Africa Splits For New Ocean

One of the topics that I’ve covered frequently at The Daily Galaxy is Earth’s geological history: a fascinating topic, and one that continues to intrigue me. But I never thought I would actually get to witness an act of geological reconstruction beyond a volcano or two happening during my lifetime.

At the Horn of Africa, in a region called the Afar Depression, we are witnessing the birth of what will, eventually, become a new ocean.

No doubt, this is going to take several more million years to happen. The area is pulling apart in two directions, slowly eroding away the earth’s top most layers. The two plates which will eventually emerge are known as the Nubian and Somalian subplates, or protoplates. It has been happening for some 20 million years, and will probably continue for another 10 million before the Red Sea punches right through.

But already the area is suffering from the stresses placed upon it by the continental shifting happening underneath. The continental crust underneath the Afar Depression – an area that overlaps Eritrea, the Afar Region of Ethiopia, and Djibouti – is less than 20 kilometers from top to bottom, less than half its original thickness. And Lake Asal is listed as the lowest point in Africa, measuring some 155 meters below sea level.

The landscape is a roiling hotbed of geological activity. Earthquakes, volcanoes and hydrothermal fields all make the location a difficult place to live in at the best of times. Added to that though, are the scorching temperatures, varying from around 25 °C (77 °F) during the rainy season (September–March) to 48 °C (118 °F) during the dry season (March–September).

The earth’s crust is slowly rifting apart at a rate of 1 to 2 centimeters per year. This is occurring as a result of the presence of a tectonic triple junction, a point where the boundaries of three tectonic plates are meeting.

This region of Earth is simply jam-packed full of geological points. The Afar Depression is home to one of Earth’s great active volcanoes, Erta Ale. It is also one of two places on Earth where a mid-ocean ridge can be studied on land. A mid-ocean ridge is an underwater mountain range, formed by plate tectonics.

Posted by Josh Hill.