Remember Pangea? Well, no, you probably don’t. Pangea, a supercontinent that included most of the Earth’s current landmasses, broke apart during the Mesozoic era. Over millions of years, plate tectonics opened up rifts and shifted and moved sections of the continent to new locations around the planet. Those locations — and the size and shape of the continents we know today — are not final, however. Geologists predict that in the next 250 million years, the continents will shift again, bringing Africa and the Americas back together with Eurasia. This spring, it became clear that the process has already begun.
In early 2018, catastrophic rainfall flooded communities and farms in Kenya, causing buildings to collapse and highways to wash out. The floodwaters also caused a deep rift, several miles long and 65 feet across, to open up, sucking in homes, cars, and farms. Eliud Njoroge Mbugua watched the crack open up across the floor of his home, and narrowly escaped before it collapsed. Another family was having dinner when their home cracked in two. Area residents are moving away from the rift. “Staying here is like courting death,” said Mary Wambui, whose house was destroyed.
Some geologists say the rift was just waiting to open up, and seismic activity and tectonic activity eventually reached the soft layers of sediment on the surface. Others say that the rains caused the layers to collapse due to rapid erosion. Regardless of the cause, Kenya is situated along a major active rift zone, so major shifts are inevitable.
“The valley has a history of tectonic and volcanic activities,” said geologist David Adede. “Whereas the rift has remained tectonically inactive in the recent past, there could be movements deep within the Earth’s crust that have resulted in zones of weakness extending all the way to the surface.”
The region, known as the Great Rift Valley, is an active rift zone, where tectonic plates meet and move against each other, or apart. The continent will ultimately break apart on this geologic and geographic line. The new African continent will become two, with most of the country positioned on what is known as the Nubian Plate, while Somalia and parts of Kenya, Ethiopia and Tanzania will form a new continent on the Somali Plate.
The process is accompanied by volcanic and seismic activity, which can initiate sudden and visible breaks between the two plates. That movement impacts not just land, but water. Scientists say that movement of plates creates a super tidal cycle and strengthens the energy generated by the ocean’s waves. A team of researchers created a model that simulated millions of years of tectonic plate movements and changes in the resonance of ocean basins and determined that in several major tidal cycles, the shifting of the plates will eventually return the continents to a Pangea supercontinent state.
“Our simulations suggest that the tides are, at the moment, abnormally large,” said Mattias Green, Bangor University oceanographer and co-author of a new study that discusses the relationship between tectonic plate movements and tidal energy. “And that really was our motivating question: If the tides were weak up until 200 million years ago, and they’ve since shot up and become very energetic over the past two million years, what will happen if we move millions of years into the future?”
That’s right: The entire process takes millions of years, which means these scientists will never find out how close their predictions are to the eventual shape and arrangement of the land masses. In the meantime, the Kenyan government is tasked with repairing highways and trying to fill sections of the rift with rock and concrete. Good luck with that, though. “You cannot stop a geological process because it occurs from deep within the crust of the Earth,” said Adede.
