Scientific observations are made every day, and yet we rarely are able to comprehend the changes our Earth experiences on a grand scale. Small movements, blips on the radar, and non-dramatic shifts in the geography and biology of our world may not seem like great alterations in our environment, but in totality can result in major changes in the composition of where we live.
For instance, the tectonic plates that make up the foundation of Earth’s land masses move, shift, and grind away at one another on an incredibly small scale. These movements can result in dramatic events, like earthquakes and volcanic eruptions, but most often are slow and quiet. Over an incredibly long timescale, these movements can result in new continents being born, mountain ranges growing, and new oceans forming.
Introduction to African Rifts
Imagine being able to watch the creation of a new continent and, potentially, a new ocean. Although this is a slow process by human standards, we are able to do just that in eastern Africa.
This wildly interesting part of the world is home to the confluence of the Nubian, Somali, and Arabian tectonic plates that have helped form rifts running south into Kenya and Tanzania, northwest to the Sinai, and east to Aden. Eventually, these rifts could split Africa into pieces and create a new ocean that would form in the rift valleys.
These tectonic plates are moving away from one another at a spread of 1-1.5 cm per year and will stop when the forces behind them quit or, more likely, when they run into another tectonic plate.
There is much that science still doesn’t understand about the boundaries of tectonic plates and what drives them apart and together. The ongoing research in Africa is helping to fill in some of these knowledge gaps while also creating even more questions that we have to answer about how our Earth moves and behaves.
Tracking Rift Development in the Afar Region
Scientists have the unique opportunity to watch the creation of a new landmass and potentially the emergence of a new ocean in Ethiopia’s Afar region many millions of years in the future. Hot and inhospitable, the Afar nevertheless attracts researchers who are studying the creation and expansion of rifts in real time.
The Great Rift Valley, perhaps Africa’s most known rift, is just one of many geologic formations that have been created on the African continent by the movement of tectonic plates.
The movement of the Somali, Nubian, and Arabian plates have caused the Red Sea Rift, the Aden Ridge, The Malawi Rift, and the East African Rift. The tectonic plates are shifting at different rates creating fissures, volcanos, seismic activity, and plenty of research opportunities.
Africa’s rifts get younger the further south you look. To Africa’s north, rifts have caused the Red Sea, the Gulf of Aden, and the Great Rift Valley. As you travel south, volcanoes of different compositions help mark tectonic boundaries and showcase the unique characteristics of rifts at various stages of creation.
Rift Formations and Volcanic Clues
One unique volcano is Erta Ale in Ethiopia. Erta Ale is one of two volcanos with an active lava lake, joining Hawaii’s Kilauea volcano. The lava lake at Erta Ale was first observed in 1906, making it the oldest continuous lava lake in the world.
This region is of particular interest to researchers who are studying the creation of rifts as well as the mechanics behind the formation of tectonic plate boundaries. Some researchers think that the magma formations below Erta Ale indicate a shift from a rift volcano to a mid-ocean ridge volcano, indicating a future where Africa is transected by a new body of water.
The rifts south of Erta Ale mimic the characteristics of a mid-ocean ridge, according to some scientists. One theory is that the magma below this region, also known as the Afar plume, is heating up the land beneath the rift as it spreads. This series of movements is similar to the forces that led to the creation of the Atlantic Ocean. However, just because we’ve identified an area where continental rifting is occurring isn’t a guarantee that an ocean will form.
While the majority of tectonic plate activity is small and nearly unnoticeable unless you’re looking for it, other events are dramatic and remind us that the ground we walk on isn’t as stable as it seems. A rift that was several kilometers long emerged in southwestern Kenya, exposing an area that may have been an erosional gully from a preexisting fault line. This area encompasses the boundary of the Somali and Nubian plates and may have been an indicator of new plate boundaries. The mechanics of plate boundaries are, in many ways, still a mystery.
Another extreme event occurred in 2005 in Ethiopia when a rift 35 miles long opened up. This is equivalent to several hundred years’ of rift activity focused on one event. While some researchers are focused on the activity of rift volcanoes, others look at these extreme events to try to discover what unique forces are at work that prompt such scenarios.
Advances in satellite and GPS technologies have made visualizing the movement of tectonic plates that much more feasible. GPS trackers are able to detect movements of a few millimeters, giving scientists data on tectonic plate movements at a much smaller scale than previously possible.
Satellite imaging can detect the thickness of the Earth’s layers in rift valleys, showing the transformation from older rift areas in more northern Africa to the newer, developing rifts in the southern part of the continent.
Although it will take many millions of years to see whether these rifts will form a new ocean or not, the data being gathered today can help us understand the mechanics behind these incredible processes.
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Diaz, Lucia Perez. Africa is splitting in two- here is why. 29 March 2018. Retrieved from https://theconversation.com/africa-is-splitting-in-two-here-is-why-94056
Klemetti, Erik. Are We Seeing a New Ocean Starting to Form in Africa? 8 May 2020. Retrieved from https://eos.org/articles/are-we-seeing-a-new-ocean-starting-to-form-in-africa