Observing Sahara Geology

[billstack]

While cruising over the Saraha Desert in southern Algeria at FL330 in MSFS, my attention was drawn to something unexpected.

The Sahara Desert is usually depicted as entirely sand, so mountains in southern Algeria seemed out of place. They are ridges and valleys much like southern Appalachia, but they are barren rock – sans any vegetation. So I looked them up online.

 

Wide swaths of the Sahara are solid rock with a little wind-blown sand. The region’s rocks are metamorphic and estimated at two billions years old. The highest is almost 10,000 feet (3,000 meters) above mean sea level. Some mountains are eroded into odd shapes by blowing sand. Similar ridges and valleys are seen in the Congo area, but they are vegetated and eroded by water.

 

 

Africa comprises five tectonic plates that have been lifting and crinkling the topography one earthquake at a time for hundreds of millions of years.

Mixed among the Sahara’s ridges and valleys are solidary conical mountains – telltale volcanoes. The region has a respectable share of more than 100 dormant and active volcanoes in Africa. The Atakor volcanic field in southern Algeria comprises lava domes, lava flows, craters, and vents releasing volcanic gasses. Terrain approaches almost 10,000 feet elevation with deep gorges among the crests and peaks. Volcanic activity ranges from 20 million years ago to the present with ongoing venting of volcanic gases and frequent seismic activity.

This huge desert seems barren from aloft, but a few oases such as El Golea, In Salah, and Tamanrasset have enough water to support human activities. Their urbanization and airports are represented in MSFS 2020.

 

 

High-altitude cruises over the region provide excellent overviews. Low-altitude cruises reveal fascinating details of the topography and villages even though satellite imagery in MSFS lacks definitive details. My screen shots show the Ahaggar Mountains near the oasis city of Tamanrasset, the lava fields near another oasis city In Salah, and isolated dormant volcanoes in the region.

 

 

This often ignored region is more geologically interesting than I knew.

Bill Stack is a flight-sim expert and author of tutorial books and videos for flight simmers who want truly realist simulations.