Understanding Earth’s Dynamics: Earthquakes and Volcanoes in Ethiopia
In January, tremors and volcanic eruption fears in Ethiopia’s Awash Fentale region forced thousands to evacuate. This area, part of the geologically active Great Rift Valley, has a history of seismic and volcanic activity. Geologist Gemechu Bedassa Teferi explains that these events are tied to tectonic movements beneath the Earth’s surface and highlights the need for better monitoring and preparedness strategies.
In January, a series of earth tremors and concerns of volcanic eruptions in Ethiopia prompted the evacuation of tens of thousands from Awash Fentale, located in the geologically active Afar region. This area is part of the Great Rift Valley, which has experienced significant seismic and volcanic activity over the past 800 years, including two notable eruptions in 1250 and 1820 AD.
The geological processes occurring in Fentale are part of a much older, ongoing phenomenon that could ultimately lead to the splitting of continents and the formation of a new ocean through the East African Rift Valley. Geologist Gemechu Bedassa Teferi provided insight into the triggering factors behind these seismic and volcanic activities.
Approximately 18 million years ago, the breakup of continents resulted in the formation of the Red Sea and Gulf of Aden. Around 11 million years ago, a fissure developed beneath what is now the Afar Depression in northeastern Ethiopia. The region lies above a hot, semi-solid layer known as the mantle, which is in constant motion due to internal heat.
As the heated molten rock rises from the mantle, it can erupt through weak spots in the Earth’s crust, resulting in volcanic eruptions. Concurrently, the movements of molten rock lead to a process of rifting, characterized by ground separation, which generates quick breaks in the rock and substantial energy release, causing earthquakes.
The Afar region is renowned for its volcanic and tectonic activity. The events unfolding in Fentale, along with activities in the nearby Dofan area, signify a surge in molten rock reaching the Earth’s surface as tectonic plates separate. Despite no volcanic eruptions during the recent quake outbreaks, over 200 tremors with a magnitude exceeding 4 have been recorded in five months, with the strongest reaching 6 on the Richter scale.
These seismic activities have led to widespread structural damage, affecting buildings, schools, roads, and factories, with tremors felt as far away as Addis Ababa, located approximately 190 kilometers from the epicenter. Notably, the strongest earthquake recorded in the region since 1900 occurred in 1989, measuring 6.5 on the Richter scale.
The last volcanic activity in Fentale was noted in 1820. Historically, earthquakes have often preceded volcanic eruptions, leading to concerns that recent seismic events may herald eruptions in nearby active volcanoes.
Recent satellite radar imagery indicates that the quakes in Fentale are linked to molten rock pushing upwards from around 10 kilometers below the surface. The potential outcomes are uncertain but hinge on various factors including the temperature, viscosity, and the strength of surrounding materials.
Three possible scenarios may arise: the cooling of molten rock into dense solid material, a volcanic eruption following a vertical ascent, or lateral movement of the molten rock interacting with other hot materials, possibly leading to eruptions or cooling.
These unpredictable geological dynamics highlight the necessity for improved monitoring and forecasting to safeguard vulnerable communities. Implementation of monitoring techniques such as volcanic gas assessments, GPS monitoring, and geophysical studies, in addition to coordinated efforts between scientists and government officials, is crucial to enhance communication with at-risk populations.
In conclusion, the seismic and volcanic activities in Ethiopia’s Awash Fentale are the result of complex geological processes linked to the region’s position within the Great Rift Valley. Understanding the dynamics of these events is essential for predicting future occurrences and mitigating risks to affected communities. Collaborative efforts in scientific monitoring and community communication are vital for enhancing safety and preparedness in this active geological zone.
Original Source: theconversation.com
