Newly released topographic data sets from NASA and the National Geospatial-Intelligence Agency (NGA) provide twenty first century explorers new ways to traverse the wonders of Africa, the Arabian Peninsula and Madagascar.
Courtesy of the Shuttle Radar Topography Mission (SRTM), African topography can be studied and understood as never before. SRTM is a cooperative project of NASA, NGA, the German and Italian space agencies.
The exotic and often harsh terrain portrayed in movies like “Out of Africa,” “The African Queen,” and “Lawrence of Arabia,” is shrouded in mystery to many Westerners. The vast, often inaccessible territory has some of Earth’s most diverse, extreme and breathtaking topography, much of it hidden behind a veil of persistent cloud cover.
Dr. Michael Kobrick, SRTM project scientist at NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., said the new data are a hot commodity. “The demand for Africa and Arabia digital elevation data is brisk. The data are being used for varied applications such as studies of earthquakes, volcanism and erosion patterns,” he said.
To embark on a safari of 12 new compelling images and a new fly-around animation, visit:
http://www2.jpl.nasa.gov/srtm/africa.htm
The new data represents about one-fourth of the total from the mission. The SRTM radar system mapped Earth’s topography between 56 degrees south and 60 degrees north of the equator in February 2000. The resolution of the data is three arc-seconds, which is 1/1,200 of a degree of latitude and longitude, or about 90 meters (295 feet). While that’s not quite good enough to spot a snake in the Serengeti or corral a Saharan camel, it’s more than enough to capture our imaginations, and pique the interests of scientists.
“The shape of Earth’s surface affects nearly every natural process and human endeavor,” said Dr. John LaBrecque, manager, Solid Earth and Natural Hazards Program, NASA Headquarters, Washington. “One interesting African application is Mount Kilimanjaro. Its glaciers are rapidly shrinking and expected to disappear soon, if the rates continue. By combining satellite imagery with elevation data, scientists can better monitor and understand environmental changes,” he said.
Africa’s topography is diverse. The northern continent consists of plateaus and basins, many of which filled with sand and gravel to create the Sahara. The converging African and Eurasian tectonic plates created the Atlas Mountains. Africa’s central latitudes are dominated by the Great Rift Valley, a geological fault system. To the west lies the vast, shallow Congo Basin. Most of southern Africa rests on a plateau comprising the Kalahari basin and a mountainous fringe, skirted by a coastal plain that widens out in Mozambique.
The Arabian Peninsula, the southwest part of Asia, split from Africa about 30 million years ago. Abrupt cliffs along the Red Sea and Gulf of Aden provide evidence of this massive rip in Earth’s crust. The peninsula’s northeastward migration is also evident in topography. It collides with the rest of Asia to form mountains in Iran, and it slides past the Mediterranean region to create the Dead Sea fault. At the Dead Sea some stretching accompanied the sliding, which created Earth’s lowest land elevation.
Previous SRTM releases covered Eurasia, North and South America. The final release this summer will include Australia, New Zealand and various islands. Together, these data constitute the world’s first high-resolution, near-global elevation model.
The NGA one arc-second (30 meters or 98.4 feet) data products for the United States and territorial islands are also available on the Internet, at:
http://edc.usgs.gov/
NASA processed input into research-quality digital elevation data. The NGA provides additional processing to develop mapping products. The U.S. Geological Survey Earth Resources Observation Systems Data Center provides final archiving and data product distribution. For information about SRTM on the Internet, visit:
http://www.jpl.nasa.gov/srtm