern Mexico and parts of Cuba and Jamaica are all seen in this image from NASA's Shuttle Radar Topography Mission. The dominant feature of the northern part of Central America is the Sierra Madre Range, spreading east from Mexico between the narrow Pacific coastal plain and the limestone lowland of the Yucatan Peninsula. Parallel hill ranges sweep across Honduras and extend south, past the Caribbean Mosquito Coast to lakes Managua and Nicaragua. The Cordillera Central rises to the south, gradually descending to Lake Gatun and the Isthmus of Panama. A highly active volcanic belt runs along the Pacific seaboard from Mexico to Costa Rica. High-quality satellite imagery of Central America has, until now, been difficult to obtain due to persistent cloud cover in this region of the world. The ability of SRTM to penetrate clouds and make three-dimensional measurements has allowed the generation of the first complete high-resolution topographic map of the entire region. This map was used to generate the image. Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations. For an annotated version of this image, please select Figure 1, below:(Large image: ~9 mB jpeg) Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (200-foot)-long mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 1720 by 1670 kilometers (1068 by 1036 miles) Location: 14.5 degrees North latitude, 85.0 degrees West longitude Orientation: North toward the top Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000
Colored Height and Shaded Re …
PIA03374
Sol (our sun)
C-Band Interferometric Radar
Title Colored Height and Shaded Relief, Kamchatka Peninsula
Original Caption Released with Image Russia's Kamchatka Peninsula, lying between the Sea of Okhotsk to the west and the Bering Sea and Pacific Ocean to the east, is one of the most active volcanic regions along the Pacific Ring of Fire. It covers an area about the size of Colorado but contains more than 100 volcanoes stretching across the 1000-kilometer-long (620-mile-long) land mass. A dozen or more of these have active vents, with the youngest located along the eastern half of the peninsula. This color-coded shaded relief image, generated with data from the Shuttle Radar Topography Mission (SRTM), shows Kamchatka's volcanic nature to dramatic effect. Kliuchevskoi, one of the most active and renowned volcanoes in the world, dominates the main cluster of volcanoes called the Kliuchi group, visible as a circular feature in the center-right of the image. The two other main volcanic ranges lie along northeast-southwest lines, with the older, less active range occupying the center and western half of Kamchatka. The younger, more active belt begins at the southernmost point of the peninsula and continues upward along the Pacific coastline. Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction, so northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and brown to white at the highest elevations. The Shuttle Radar Topography Mission flew aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (200-foot)-long mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 1,113 by 638 kilometers (692 by 396 miles) Location: 55 degrees North latitude, 160 degrees East longitude Orientation: North toward the top Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000
Stereo Pair, with Topographi …
PIA03384
Sol (our sun)
C-Band Interferometric Radar
Title Stereo Pair, with Topographic Height as Color, Manicouagan Crater, Quebec, Canada
Original Caption Released with Image Manicouagan Crater is one of the world's largest and oldest known impact craters and perhaps the one most readily apparent to astronauts in orbit. The age of the impact is estimated at 214 million years before present. Since then erosion has removed about one kilometer (0.6 miles) of rock from the region and has created a topographic pattern that follows the structural pattern of the crater. A ring depression (prominently seen as green) encloses a central peak. The ring depression now hosts the Manicouagan Reservoir and so appears as a distinct ring lake to astronauts and as a smooth and flat feature in this topographic visualization. A fine pattern of topographic striations trending south-southeast, most prominent within the crater itself, indicates the flow direction of glaciers that covered this area during the last ice age. Three visualization methods were combined to produce this image: shading, color coding, and synthetic stereoscopy. The shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to blue at the highest elevations. The stereoscopic effect was then created by generating two differing perspectives, one for each eye. The image can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing) or by downloading, printing, and splitting the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of Earth's surface in its full three dimensions. Total topographic relief from the ring lake level to the central crater peak is about 600 meters (2000 feet). Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 222 by 138 kilometers (138 by 87 miles) Location: 50 to 52 degrees North latitude, 68 to 70 degrees West longitude Orientation: North toward the top Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000
Anaglyph with Landsat Virgin …
PIA03392
Sol (our sun)
C-Band Interferometric Radar
Title Anaglyph with Landsat Virgin Islands, Caribbean
Original Caption Released with Image St. Thomas, St. John, Tortola, and Virgin Gorda are the four main islands (lower left to upper right) of this map-view anaglyph of the U.S. Virgin Islands and British Virgin Islands, along the northeast perimeter of the Caribbean Sea. For this view, a nearly cloud-free Landsat image was draped over elevation data from the Shuttle Radar Topography Mission (SRTM), and shading derived from the SRTM data was added to enhance the topographic expression. Coral reefs fringe the islands in many locations and appear as bright patterns in near-shore waters. Tropical vegetation appears fairly dark with smooth tones, as compared to the brighter speckled patterns of towns and other developments. As in much of the world, topography is the primary factor in the pattern of land use development in the Virgin Islands. Topography across most of the islands is quite rugged, and although the steep slopes create a scenic setting, they crowd most development into the small areas of low relief terrain, generally along the shoreline. The topographic pattern also affects water supply, wastewater disposal, landfill locations, road construction, and most other features of the development infrastructure. Topography also defines the natural drainage pattern, which is the major consideration in anticipating tropical storm water runoff dangers, as well as the dangers of heightened sediment impacts upon the adjacent coral reefs. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 79.9 by 48.6 kilometers (49.9 by 30.1 miles) Location: 18.25 degrees North latitude, 64.75 degrees West longitude Orientation: North-Northeast toward the top Image Data: Landsat Band 1 with SRTM shading Original Data Resolution: SRTM and Landsat 30 meters (99 feet) Date Acquired: February 2000 (SRTM), January 21, 1985 (Landsat)
Perspective View with Color- …
PIA03368
Sol (our sun)
C-Band Interferometric Radar
Title Perspective View with Color-Coded Shaded Relief, Panama Canal
Original Caption Released with Image This perspective view shows the Panama Canal with the Gulf of Panama in the foreground and the Caribbean Sea in the distance. The canal runs northwest-southeast from the city of Colon on the Atlantic side to Panama City on the Pacific side. Water levels are maintained along its length by three reservoirs, the largest of which is Lake Gatun, visible at the right center of the image. Built by the U.S. Army Corps of Engineers between 1904 and 1914, the canal extends for approximately 50 miles, and is widely considered to be one of the world's great engineering achievements. This shaded relief perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM). A computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. On flatter surfaces, the pattern of light and shadows can reveal subtle features in the terrain. Colors show the elevation as measured by SRTM, and range from green at the lowest elevations to white at the highest elevations. SRTM, launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: scale varies in this perspective image Location: 9.0 degrees North latitude, 79.8 degrees West longitude Orientation: looking West Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)
Perspective View with Landsa …
PIA03365
Sol (our sun)
C-Band Interferometric Radar …
Title Perspective View with Landsat Overlay, Lakes Managua and Nicaragua
Original Caption Released with Image This perspective view shows Lakes Managua and Nicaragua near the Pacific coast of Nicaragua. Lake Managua is the 65-kilometer (40-mile)-long fresh water lake in the foreground of this south-looking view, emptying via the Tipitapa River into the much larger Lake Nicaragua in the distance. The capital city of Managua, with a population of more than 500,000, is located along the southern shore of Lake Managua, the area with the highest population density in Nicaragua. The physical setting of Lake Managua is dominated by the numerous volcanic features aligned in a northwest-southeast axis. The cone-like feature in the foreground is Momotombo, a 1,280-meter (4,199-foot)-high stratovolcano located on the northwest end of the lake. Two water-filled volcanic craters (Apoyegue and Jiloa volcanoes) reside on the Chiltepe Peninsula protruding into the lake from the west. Two volcanoes can also be seen on the island of Ometepe in Lake Nicaragua: El Maderas rising to 1,394 meters (4,573 feet) and the active El Conception at 1,610 meters (5,282 feet). This three-dimensional perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated two times. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D. Elevation data used in this image was acquired by the SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: scale varies in this perspective image Location: 12.1 degrees North latitude, 86.1degrees West longitude Orientation: looking South Image Data: Landsat bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)
Perspective View with Color- …
PIA03369
Sol (our sun)
C-Band Interferometric Radar
Title Perspective View with Color-Coded Shaded Relief, Central Panama
Original Caption Released with Image This perspective view shows central Panama, with the remnants of the extinct volcano El Valle in the foreground and the Caribbean Sea in the distance. El Valle underwent an explosive eruption about 3 million years ago, forming a crater 5 kilometers (3.1 miles) across, one of the largest in the Americas. The crater subsequently filled with water forming a huge lake, but about 12,000 years ago a breach at the present site of the waterfall Choro de las Mozas caused it to drain, forming the present valley. Within the crater is the town of El Valle de Anton, whose 600-meter (1,968-foot) elevation and resulting cooler climate make it a popular tourist and vacation site. The lake in the distance is Lake Gatun, at the west end of the Panama Canal. The canal itself extends to the southwest (to the right in this northeast facing view) but is hidden by the intervening terrain. This shaded relief perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM). A computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. On flatter surfaces, the pattern of light and shadows can reveal subtle features in the terrain. Colors show the elevation as measured by SRTM, and range from green at the lowest elevations to white at the highest elevations. SRTM, launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: scale varies in this perspective image Location: 8.8 degrees North latitude, 80.0 degrees West longitude Orientation: looking Northeast Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)
Perspective View with Landsa …
PIA03366
Sol (our sun)
C-Band Interferometric Radar …
Title Perspective View with Landsat Overlay, Costa Rica
Original Caption Released with Image This perspective view shows the Caribbean coastal plain of Costa Rica, with the Cordillera Central rising in the background and the Pacific Ocean in the distance. The prominent river in the center of the image is the Rio Sucio, which merges with the Rio Sarapiqui at the bottom of the image and eventually joins with Rio San Juan on the Nicaragua border. Like much of Central America, Costa Rica is generally cloud covered so very little satellite imagery is available. The ability of the Shuttle Radar Topography Mission (SRTM) instrument to penetrate clouds and make three-dimensional measurements will allow generation of the first complete high-resolution topographic map of the entire region. These data were used to generate the image. This three-dimensional perspective view was generated using elevation data from SRTM and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated two times. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D. Elevation data used in this image was acquired by the SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: scale varies in this perspective image Location: 10.4 degrees North latitude, 84.0 degrees West longitude Orientation: looking Southwest Image Data: Landsat Bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)
Anaglyph, Manicouagan Crater …
PIA03385
Sol (our sun)
C-Band Interferometric Radar
Title Anaglyph, Manicouagan Crater, Quebec, Canada
Original Caption Released with Image Manicouagan Crater is one of the world's largest and oldest known impact craters and perhaps the one most readily apparent to astronauts in orbit. The age of the impact is estimated at 214 million years before present. Since then erosion has removed about one kilometer (0.6 miles) of rock from the region and has created a topographic pattern that follows the structural pattern of the crater. A ring depression (prominently seen as dark gray) encloses a central peak. The ring depression now hosts the Manicouagan Reservoir and so appears as a distinct ring lake to astronauts and as a smooth and flat feature in this topographic visualization. A fine pattern of topographic striations trending south-southeast, most prominent within the crater itself, indicates the flow direction of glaciers that covered this area during the last ice age. This anaglyph is derived entirely from the SRTM elevation model. First a gray image was created that uses image brightness to represent a mix of topographic height (higher elevations are brighter) and topographic orientation (northern slopes are brighter). The stereoscopic effect was then created by generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Total topographic relief from the ring lake level to the central crater peak is about 600 meters (2000 feet). Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 222 by 138 kilometers (138 by 87 miles) Location: 50 to 52 degrees North latitude, 68 to 70 degrees West longitude Orientation: North toward the top Image Data: SRTM elevation model as brightness and shading Date Acquired: February 2000
SRTM Perspective with Landsa …
PIA03391
Sol (our sun)
C-Band Interferometric Radar
Title SRTM Perspective with Landsat Virgin Islands, Carribean
Original Caption Released with Image St. Thomas, St. John, Tortola, and Virgin Gorda are the four main islands (front to back) of this east-looking view of the U.S. Virgin Islands and British Virgin Islands, along the northeast perimeter of the Caribbean Sea. For this view, a nearly cloud-free Landsat image was draped over elevation data from the Shuttle Radar Topography Mission (SRTM), and shading derived from the SRTM data was added to enhance the topographic expression. Elevation is shown with 1.5x scaled vertical exaggeration. Coral reefs fringe the islands in many locations and appear as very light shades of blue. Tropical vegetation appears green, and developed areas appear in shades of brown and white. As in much of the world, topography is the primary factor in the pattern of land use development in the Virgin Islands. Topography across most of the islands is quite rugged, and although the steep slopes create a scenic setting, they crowd most development into the small areas of low relief terrain, generally along the shoreline. The topographic pattern also affects water supply, wastewater disposal, landfill locations, road construction, and most other features of the development infrastructure. Topography also defines the natural drainage pattern, which is the major consideration in anticipating tropical storm water runoff dangers, as well as the dangers of heightened sediment impacts upon the adjacent coral reefs. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 94.7 kilometers (58.7 miles) view distance, 29.2 kilometers (18.1 miles) view width Location: 18.25 degrees North latitude, 64.75 degrees West longitude Orientation: Looking EasT Image Data: Landsat Bands 1,2+4, 3 as blue, green, red, respectively Original Data Resolution: SRTM and Landsat 30 meters (99 feet) Date Acquired: February 2000 (SRTM), January 21, 1985 (Landsat)
Perspective View with Landsa …
PIA03367
Sol (our sun)
C-Band Interferometric Radar …
Title Perspective View with Landsat Overlay, San Jose, Costa Rica
Original Caption Released with Image This perspective view shows the capital city of San Jose, Costa Rica, the gray area in the center of the image. The view is toward the northwest with the Pacific Ocean in the distance and shows a portion of the Meseta Central (Central Valley), home to about a third of Costa Rica's population. Like much of Central America, Costa Rica is generally cloud covered, so very little satellite imagery is available. The ability of the Shuttle Radar Topography Mission (SRTM) instrument to penetrate clouds and make three-dimensional measurements will allow generation of the first complete high-resolution topographic map of the entire region. These data were used to generate the image. This three-dimensional perspective view was generated using elevation data from SRTM and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated two times. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D. Elevation data used in this image was acquired by the SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: scale varies in this perspective image Location: 10.0 degrees North latitude, 83.8 degrees West longitude Orientation: looking Northwest Image Data: Landsat Bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)
Richat Structure, Mauritania …
PIA04962
Sol (our sun)
C-Band Interferometric Radar …
Title Richat Structure, Mauritania, Anaglyph, Landsat Image over SRTM Elevation
Original Caption Released with Image German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 174.6 kilometers (108.3 miles) by 112.5 kilometers (69.8 miles) Location: 21.4 degrees North latitude, 12.0 degrees West longitude Orientation: North toward the top Image Data: Landsat band 7 Date Acquired: February 2000 (SRTM), January 13, 1987 (Landsat), The prominent circular feature seen here, known as the Richat Structure, in the Sahara desert of Mauritania, is often noted by astronauts because it forms a conspicuous 50-kilometer-wide (30-mile-wide) bull's-eye on the otherwise rather featureless expanse of the desert. Initially mistaken for a possible impact crater, it is now known to be an eroded circular anticline (structural dome) of layered sedimentary rocks. Extensive sand dunes occur in this region and the interaction of bedrock topography, wind, and moving sand is evident in this scene. Note especially how the dune field generally ends abruptly short of the cliffs as wind from the northeast (upper right) apparently funnels around the cliff, sweeping clean areas near the base of the cliff (particularly at the cliff point to the northwest, upper left, of the Richat Structure). Note also the isolated peak within the dune field. That peak captures some sand on its windward side, but mostly deflects the wind and sand around its sides, creating a sand-barren streak that continues far downwind. To the west (left), a north-south trending bedrock ridge breaks up the sand field, and downwind from the ridge, streaks of dunes occur at certain locations. Upon close inspection, these streaks can be seen to be associated with saddles (low points) along the ridge, where sand preferentially passes over the ridge. This again shows how topographic features control the distribution of sand across the terrain. This anaglyph was created by draping a Landsat reflectance infrared image over an SRTM elevation model, and then generating two differing perspectives, one for each eye. When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter For vertical scale, note that the prominent cliffs (image center) are about 300 meters (about 1000 feet) tall, the central rings of the Richat structure are about 80 meters (about 260 feet) tall, and the sand dunes rise about 80 meters (about 260 feet) above the adjacent terrain across the center of the image. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the
Cape Town, South Africa, Ana …
PIA04960
Sol (our sun)
C-Band Interferometric Radar …
Title Cape Town, South Africa, Anaglyph, Landsat Image over SRTM Elevation
Original Caption Released with Image Cape Town and the Cape of Good Hope, South Africa, appear on the left (west) of this anaglyph view generated from a Landsat satellite image and elevation data from the Shuttle Radar Topography Mission (SRTM). The city center is located between Table Bay (upper left) and Table Mountain (just to the south), a 1,086-meter (3,563-foot) tall sandstone and granite natural landmark. Cape Town enjoys a Mediterranean climate but must deal with the limited water supply characteristic of that climate. Until the 1890s the city relied upon streams and springs along the base of Table Mountain, then built a small reservoir atop Table Mountain to capture and store rainfall there (visible in this anaglyph when viewed at full resolution). Now the needs of a much larger population are met in part by much larger reservoirs such as seen well inland (upper right) at the Theewaterskloof Dam. False Bay is the large bay to the southeast (lower right) of Cape Town, just around the Cape of Good Hope. It is one of the largest bays along the entire South African coast, but nearby Cape Town has its harbor at Table Bay. False Bay got its name because mariners approaching Cape Town from the east would see the prominent bay and falsely assume it to be the entrance to Cape Town harbor. Similarly, people often mistake the Cape of Good Hope as the southernmost point of Africa. But the southernmost point is actually Cape Agulhas, located just to the southeast (lower right) of this scene. This anaglyph was created by draping a Landsat visible light image over an SRTM elevation model, and then generating two differing perspectives, one for each eye. When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. View Size: 66 kilometers (41 miles) by 134 kilometers (83 miles) Location: 34.2 degrees South latitude, 18.7 degrees East longitude Orientation:, North-northeast at top Image Data: Landsat Bands 1, 2, 3 merged as grey Date Acquired: February 2000 (SRTM), June 13, 2000 (Landsat)
SRTM Perspective of Colored …
PIA03312
Sol (our sun)
C-Band Interferometric Radar
Title SRTM Perspective of Colored Height and Shaded Relief Laguna Mellquina, Andes Mountains, Argentina
Original Caption Released with Image This depiction of an area south of San Martin de Los Andes, Argentina, is the first Shuttle Radar Topography Mission (SRTM)view of the Andes Mountains, the tallest mountain chain in the western hemisphere. This particular site does not include the higher Andes peaks, but it does include steep-sided valleys and other distinctive landforms carved by Pleistocene glaciers. Elevations here range from about 700 to 2,440 meters (2,300 to 8,000 feet). This region is very active tectonically and volcanically, and the landforms provide a record of the changes that have occurred over many thousands of years. Large lakes fill the broad mountain valleys, and the spectacular scenery here makes this area a popular resort destination for Argentinians. Three visualization methods were combined to produce this image: shading, color coding of topographic height and a perspective view. The shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark, as would be the case at noon at this latitude in the southern hemisphere. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations. The perspective is toward the west, 20 degrees off horizontal with 2X vertical exaggeration. The back (west) edge of the data set forms a false skyline within the Andes Range. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 55.0 x 37.2 kilometers ( 34.1 x 23.1 miles) Location: 40.4 deg. South lat., 71.3 deg. West lon. Orientation: West toward the top Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000
Shaded Relief with Color as …
PIA03333
Sol (our sun)
C-Band Interferometric Radar
Title Shaded Relief with Color as Height, California Mosaic
Original Caption Released with Image The diversity of landforms that make up the state of California is evident in this new rendition of the 3-D topography of the state. The Central Valley, flanked on the east by the Sierra Nevada, dominates the scene with San Francisco and Monterey Bays clearly visible at left center. Other features of interest include Lake Tahoe at the edge to the right of San Francisco, Mono Lake below Lake Tahoe, and the Salton Sea at the lower right. The prominent sideways "V" in the southern part of the state is the intersection of the Garlock and San Andreas Faults - to the east is the Mojave Desert. Offshore are the Channel Islands and to the right of them lies the city of Los Angeles. Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction. North-facing slopes appear bright and south-facing slopes appear dark. Color coding is directly related to topographic height, with blue and green at the lower elevations, rising through yellow and brown to white at the highest elevations. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar(SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot)mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 950 by 1100 kilometers ( 590 by 680 miles) Location: 32.5-42 deg. North lat., 114-125 deg. West lon. Orientation: North toward the top Image Data: Shaded and colored SRTM elevation model Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000
Nyiragongo volcano, Congo, A …
PIA03340
Sol (our sun)
C-Band Interferometric Radar …
Title Nyiragongo volcano, Congo, Anaglyph, SRTM / Landsat
Original Caption Released with Image The Nyiragongo volcano in the Congo erupted on January 17, 2002, and subsequently sent streams of lava into the city of Goma on the north shore of Lake Kivu. More than 100 people were killed, more than 12,000 homes were destroyed, and hundreds of thousands were forced to flee the broader community of nearly half a million people. This stereoscopic (anaglyph)visualization combines a Landsat satellite image and an elevation model from the Shuttle Radar Topography Mission (SRTM) to provide a view of the volcano, the city of Goma, and surrounding terrain. Nyiragongo is the steep volcano to the lower right of center, Lake Kivu is at the bottom, and the city of Goma is located along the northeast shore(bottom center). Nyiragongo peaks at about 3,470 meters (11,380 feet)elevation and reaches almost exactly 2,000 meters (6,560 feet) above Lake Kivu. The shorter but broader Nyamuragira volcano appears to the upper left of Nyiragongo. Goma, Lake Kivu, Nyiragongo, Nyamuragira and other nearby volcanoes sit within the East African Rift Valley, a zone where tectonic processes are cracking, stretching, and lowering the Earth's crust. The cliff at the top center of the image is the western edge of the rift. Volcanic activity is common in the rift, and older but geologically recent lava flows (dark in this depiction) are particularly apparent on the flanks of the Nyamuragira volcano. This anaglyph was produced by first shading an elevation model from data acquired by the Shuttle Radar Topography Mission and blending it with a single band of a Landsat scene. The stereoscopic effect was then created by generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter. The Landsat image used here was acquired on December 11, 2001, about a month before the eruption, and shows an unusually cloud-free view of this tropical terrain. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot)resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. This Landsat 7 Thematic Mapper image was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) DataCenter, Sioux Falls, S.D. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter(approximately 200-foot) mast, installed, additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. Size: 43 by 62 kilometers (27 by 39 miles) Location: 1.5 degrees South latitude, 29.3 degrees East longitude Orientation: East-northeast at top Image Data: Landsat Band 4 (near infrared) combined with SRTM shaded relief Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Landsat 30 meters (98 feet). Date Acquired: February 2000 (SRTM), December 11, 2001 (Landsat).
Cape Town, South Africa, Per …
PIA04961
Sol (our sun)
C-Band Interferometric Radar …
Title Cape Town, South Africa, Perspective View, Landsat Image over SRTM Elevation
Original Caption Released with Image Cape Town and the Cape of Good Hope, South Africa, appear in the foreground of this perspective view generated from a Landsat satellite image and elevation data from the Shuttle Radar Topography Mission (SRTM). The city center is located at Table Bay (at the lower left), adjacent to Table Mountain, a 1,086-meter (3,563-foot) tall sandstone and granite natural landmark. Cape Town enjoys a Mediterranean climate but must deal with the limited water supply characteristic of that climate. Until the 1890s the city relied upon streams and springs along the base of Table Mountain, then built a small reservoir atop Table Mountain to capture and store rainfall there. Now the needs of a much larger population are met in part by much larger reservoirs such as seen here far inland (mid-distance left) at the Theewaterskloof Dam. False Bay is the large bay to the south (right) of Cape Town, just around the Cape of Good Hope. It is one of the largest bays along the entire South African coast, but nearby Cape Town has its harbor at Table Bay. False Bay got its name because mariners approaching Cape Town from the east would see the prominent bay and falsely assume it to be the entrance to Cape Town harbor. Similarly, people often mistake the Cape of Good Hope as the southernmost point of Africa. But the southernmost point is actually Cape Agulhas, located just to the southeast (upper right) of this scene. This Landsat and SRTM perspective view uses a 2-times vertical exaggeration to enhance topographic expression. The back edges of the data sets form a false horizon and a false sky was added. Colors of the scene were enhanced by image processing but are the natural color band combination from the Landsat satellite. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. View Size: 66 kilometers (41 miles) wide by 134 kilometers (83 miles) distance Location: 34.2 degrees South latitude, 18.7 degrees East longitude Orientation: View toward east-southeast Image Data: Landsat Bands 1, 2, 3 in blue, green, red Date Acquired: February 2000 (SRTM), June 13, 2000 (Landsat)
Richat Structure, Mauritania …
PIA04963
Sol (our sun)
C-Band Interferometric Radar …
Title Richat Structure, Mauritania, Perspective View, Landsat Image over SRTM Elevation
Original Caption Released with Image This prominent circular feature, known as the Richat Structure, in the Sahara desert of Mauritania is often noted by astronauts because it forms a conspicuous 50-kilometer-wide (30-mile-wide) bull's-eye on the otherwise rather featureless expanse of the desert. Initially mistaken for a possible impact crater, it is now known to be an eroded circular anticline (structural dome) of layered sedimentary rocks. Extensive sand dunes occur in this region and the interaction of bedrock topography, wind, and moving sand is evident in this scene. Note especially how the dune field ends abruptly short of the cliffs at the far right as wind from the northeast (lower right) apparently funnels around the cliff point, sweeping clean areas near the base of the cliff. Note also the small isolated peak within the dune field. That peak captures some sand on its windward side, but mostly deflects the wind and sand around its sides, creating a sand-barren streak that continues far downwind. This view was generated from a Landsat satellite image draped over an elevation model produced by the Shuttle Radar Topography Mission (SRTM). The view uses a 6-times vertical exaggeration to greatly enhance topographic expression. For vertical scale, note that the height of the mesa ridge in the back center of the view is about 285 meters (about 935 feet) tall. Colors of the scene were enhanced by use of a combination of visible and infrared bands, which helps to differentiate bedrock (browns), sand (yellow, some white), minor vegetation in drainage channels (green), and salty sediments (bluish whites). Some shading of the elevation model was included to further highlight the topographic features. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. View Size: 68 kilometers (42 miles) wide by 112 kilometers (69 miles) distance Location: 21.2 degrees North latitude, 11.7 degrees West longitude Orientation: View toward west-northwest Image Data: Landsat Bands 1, 4, 7 in B.G.R. Date Acquired: February 2000 (SRTM), January 13, 1987 (Landsat)
Zagros Mountains, Iran, SRTM …
PIA04955
Sol (our sun)
C-Band Interferometric Radar …
Title Zagros Mountains, Iran, SRTM Shaded Relief Anaglyph
Original Caption Released with Image Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 98.1 kilometers (60.8 miles) by 148.1 kilometers (91.8 miles) Location: 27.3 degrees North latitude, 54.5 degrees East longitude Orientation: North toward the top Image Data: Shaded SRTM elevation model Date Acquired: February 2000, The Zagros Mountains in Iran offer a visually stunning topographic display of geologic structure in layered sedimentary rocks. This scene is nearly 100 kilometers (62 miles) wide but is only a small part of similar terrain that covers much of southern Iran. This area is actively undergoing crustal shortening, as global tectonics moves Arabia toward Asia. Consequently, layers of sedimentary rock are folding much like a carpet will fold if pushed. The convex upward folds create structures called anticlines, which are prominently seen here. The convex downward folds (between the anticlines) create structures called synclines, which are mostly buried and hidden by sediments eroding off the anticlines. Layers having differing erosional resistance create distinctive patterns, often sawtooth triangular facets, that encircle the anticlines. Local relief between the higher mountain ridges and their intervening valleys is about 1,200 meters (about 4,000 feet). Salt extrusions and salt "glaciers" are another set of geologic features readily evident in the topography. Salt deposits, likely created by the evaporation of an ancient inland sea, were buried by the sediments that now make up the layers of the anticlines and synclines. But salt is less dense than most other rocks, so it tends to migrate upward through Earth's crust in vertical columns called "diapirs". The compressive folding process has probably facilitated the formation of these diapirs, and the diapirs, in turn, are probably enhancing some anticlines by "inflating" them with salt. Where the diapirs reach the surface, the salt extrudes, much like lava from a volcano, and the salt flows. Two prominent salt flows are evident in the same valley, leaking from neighboring anticlines, just north of the scene center. This anaglyph was created by deriving a shaded relief image from the SRTM data, draping it back over the SRTM elevation model, and then generating two differing perspectives, one for each eye. Illumination is from the north (top). When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National
Zagros Mountains, Iran, SRTM …
PIA04956
Sol (our sun)
C-Band Interferometric Radar …
Title Zagros Mountains, Iran, SRTM Shaded Relief
Original Caption Released with Image The Zagros Mountains in Iran offer a visually stunning topographic display of geologic structure in layered sedimentary rocks. This scene is nearly 100 kilometers (62 miles) wide but is only a small part of similar terrain that covers much of southern Iran. This area is actively undergoing crustal shortening, as global tectonics moves Arabia toward Asia. Consequently, layers of sedimentary rock are folding much like a carpet will fold if pushed. The convex upward folds create structures called anticlines, which are prominently seen here. The convex downward folds (between the anticlines) create structures called synclines, which are mostly buried and hidden by sediments eroding off the anticlines. Layers having differing erosional resistance create distinctive patterns, often sawtooth triangular facets, that encircle the anticlines. Local relief between the higher mountain ridges and their intervening valleys is about 1200 meters (about 4000 feet). Salt extrusions and salt "glaciers" are another set of geologic features readily evident in the topography. Salt deposits, likely created by the evaporation of an ancient inland sea, were buried by the sediments that now make up the layers of the anticlines and synclines. But salt is less dense than most other rocks, so it tends to migrate upward through Earth's crust in vertical columns called "diapirs". The compressive folding process has probably facilitated the formation of these diapirs, and the diapirs, in turn, are probably enhancing some anticlines by "inflating" them with salt. Where the diapirs reach the surface, the salt extrudes, much like lava from a volcano, and the salt flows. Two prominent salt flows are evident in the same valley, leaking from neighboring anticlines, just north of the scene center. This shaded relief image was created directly from an SRTM elevation model by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 98.1 kilometers (60.8 miles) by 148.1, kilometers (91.8 miles) Location: 27.3 degrees North latitude, 54.5 degrees East longitude Orientation: North toward the top Image Data: Shaded SRTM elevation model Date Acquired: February 2000
Gotel Mountains, Nigeria and …
PIA04954
Sol (our sun)
C-Band Interferometric Radar …
Title Gotel Mountains, Nigeria and Cameroon, SRTM Shaded Relief plus Height as Brightness
Original Caption Released with Image River drainage patterns provide clues to the rock types and erosional processes involved in landscape evolution. Here in the Gotel Mountains along the border between Nigeria and Cameroon two distinct and highly contrasting patterns are evident. The lowlands in the northern and northwestern parts of the scene exhibit "dendritic" patterns, while the highlands in the southern and southeastern parts of the scene show "rectangular" and other linear drainage patterns. Dendritic drainage patterns appear almost random. Moving upstream, streams split into smaller and smaller channels, with finer and finer spacing, and they show little preference for map orientation other than to complete the pattern. In contrast, rectangular and other linear drainage patterns show a distinct preference for certain orientations in map view. In this scene, the two major preferred orientations are rotated slightly clockwise of north-south and east-west. Linear drainage patterns usually match the cracking patterns that can occur in relatively hard rocks, including igneous rocks such as granite and basalt. Stream erosion typically follows such lines of weakness in these hard rocks. Meanwhile, the randomness of dendritic patterns indicates that no such cracks nor any other geologic structure controls the erosion where that pattern occurs. Given the above, the topographic pattern in this scene appears to tell us the following about the geology of this location. The lowlands are composed of poorly consolidated (relatively soft) rocks or sediments that are at least 100 meters (330 feet) thick and are "massive" (uniform, with no prominent layering at the observed scale). The randomness of the dendritic patterns further indicates that stream erosion is the only significant dynamic process altering the lowland landscape. Forces such as volcanism and tectonics are not altering these landforms. Meanwhile, the neighboring highlands are composed of crystalline rocks, such as granite, that are very hard (generally resistant to erosion) and probably very old. Sometime through their history these rocks cracked, perhaps when they cooled, perhaps under tectonic stress, or perhaps when pressure upon them was relieved when they were unearthed by erosion. Now at the surface, these cracks are zones of weakness as these hard rocks otherwise resist stream erosion. But while the topographic data gives clues, it does not always provide definitive answers. Are the lowlands made up of soft sediments washed in from elsewhere or are they simply rocks "softened" by weathering (disintegration into sand) in place over time. If the latter, might they in fact have been granite also? The two patterns interfinger geographically, suggesting that the rugged highlands may be evolving into the dendritic lowlands. Weathering products (loose sands) tend to accumulate in place in low relief terrain because erosion there is slow to remove them. Also, granites are typically "massive" and cracking patterns, vanish when the rocks disintegrate. The topographic data indeed provide thought provoking evidence, but definitive answers will require fieldwork or other additional evidence. This image was created directly from an SRTM elevation model. A shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. The shade image was then merged with a height-as-brightness image, which helps clarify the continuity of the drainage networks. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 144.8 kilometers (89.8 miles) by 131.5 kilometers (81.5 miles) Location: 7 degrees North latitude, 10 degrees East longitude Orientation: North toward the top Image Data: SRTM elevation shaded plus height-as-brightness Date Acquired: February 2000
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