Falling water levels in one of Africa’s largest lakes, driven by changes in climate, led to a rise in earthquakes, according to a new study led by researchers from Syracuse University and the University of Auckland.
The study has been published in the journal Nature Scientific Reports. Climate plays a key role in modulating the rate of continental rifting, which can drive phases of greater earthquakes or volcanic activity, it showed.
The analysis linked a long-term lake drop of roughly 100-150 metres over the past 6,000 years to measurable increases in fault slip rates within the East African Rift System—a vast tectonic zone where Africa is slowly splitting apart.
The research was conducted on Lake Turkana, the world’s biggest permanent desert lake, stretching about 250 km long and as wide as 30 km, located in northern Kenya. That portion of the country is found in a part of the continent known as the East African Rift Valley, an area home to numerous deep lakes and tectonic fractures.
The researchers examined fault throw rates (the speed at which one side of a fault drops relative to the other) on 27 faults beneath Lake Turkana.
Comparing two windows—the late African Humid Period (9,631-5,333 years before present) and the drier post-Humid period (5,333 years ago to present), the researchers found an increase, with 74 per cent of the faults showing higher post-Humid throw rates and only 11 per cent showing decreases.
Climate-driven changes in lake levels have influenced fault activity and magma production, the findings showed.
Fault lines moved faster, and more magma was produced during drier periods when lake levels were lower, the data revealed.
According to the study, when lake levels drop, the crust effectively lightens, reducing pressure, meaning that faults move more easily and the production of magma under regional volcanoes increases.
These changes, the researchers found, had a profound effect on the Earth’s crust.
According to the study, this is because during drier periods with lower lake levels, less water weight presses down on the Earth’s surface, reducing pressure in the crust.
The study provides the first empirical dataset illustrating changes in time-averaged fault slip rate associated with changing climate regimes in East Africa.
As climate change continues to alter hydrological systems, the study suggests that tectonic and volcanic activity could also be influenced—though such changes would unfold over geological spans.