Scientists monitor activity at Corbetti and Alultu
Scientists deployed monitoring equipments on two Ethiopian volcanoes that would provide real-time tracking of eruptions and forgo repairs of seismic equipment.
A team led by scientists from the University of Bristol in England, placed ground based GPS monitoring equipment that will measure movements in two volcanoes within the East African Rift, Alutu and Corbetti, 250 kilometers south of Addis Ababa.
A large hammer drill, powered by three car batteries, was used to drill a hole into the hard rock for the antenna pin, which needed to be perfectly straight for the GPS antenna to record the satellite signals properly. The antenna was set on the pin and aligned and connected to the recorder, which collected a GPS signal from the satellites every 15 seconds. The equipment is connected to the battery and solar panels and waterproofed and protected with a fence.
Dr. Juliet Biggs, lecturer in the School of Earth Sciences at the University of Bristol, said Alutu and Corbetti had the biggest deformation signals. “This was surprising as they haven’t been studied very much. There’s no monitoring and no background information regarding historical eruptions.”
Dr. Juliet has used to satellites to study the chain of nearly 100 volcanoes that lies within the East African Rift zone. She found that in both 2004 and 2008, the ground around Alutu and Corbetti lifted by as much as 15 centimeters in a single year.
“Deformations such as these are typically attributed to magma accumulating and moving underground,” said Dr Juliet, “and are often interpreted as pre-eruptive activity. So, we’re very curious to find out what’s causing this unrest.”
Without monitoring, the risks for many vulnerable and often remote communities are unknown. Thousands of people live right on these volcanoes, farming the flat, fertile land within the years. The newly installed observatory provides a crucial service, including early warnings of seismic changes that may portend an impending eruption.
The data Biggs collected from these stations, and that collected from a network of seismic stations, also run by the University of Bristol, will help her interpret the deformations she is seeing from the satellite images. This information can then help the Ethiopian government to recognize the potential hazards associated with these volcanoes and plan accordingly. It could also benefit the geothermal industry, as drilling activities are expected to begin on both Alutu and Corbetti within the next year.