Ethiopia’s Geological Activity: Understanding Earthquakes and Volcanism

Ethiopia’s Afar region is experiencing significant seismic and volcanic activity due to its location on the Great Rift Valley. This region’s geology involves molten rock movement leading to earthquakes and potential volcanic eruptions. Observations reveal over 200 quakes recently, with concerns about future volcanic activity, highlighting the need for enhanced monitoring and community preparedness.

The recent swarm of earthquakes and concerns over volcanic eruptions in January prompted the evacuation of tens of thousands from Awash Fentale in Ethiopia’s Afar region. This area is located within a geologically active section of the Great Rift Valley, which has a record of volcanic activity and earthquakes spanning the last 800 years, with notable eruptions in 1250 and 1820 AD.

The geological events presently observed in Fentale are part of a protracted process evolving over millions of years, occurring beneath the Earth’s surface. Researchers recognize this area as a natural laboratory, suggesting that it may eventually lead to a continental split, forming a new ocean along the East African Rift Valley, as discussed by Gemechu Bedassa Teferi, an expert on the region’s volcanoes.

The origins of tremors and volcanism in Ethiopia can be traced back eighteen million years when the continents separated to form the Red Sea and Gulf of Aden. Approximately eleven million years ago, a fissure appeared under the Afar Depression. The area lies on a hot semisolid mantle layer, which is perpetually moving due to geothermal heat. This movement allows molten rock to rise, resulting in volcanic eruptions through weaknesses in the Earth’s crust.

Additionally, beneath the surface, the molten rock is contributing to the divergence of the ground. This creates a rift that is subsequently filled with molten rock, leading to friction, which causes rocks to crack and release energy as seismic waves, manifesting as earthquakes. The Afar region is recognized as one of the globe’s most active volcanic and tectonic zones.

Recent seismic activity includes more than 200 recorded earthquakes exceeding magnitude 4, with the strongest measuring 6 on the Richter scale. The tremors have resulted in structural damage in nearby areas, including the capital, Addis Ababa, located approximately 190 km from the quake’s epicenter. Notably, a substantial earthquake in 1989 reached a magnitude of 6.5, causing damage to inadequately constructed buildings.

Historically, the last eruption in Fentale occurred in 1820, and there is a correlation between earthquakes and forthcoming volcanic activity. This has raised concerns that the current seismic activity may foreshadow eruptions at two nearby active volcanoes. Satellite radar data indicate that these earthquakes stem from molten rock pushing upwards from significant depths below Awash Fentale.

Potential outcomes of this geological activity vary based on several factors, including the temperature and viscosity of the molten rock and the resistance of surrounding materials. Three possible scenarios exist: cooling of the rock leading to solidification, volcanic eruption from the upward movement of the molten material, or lateral propagation of extremely hot molten rock that interacts with other materials, potentially resulting in either cooling or volcanic eruption.

Given the complexity and uncertainty surrounding these geological processes, enhanced predictive measures are essential for mitigating future hazards. Scientists advocate for increased monitoring through techniques such as volcanic gas analysis, GPS tracking, and geophysical assessments. Additionally, fostering collaboration between scientists and government officials is crucial for developing effective communication channels to inform at-risk communities.

Ethiopia’s geological activity is influenced by historical continental separation and underlying molten rock movement. The recent earthquakes and potential volcanic eruptions signal a dynamic geological environment, necessitating improved monitoring and predictive efforts. The collaborative engagement of scientists and officials is critical for preparing communities for possible hazards associated with these natural processes.

Original Source: theconversation.com