Rift valleys get their name from the geological process of rifting. Rifting occurs when tectonic plates move away from each other.
What is a rift valley?
Many rift valleys are part of a triple junction. This is a type of divergent boundary between three tectonic plates. You can think of it kind of like a pie cut into three pieces. Each piece of pie is a different tectonic plate but they all touch in the middle where the valley is.
Some rift valleys form at transform faults. Transform faults are boundaries where tectonic plates grind past each other.
What makes rift valleys different?
Unlike valleys formed by rivers or glaciers, rift valleys can occur both on land and at the bottom of the ocean.
The Great Rift Valley
The largest and most famous rift valley is the Great Rift Valley.
Over 4,000 miles long, the Great Rift Valley extends from areas in the Middle East through eastern Africa. We call the African part of the valley the East African Rift System. Comprised of many rift valleys, The Great Rift Valley system is part of a triple junction. The Somalian, Nubian, and Arabian plates rift at this intersection. The primary rifts of the East African Rift System include the Western Rift and the Eastern Rift. These rifts date back over 25,000,000 years.
What makes the Great Rift Valley so interesting?
Some of the earliest examples of human life came from the Great Rift Valley. Our ancient ancestors lived in the valley about 200,000 years ago. This might be because of the plethora of plants and animals available there. The Great Rift Valley is home to many different species of wild animals.
The Eastern Rift has lakes that are shallower but have high mineral content. Geologists study the East African Rift System to understand how continents break apart and move. We call this process continental drift.
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