Climate shifts and a deepening rift 

November 15, 2025

New research shows that long-term climate shifts and falling water levels in one of Africa’s major lakes played a direct role in increasing earthquake activity in the region. The study, conducted by scientists from Syracuse University and the University of Auckland, examines how declining lake levels in Lake Turkana altered the geological forces beneath the East African Rift System. Their findings, published in Nature Scientific Reports, suggest that climate can influence the pace at which continents split and reshape the Earth’s crust.

Lake Turkana, located in northern Kenya, is the world’s largest permanent desert lake. It sits within the East African Rift Valley, a vast tectonic zone where the African continent is slowly pulling apart. Over the past 6,000 years, the lake’s water level fell by nearly 100 to 150 metres. The researchers linked this major decline to measurable changes in fault activity deep below the surface.

The team examined fault throw rates on 27 faults beneath Lake Turkana. Fault throw refers to the speed at which one side of a fault shifts downward relative to the other. To understand how climate influenced these movements, the scientists compared two distinct periods: the late African Humid Period, from about 9,600 to 5,300 years ago, and the much drier era that followed. Their results showed a clear pattern. About 74 percent of the faults exhibited faster movement during the drier period, while only 11 percent slowed down.

According to the study, the chain of events begins with declining lake levels. When the lake shrinks, the weight of water pressing down on the Earth’s crust reduces. This change lightens the crust and lowers the pressure that typically holds faults in place. As a result, the faults can slip more easily. At the same time, reduced pressure beneath the surface allows magma to accumulate and move more freely, increasing volcanic activity in nearby regions.

These findings highlight the link between climate change, hydrological systems, and deep geological processes. As the climate grows drier, lakes contract. This shift affects the balance of forces in the crust, altering fault movement and the flow of magma. The researchers note that the changes they observed unfolded over thousands of years. While modern climate change is expected to alter rainfall and lake levels across East Africa, any impact on tectonic or volcanic activity would also occur on similar geological timescales.

The study provides the first empirical evidence from East Africa showing how long-term climate conditions can shape the rate at which continents split apart. It also underscores the complex relationship between climate, water, and the deep processes that continually reshape the planet.