It’s mid-morning and smoke is rising through the thatched roof of the mud hut far below; coffee beans are being roasted. Matt stands perilously on the edge of a cliff, balancing as he drills into an outcropping of black, volcanic rock. He pauses to check whether the hole is big enough to fit the metal cylinder he has tucked into his back pocket. It’s not. He adjusts his hat against the Ethiopian sun, leaving prints of sweat and rock dust, and starts the roar of the hammer drill again.

The cliff is 250 kilometers (roughly 155 miles) south of Addis Ababa on the northern shore of Lake Awasa, on the rim of the Corbetti volcano crater. While Matt continues to drill, Juliet sits nearby, preparing equipment that she and the rest of the scientific team will set up here.

Curious villagers have gathered around, and the audience grows as farmers below weave their way up to the activity, leaving their livestock and loaded donkeys to graze the dry vegetation. Tulu — the only member of this four-person research team who speaks the local Oromo language — listens intently as the villagers tell him about the area’s troop of inquisitive baboons, who present a new challenge to the team and possibly their equipment.

This team of scientists from the U.K. and Ethiopia has just spent a week exploring every accessible outcropping of obsidian — a glass-like, volcanic rock — on two volcanoes located within the East African Rift: Alutu and Corbetti. The team is looking for sites to place ground-based GPS monitoring equipment that will measure movements in the Earth’s crust.

For the last few years, Dr. Juliet Biggs, lecturer at the University of Bristol in England, has used satellites to study the chain of nearly 100 volcanoes (including the famous Mount Kilimanjaro) that lies within the East African Rift Zone. She’s found that in both 2004 and 2008, the ground around Alutu and Corbetti lifted by as much as 15 centimeters (almost 6 inches) in a single year.

“These deformations — inflating and deflating of the surface — are typically attributed to the movement of magma below the surface,” she says, “and can be interpreted as a sign of unrest.” Though there are no records of these two volcanoes erupting, large craters and thick deposits of ash are indicative of an explosive past. Thousands of people live right on these volcanoes, farming the flat, fertile land within the craters. Yet there is no permanent monitoring equipment in place on either to provide advanced warning of an eruption (Juliet and her team only have resources to keep their equipment here for a year or two at most).

This is not uncommon. There are approximately 1,300 volcanoes worldwide that are known to have erupted over the last 10,000 years, but only 100 volcano observatories to engage in monitoring. Some of these use advanced technology to monitor multiple volcanoes, while others are manned by no more than a lone individual stationed in a remote hut.

This leaves a large portion of the world’s volcanoes unwatched. Although a number of them may well be dormant, others like Alutu and Corbetti may be showing signs of activity. Without monitoring, the risks for many vulnerable and often remote communities are unknown.

And an eruption affects more than those living on the volcano itself. For example, the 2010 eruption of Iceland’s Eyjafjallajökull resulted in the evacuation of hundreds of nearby residents, but the ash cloud it produced also left millions of travelers stranded in Europe and cost airlines an estimated US$1.7 billion in revenue.

The Icelandic Meteorological Office monitors Eyjafjallajökull and so was able to relay phone messages to the local residents, advising evacuation. However, in the case of unmonitored volcanoes worldwide, lack of advance warning might mean widespread devastation.

Juliet and her colleagues are keen to increase the number of monitored volcanoes by improving global satellite monitoring. By comparing two images taken at different times, Juliet measures changes in distance between the Earth’s surface and the satellite over a grid of data points. She can then calculate and visualize how the land is deforming over time.

Data collected from the equipment being installed on Alutu and Corbetti will help the scientists understand what’s causing the land to lift and subside. This information can then help the Ethiopian government to recognize the potential hazards associated with these volcanoes and plan accordingly. It will also inform industrial activity in the area, as deep drilling for geothermal energy production is expected to soon occur on both volcanoes. The data collected may not only help to target areas of high geothermal production but also provide insights into the potential effects of the drilling itself.

Satellites are used to remotely monitor erupting volcanoes, but apart from work by researchers like Juliet, they are not being used to look for pre-eruptive activity. Radar satellites typically have a life span of only a few years, so relying on them for a global monitoring system is impractical. The European Space Agency, however, is set to launch Sentinel-1 later this year — a satellite that will collect data from around the globe every few days for the next 20 years. This long-term commitment could allow Juliet and others in her field to develop the use of satellite imagery as a global monitoring tool.

In the meantime, the team has set up another GPS monitoring station. Nure, the local farmer who lives in the hut below, has agreed to watch the equipment for a fair fee. He and the other spectators have helped the team pile rocks over the equipment and surround it with a fence of thorny acacia branches. Whether this defense will prove stronger than the curiosity of the baboons, though, remains to be seen.