During the past 6,000 years, a decline of 100-150m in Lake Turkana’s level diminished pressure on the Earth’s crust, resulting in increased local quake activity, according to Muirhead and collaborators at Syracuse University in the US.

“We tend to think of earthquakes and volcanoes as being driven purely by deep forces inside the Earth,” says Muirhead, of the School of Environment. “But what we’re seeing here is that surface processes – like climate and rainfall – also play a role.

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, according to the study in Nature Scientific Reports.

The study is the first empirical evidence of the effect in the East African Rift System, the scientists say.

Similar studies in Iceland and the western United States have linked a decreased weight of glacial ice to increased tectonic activity.

Lake Turkana, in northern Kenya, is the world’s biggest permanent desert lake, stretching about 250km long and as wide as 30km, and sits at the heart of the East African Rift, where the African continent is slowly splitting apart.

The area is known as the cradle of humankind for the rich trove of fossils showing human evolution.

“Climate change, whether human-induced or not, will likely impact the probability of future volcanic and tectonic activity in East Africa,” Muirhead says. “However, these changes occur over geological rather than human timescales, so their effects would be subtle and largely imperceptible within a single lifetime or even across generations.”

Researchers from Syracuse collected data across 27 faults below the lake and the senior author of the study was Professor Chris Scholz, of Syracuse. Muirhead conducted much of the research and analysis as a postdoctoral associate in Scholz’s lab.

“Continental break-up is generally thought of as a process fundamentally rooted in plate tectonics,” says Scholz. “Our research shows that rifting is also shaped by surface processes, including regional climate.”