Well throw your globes out the window boys and girls, the field of geography is about to get exciting!
We are not talking about erosion or your average run of the mill volcano eruption. We are talking about the fact that the wheels are in motion for the creation of a brand new ocean—one forming right in the middle of Africa.
Now that’s a crack
It began in 2005. George W. Bush started his second term as 43rd President of the United States, Hurricane Katrina flooded roughly 80% of the city of New Orleans, and Mariah Carey’s “We Belong Together” topped the Billboard 100 charts. Oh yes, and a 35 mile (60 kilometer) long crack opened up in the Afar desert in Ethiopia. As far as we can tell, the previous three events were unrelated to the new fissure…but the jury is still out on Mariah.
The crack opened up in a matter of days, and was as much as 20 feet wide (about 6 meters) at some points.
Volcanic eruptions and tectonic plates; never a good combination
For the geography of a region to change this much and this quickly was pretty astonishing, but there is a reason for it. This area of Africa is on the border of two tectonic plates. These plates are divergent, meaning that they move away from each other instead of colliding with each other. Volcanic eruptions along tectonic plates spew out magma that can force the plates apart, but this typically happens at the bottom of the ocean where we can’t see it particularly well.
In this case, a volcano named Dabbahu, located in the Afar desert, erupted and unzipped the tectonic plates. 2.5 cubic kilometers of magma forced itself up between the tectonic plates pushing them apart and creating the rift we now see. Just so you know, 2.5 cubic kilometres of magma is the equivalent of 1 million Olympic-sized swimming pools of red-hot fiery death.
Slow and steady wins the race…
The movement hasn’t stopped either. The crack continues to expand at a rate of a bit less than one inch per year (about two centimetres) as additional earthquakes (12 between 2005 and 2008) shake the area, and more magma is forced to the surface. The new layer being formed is similar to the crust that exists at the bottom of the ocean.
Professor Cynthia Ebinger, professor of earth and environmental sciences at the University of Rochester says this about the crack and what is occurring:
It’s actually not an unusual process in terms of Earth’s history. This process is happening along mid-ocean ridges worldwide. But by the time a ship is mobilized, we may have missed all of this activity. Here, this is one of the few places on the surface of the earth right now where we have this process occurring.”
The slow expansion of the crack will tear the Afar desert area and the horn of Africa away from the rest of the continent. That alone doesn’t make an ocean, but there are a number of factors at play here. The crack occurs in an area known as the Afar triangle (or Afar depression). This area contains the lowest point in Africa—Lake Asal, Djibouti—which is 155m (or 509ft) below sea level.
The map of Africa is going to have a lot more blue in it
Dr. James Hammond, a seismologist from the University of Bristol and member of the research teams in Afar, explains how the ocean is only cut off by about a 20-metre block of land in Eritrea. One inch per year might not seem like a lot, but 20 metres (65.5 feet) is not a large distance either in the grand scheme of things. As soon as a connection between land and water is established, the new area will take on water from the Red Sea and the Gulf of Aden, submerging the areas below sea level.
Eventually the map of Africa could look a lot more like this:
It’s going to take time
One small crack in the ground gives birth to a new continent and a new ocean as well. Talk about a powerful change! Don’t grab your surfboard yet though, Professor Cynthia Ebinger estimates that it will take between 100,000 and one million years before the ocean forms. But in geographic terms, that is just the blink of an eye.