This overview of a largely unexplored region helps geologists better understand our restless Earth. Today's astronaut would see man's largest creation, Lake Nasser, if he looked down from this vantage point. Seif dunes, as they are called, are rarely found. The long ridges are parallel to the prevailing winds instead of transverse, like most dunes. The photograph covers tens of thousands of square kilometers of area, but nowhere does one see any signs of life.
Earthquakes occur with great frequency, resulting in massive loss of life and property.
The complex geology of the poorly explored portion of Saudi Arabia known as the Hejaz, north of the Islamic holy city of Medina, is clearly seen. Geologic forms such as lava fields and flows, intrusive and extrusive basalts, extensive faulting, volcanos, playa lakes, as well as dendritic and trellis drainage, can be delineated. The sands of the Arabian Peninsula contrast with the deep blue of the Gulf of Oman and Arabian Sea at Ras al Hadd. The sharp ridges of the Al Akhdar mountains are to the upper left. The view is to the eastward looking across portions of Algeria, Niger, Chad, and most of Libya.