In the remote Afar depression in northern Ethiopia, the African continent is slowly splitting apart. This rifting will eventually form a new ocean, although it will take about 10 million years.
In September 2005, a series of fissures suddenly opened along the depression, accompanied by earthquakes and ash clouds which darkened the air for three days.
Usually, the Earth’s plates only move by a few centimetres per year, but here, a 60 kilometre stretch of the rift pulled apart by 8 metres, and dropped by up to 2 metres, over the course of about a week. Nearby volcanoes meanwhile subsided by around 3 metres.
New seafloor is created when plates move apart. This process is normally hidden deep beneath the oceans, but in Afar new oceanic crust is being created at the Earth’s surface. The only other place where this happens is Iceland.
The event gave scientists a unique opportunity to monitor how the surface of the Earth reacts as it is stretched and splits apart, and also how the magma intrudes into this thin crust, using seismometers and GPS instruments alongside satellite radar data.
How the Earth’s crust is breaking apart
Scientists at Addis Ababa University alerted the world to the incredible geological activity in 2005. The initial research led to a major international collaboration, the Afar Rift Consortium, led by COMET Director Tim Wright. This initiative aimed to improve understanding of how continents split apart and new oceanic crust is formed, as well as to raise awareness and build resilience to the seismic and volcanic hazards in the area. The consortium was a major international collaboration involving scientists in Ethiopia, the UK, the US and France.
Between 2005 and 2010, the team was able to study a rare sequence of 13 magmatic events, where hot molten rock was being intruded into a crack between the African and Arabian plates. They found that the intrusions were linked as each event changed the amount of tension in the Earth’s crust.
Synthetic Aperture Radar Interferometry (InSAR) was also used to measure how the Earth’s surface was changing, due to magma collecting beneath a volcano or because of the tectonic plates moving.
In 2014 a follow-on consortium was funded by the UK Natural Environment Research Council. The RiftVolc project, co-led by COMET scientist Juliet Biggs, aims to research past and current volcanism and volcanic hazards in the central Main Ethiopian Rift
TV and media coverage has led to a significant increase in public understanding of geohazards in Ethiopia. This helps with hazard preparedness, which can in turn and protect lives and livelihoods.
Examples include the landmark Earth sciences series from the BBC, Earth: Power of the Planet, and the Discovery Channel’s Faces of Earth, as well as coverage in the Guardian, Metro, Der Spiegel and Science News.
The team also took part in the 2010 Royal Society Summer Science exhibition. The consortium’s “Fast and furious: witnessing the birth of Africa’s new ocean” allowed approximately 50,000 visitors to see an 3D interactive movie of the Afar region, examining how the surface geology changes when the land splits apart. At the seismometer stand visitors could jump up and down to create their own earthquakes as well as learn how scientists use earthquakes to understand how the Earth is evolving.
Business investments and opportunities
Exploitation of geothermal activity in Afar and the Main Ethiopian Rift is ongoing through Reykjavik Geothermal, a company specialising in harnessing these resources for clean dependable energy. They are establishing a new company, Corbetti Geothermal Power, which aims to open a geothermal power plant in the next 5 years.
They are also working with RiftVolc to understand the magmatic and geothermal systems underneath Corbetti and other volcanoes in the Ethiopian Rift.