Ep 4. Sahara

In season 2 of How the Earth Was Made, episode 4 explores the Sahara desert. The Sahara desert is the largest hot desert in the world, covering approximately 3.6 million square miles in Northern Africa. This episode aims to uncover the story of how this seemingly barren landscape was formed.

The episode starts by explaining how the region was once a lush forest with flowing rivers and diverse wildlife. The remains of prehistoric animals such as crocodiles, hippos and fish are still found in the Sahara desert today. However, over time, the climate of the region changed - becoming hotter and drier - leading to the inhospitable desert we know today.

The show takes us back through time to the Paleozoic Era, around 300 million years ago. During this period, the prehistoric landmass known as Gondwana was located around the equator. This landmass eventually broke apart into several continents - including South America, Africa, Australia, and Antarctica - as the Earth's tectonic plates shifted. As a result, the area that is now the Sahara desert was located in the same area as the Amazonian rainforest.

The episode describes how the shift in the Earth's plates caused the formation of mountains that trapped the moisture from the region's coast, creating a humid environment. This initially supported the growth of a diverse range of plant and animal species in the area. However, the shift in the plates also led to the formation of the Nile River, which eventually diverted from its path to the East and flowed North into the Mediterranean Sea. This diverted the river system from the Sahara region, resulting in the drying out of the region.

Over time, temperatures in the Sahara desert increased and permanent sand dunes formed as winds blew the exposed waterways and sand of the region. The show explains how the effects of this arid environment can be seen across the region today, such as the rock formations and sand dunes that appear throughout the desert.

The episode also explores the idea of the Sahara desert expanding and contracting over time. Through scientific evidence and research, experts have found that there have been periods where the region was cooler and wetter, allowing for a return of vegetation and the formation of freshwater lakes.

How the Earth Was Made season 2, episode 4 provides an in-depth look into the geological and environmental forces that transformed the Sahara region from a diverse, lush landscape into the vast, searing desert we know today. The show combines stunning visuals, scientific research, and expert analysis to tell the story of this unique region's natural history.