In 2024 , D. Sarah Stamps' team detected and tracked a short-lived bulge in the land around a volcano in Tanzania. In a paper published Sep. 18 , Stamps identified the cause of the uplift: a million cubic meters of magma pouring into an existing magma reservoir about 1.8 miles underground.
Stamps said the amount of magma is modest and not a cause for concern. But the finding demonstrates the effectiveness of Virginia Tech's early-stage alert system for volcanic activity.
Stamps explained the research, which was published in Frontiers in Earth Science in September 2026 .
What question is your research is trying to answer?
"This particular volcano, Ol Doinyo Lengai, is very active. A lava lake is currently bubbling and erupting effusively. We're most concerned with trying to figure out when the volcano is going to erupt explosively so that the people living in the area have ample time to prepare and respond to any decisions made by the Tanzania Geological Survey about evacuations."
Are we due for an explosive eruption?
"On average, there's an explosive eruption every 10 to 15 years. We do expect one within our lifetime, and we hope that our monitoring and modeling efforts will be worthwhile."
What are we seeing now?
"With as much certainty as we can get from numerical modeling, we found that the signal was due to an influx of magma into an already existing magma reservoir about 3 kilometers underground."
How much magma?
"The volume of the magma intrusion is about a million cubic meters. You could think of that as 400 Olympic-size swimming pools, which is a modest amount."
Is there cause for concern?
"The intrusion we're presenting in this paper is not of huge concern. There's a little more magma being injected into a system that we know exists, but the detected magma does not appear to be moving closer to the crater."
What would indicate a cause for concern?
"The last time it erupted explosively, there was a magnitude 5.9 earthquake first. I would be more concerned if there was a significant earthquake, and then we started to monitor observable surface deformation changes. Also, if we observe the magma moving from a deeper to a shallower location over time, that suggests the magma is moving up the volcanic vent. That would be concerning."
If you observed these concerning indicators, how much time would we have before an explosive eruption?
"Some volcanoes erupt explosively each time they erupt. Ol Doinyo Lengai alternates between erupting effusively and explosively. Part of the reason we're continuing to monitor it is to figure out this particular volcano's time delay."
How are you monitoring Ol Doinyo Lengai?
"In 2016, we installed six Global Navigation Satellite System instruments on the ground. They track the horizontal and vertical motions of the surface to within 1 millimeter. We also have two broadband seismic stations to detect earthquake activity. Plus, we supplement the continuous network with episodic benchmark measurements."
Are other teams monitoring this volcano?
"There are some satellite-based observations, like through NASA, but our team is currently the only one doing ground-based continuous GNSS and consistent ground-based seismic monitoring."
How can this work help nearby communities prepare for the 'big one'?
"We've now collected over a decade of observations. We have a better understanding of what magma movements underground match what we observe over this time period. This work can help us better understand when the volcano is getting closer to an explosive eruption based on what we're observing at the surface."
Original study : DOI 10.3389/feart.2026.1881885
