Over the past 5,000 years, East Africa has dried up. Now new research has found that this change may cause the continent to break apart faster.
According to research published in November in the journal, faulting in the East African Rift Zone has accelerated as the level of the Great Lakes has dropped. Scientific reports.
“Typically, it’s something we think about the other way around: Mountains get built, and that changes the local or regional climate,” Scholz told Live Science. “But it can also work the other way around.
Scholz and his colleagues conducted their research at Lake Turkana in Kenya, which is 155 miles (250 kilometers) long, 19 miles (30 km) wide and up to 400 feet (120 meters) deep in places. However, this is nothing compared to the level more than 5,000 years ago, when the lake was up to 500 feet (150 m) deeper.
This was during the African wet period, when much of Africa was wetter than today. In East Africa, this period lasted from about 9,600 years ago to 5,300 years ago, with drier conditions prevailing in the last 5,300 years. Scientists have been studying sediments at the bottom of the lake to determine ancient water levels and sediment fluxes into Lake Turkana. Along the way, they noticed many small fractures and fingerprints of ancient earthquakes in the sediments.
The tectonic plate that lies beneath Africa is separating in East Africa and may one day split into two plates with an ocean between them. The region’s deep, narrow lakes—including Lake Turkana and nearby watercourses such as Lake Malawi in Tanzania and Mozambique—result from this rifting process, which creates deep valleys in the region.
Scholz and his team wanted to know if changes in the lakes themselves were affecting this rifting process. Water is important to tectonics: When glaciers retreat, for example, the lifting of their weight actually causes the ground beneath them to spring up like rising bread—a process called isostatic rebound. Large amounts of water similarly push down on the crust below, potentially affecting processes such as earthquake.
The researchers found that after the end of the African wet season, the faults in Lake Turkana began to move faster, averaging an extra 0.007 inches (0.17 millimeters) of movement per year. In general, Africa is falling apart to 0.25 inches (6.35 millimeters) per year.
Using computer simulations, the researchers found that this seismic acceleration likely has two causes. One is that with less water pressure on the bark, the bugs have more freedom to move: Imagine a face relaxed around two slabs of wood. Another reason is rather indirect. There is a volcano with an active magma chamber on an island on the south side of Lake Turkana. The removal of water from the African wet season decompresses the mantle beneath this volcano, leading to further melting. This melt, in turn, moves into the magma chamber of the volcano, inflating it and leading to further tectonic activity on nearby fault lines.
“During this time interval, we see increased faulting, so more pronounced earthquakes are probably prevalent in this wider area now compared to 8,000 years ago,” Scholz said.
Scientists are now working on a project at Lake Malawi that looks at changes in water levels 1.4 million years ago and hopes to get a better idea of how climate affects the separation of the continents.
“This information about these huge changes in water volume in these lakes is a really important part of the story,” Scholz said.
Muirhead, JD, Xue, L., Moucha, R., Paciga, MK, Judd, EJ, & Scholz, CA (2025). Accelerated rifting in response to regional climate change in the East African Rift System. Scientific reports, 15(1), 38833. https://doi.org/10.1038/s41598-025-23264-9
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