Western Tibet, Shaded Relief with Color as Height
The 5000 meter (16,000 feet) high Tibetan Plateau has been formed by the collision of the Indian subcontinent with central Asia. The topography rises from the Indus-Ganges plains across the Himalayas and into the lower relief central part of the plateau. The north edge of the plateau is the Altyn Tagh and Kun Lun mountain range. North of Tibet is the Takla Makan desert. Two major faults in western Tibet stand out in the topography and satellite imagery. The Karakoram Fault is the straight line running from top left to lower right across this image, through the Karakoram mountains and southern Tibet. The Altyn Tagh Fault is the slightly curved line running along the northern edge of the plateau from top left to top right.
Geologist s and geophysicists have long argued about how fast these two faults in western Tibet are moving. In one model, the Tibetan plateau is like a watermelon seed sliding out to the east along these two faults. In another model, Tibet is deforming internally without sliding rapidly sideways. Scientists at the Centre for Observation and Modelling of Earthquakes and Tectonics and at NASA's Jet Propulsion Lab have used interferometric analysis of radar data from the European Remote Sensing satellites and topographic data from the Shuttle Radar Topography Mission to study the faults in western Tibet. The interferometric analysis was performed with software developed at JPL. The results show that the faults in western Tibet, especially the Karakoram Fault, cannot be moving rapidly. This rules out the watermelon seed "extrusion" model, at least for western Tibet.
These results are published in the journal Science, Volume 305, Issue 5681, pages 236-239, July 9, 2004, available at (subscription required for full text): http://www.sciencemag.org/.
This shaded relief with color as height image was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) 3-arcsecond (90-meter, 300 feet) data and from the GTOPO30 data (30 arcseconds, 900 meters, 3000 feet spacing). Elevations vary from about 200 meters (600 feet) in purple shades above sea level in the plains of India to over 7700 meters (25,000 feet) in the Himalayas (white) within this image.
Radar data used in this research were acquired by the European Remotes Sensing (ERS) satellites operated by the European Space Agency, which kindly made this data available for research. Research was performed at the Centre for the Observation and Modelling of Earthquakes and Tectonics supported by the U.K. Natural Environment Research Council. Part of this research was performed at the Jet Propulsion Laboratory, California Institute of Technology under contract with the U.S. National Aeronautics and Space Administration.
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, and the GTOPO30 data produced by the U.S. Geological Survey Eros Data Center. 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, DC.
Size: Image width 320 kilometers (200 miles) and height 850 kilometers (530 miles)
Location: 35 degrees North latitude, 79 degrees East longitude at center
Orientation: North is up, Universal Transverse Mercator projection, zone 44
Resolution: pixel size is 80 x 80 meters (262 x 262 feet)
Date Acquired: February 2000 (SRTM)