SPACEPHOTOS

The eastern extension of the vast Rub-al-Khali Desert or Empty Quarter, the red and golden dunes (650 feet-200 meters) of the Wahiba Sands in southeast Oman (upper left quadrant) is visible in this southwest-looking view. The predominant winds in the area give the longitudinal dunes the north to south alignment. The mountainous terrain that extends diagonally across the bottom of the image is the Al Jabal al Akhdar or Green Mountain Range, which reach altitudes exceeding 5500 feet (1678 meters). Formed nearly 80 million years ago, the range is a large anticline that is flanked by hard limestone and mantle rocks. Monsoon winds bring moisture-laden air in from the Gulf of Oman (bottom right). As the air rises over the Green Mountain Range, the rising air cools, and rainfall occurs at the higher elevations within the range. Several wadis or waterways drain the Green Mountain Range. Forests are scattered throughout the range.