Shaded Relief and Colored Height Mount Saint Helens is a prime example of how Earth's topographic form can greatly change even within our lifetimes. The mountain is one of several prominent volcanoes of the Cascade Range that stretches from British Columbia, Canada, southward through Washington, Oregon, and into northern California. Mount Adams (left background) and Mount Hood (right background) are also seen in this view, which was created entirely from elevation data produced by the Shuttle Radar Topography Mission. Prior to 1980, Mount Saint Helens had a shape roughly similar to other Cascade peaks, a tall, bold, irregular conic form that rose to 2950 meters (9677 feet). However, the explosive eruption of May 18, 1980, caused the upper 400 meters (1300 feet) of the mountain to collapse, slide, and spread northward, covering much of the adjacent terrain (lower left), leaving a crater atop the greatly shortened mountain. Subsequent eruptions built a volcanic dome within the crater, and the high rainfall of this area lead to substantial erosion of the poorly consolidated landslide material. Eruptions at Mount Saint Helens subsided in 1986, but renewed volcanic activity here and at other Cascade volcanoes is inevitable. Predicting such eruptions still presents challenges, but migration of magma within these volcanoes often produces distinctive seismic activity and minor but measurable topographic changes that can give warning of a potential eruption. Three visualization methods were combined to produce this image: shading of topographic slopes, color coding of topographic height, and then projection into a perspective view. The shade image was derived by computing topographic slope in the northeast-southwest (left to right) direction, so that northeast slopes appear bright and southwest slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. The perspective view simulates the geometry of the surface as it would be viewed on a clear day. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 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 Geospatial-Intelligence Agency (NGA) 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 NASA's Science Mission Directorate, Washington, D.C. Size: View distance about 150 km (about 100 miles) Location: 46.2 degrees North latitude, 122.2 degrees West longitude Orientation: View Southeast Image Data: Shaded and colored SRTM elevation model Date Acquired: February 2000 Back to top

On May 18, 1980, Mount St. Helens catastrophically erupted, causing the worst volcanic disaster in the recorded history of the United States. An earthquake shook loose the northern flank of the volcano, and about 2.8 cubic kilometers (0.67 cubic miles) of rock slid downslope in the world's largest recorded landslide. The avalanche released pressure on the volcano and unleashed a huge explosion, which was directed generally northward. The mountain ultimately lost 227 meters (1314 feet) of its height and devastated about 600 square kilometers (230 square miles) of forest. This anaglyph combines a Landsat satellite image with a Shuttle Radar Topography Mission elevation model to show the volcanic crater and most of the zone of devastation. Areas now relatively devoid of vegetation appear bright. Note the landslide debris clogging the northern drainages and forming natural dams (or enlarging previously existing ones). Also note the volcanic dome built up within the crater, and the extensive floating debris still present on Spirit Lake (northeast of the crater) 12 years after the eruption. The stereoscopic effect of this anaglyph was created by first draping a Landsat satellite image over a digital elevation data from the Shuttle Radar Topography Mission (SRTM), and then 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. 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 will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS). Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 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 Geospatial-Intelligence Agency (NGA) 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: 48.0 kilometers (29.8 miles) by 30.3 kilometers (18.8 miles) Location: 46.3 degrees North latitude, 122.2 degrees West longitude Orientation: North at top Image Data: Landsat Bands 1,2,3 averaged as grey. Original Data Resolution: SRTM 1 arc-second (30 meters or 98 feet), Landsat 30 meters Date Acquired: February 2000 (SRTM), 10 August 1992 (Landsat) Back to top

On May 18, 1980, Mount St. Helens catastrophically erupted, causing the worst volcanic disaster in the recorded history of the United States. An earthquake shook loose the northern flank of the volcano, and about 2.8 cubic kilometers (0.67 cubic miles) of rock slid downslope in the world's largest recorded landslide. The avalanche released pressure on the volcano and unleashed a huge explosion, which was directed generally northward. The mountain ultimately lost 227 meters (1314 feet) of its height and devastated about 600 square kilometers (230 square miles) of forest. This stereoscopic view combines a Landsat satellite image with a Shuttle Radar Topography Mission elevation model to show the volcanic crater and most of the zone of devastation. Areas now relatively devoid of vegetation appear bright. Note the landslide debris clogging the northern drainages and forming natural dams (or enlarging previously existing ones). Also note the volcanic dome built up within the crater, and the extensive floating debris still present on Spirit Lake (northeast of the crater) 12 years after the eruption. This stereoscopic image was generated by draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model. Two differing perspectives were then calculated, one for each eye. They 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 and printing 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. 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 will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS). Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 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 Geospatial-Intelligence Agency (NGA) 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: 48.0 kilometers (29.8 miles) by 31.9 kilometers (19.8 miles) Location: 46.3 degrees North latitude, 122.2 degrees West longitude Orientation: North at top Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively. Original Data Resolution: SRTM 1 arc-second (30 meters or 98 feet), Landsat 30 meters Date Acquired: February 2000 (SRTM), 10 August 1992 (Landsat) Back to top