A swarm of earth tremors and fears of volcanic eruptions in January forced tens of thousands of people to move away from Awash Fentale, an area in the Afar region of Ethiopia. The area falls within a geologically active region of the Great Rift Valley that has experienced a number of earthquakes and volcanic events in the last 800 years. Two major volcanic eruptions occurred in 1250 and 1820 AD.

What unfolded in Fentale in 2025 is part of an ongoing process millions of years in the making, deep under the earth’s surface. Scientists see it as a fascinating natural laboratory that will culminate in a north-south continental split—and ultimately create a new ocean—along the great East African Rift Valley. Gemechu Bedassa Teferi, a researcher who studies the volcanoes of the Main Ethiopian Rift, unpacks what’s behind the recent events.

What causes tremors and volcanic eruptions in this region of Ethiopia?

Eighteen million years ago, the continents broke apart to form the Red Sea and the Gulf of Aden. Around 11 million years ago, a crack formed deep under the present Afar Depression, an area of north-east Ethiopia.

The region sits on a hot, semisolid layer called the mantle. This mantle is constantly in motion due to the heat from the deeper part of the earth. One result is that the heated semi-solid rock (molten rock) can be forced up from the mantle and erupt through the weak spots in the earth’s crust. This is called a volcanic eruption.

Deep beneath the surface, the molten rock is also enabling a parallel process of the ground moving apart. This creates a gap—called a rift—which is eventually filled by the molten rock. The friction created results in rocks suddenly breaking and releasing enormous amounts of energy. The released energy radiates outward in the form of seismic waves like ripples on water, causing the ground to shake. This is what is felt as the so-called earthquake.

The Afar region is one of the most volcanically and tectonically active areas in the world.

The ongoing events in Fentale, as well as the Dofan area to the north, are the most recent in the history of molten material rising to the surface as parts of the earth’s crust move apart from each other.

No volcanic eruption has occurred in the most recent events. But more than 200 quakes with a magnitude of more than 4 have been recorded in the last five months. The strongest of these measured at 6 on the Richter scale.

The swarm of earthquakes damaged dozens of buildings, schools, roads and factories. Most residents in the capital, Addis Ababa, which is nearly 190km away from the epicenter (starting point for an earthquake), also felt the tremor.

The strongest earthquake since 1900—in 1989—had a magnitude of 6.5 on the Richter scale. This is strong enough to damage old buildings or those not built to withstand earthquakes.

The last volcanic eruption at Fentale occurred in 1820. Based on historical records and global trends, an earthquake is a common precursor to volcanic eruptions. This has fueled fears that recent earthquakes could signal eruptions at two nearby active volcanoes.

What can scientists learn from the current events?

Satellite radar images of the Fentale area revealed that the earthquakes in the region are due to hot molten rock pushing its way up from about 10km below Awash Fentale.

What could follow is complex and depends on several factors, such as:

• the temperature of the molten material—the hotter it is, the more easily it flows
• the viscosity (how thick it is)— thicker molten rock flows slowly
• the strength of the surrounding material—strong, resistant rocks around the hot molten rock can resist the pressure to rise.

Three scenarios could possibly play out under Fentale.

The first possible outcome is the cooling of the molten rock. That would lead to the formation of a dense, solidified rock material.

The second is that the molten material could cause an eruption after forcing its way vertically to the surface or moving laterally underneath the earth’s surface.

Under the third scenario, the super hot molten rock may also propagate laterally, interacting with other molten materials. This could eventually lead to either cooling or a massive volcanic eruption.

Still, there are other unknown factors that could affect these potential processes in a geologically dynamic region.

This calls for better predictions to mitigate future hazards. Scientists suggest that scientific monitoring techniques should be employed. These include volcanic gas measurement, onsite GPS monitoring, and geophysical study. Equally important is the collaborative effort of scientists and government officials to create a communication channel to engage the at-risk community.

This article is republished from The Conversation under a Creative Commons license. Read the original article.