Interpreting a volcano's 'bulges' and predicting the next explosive eruption

Geophysicist D. Sarah Stamps and her team tracked a short-lived surface bulge at Ol Doinyo Lengai in 2024 and, using numerical modeling, attributed it to about one million cubic meters of magma injected into an existing reservoir roughly 3 kilometers underground - roughly the volume of 400 Olympic swimming pools. That intrusion is modest, did not appear to migrate toward the crater, and is not itself cause for alarm, but it validates Virginia Tech’s early-stage monitoring and alert capabilities. The study, published in Frontiers in Earth Science (DOI 10.3389/feart.2026.1881885), demonstrates how sensitive ground measurements can resolve small but meaningful magma movements beneath an active volcano.

The team emphasizes eruption context and warning signs: Ol Doinyo Lengai alternates between effusive and explosive behavior with explosive events averaging every 10-15 years, so another explosive eruption is plausible within a human lifetime. Continuous ground-based monitoring since 2016 (six GNSS stations with ~1 mm precision, two broadband seismic stations, plus episodic benchmarks) gives a decade-plus record to link subsurface magma motions to surface signals. Concerning precursors would include a large earthquake (the last explosive event was preceded by a M5.9 quake), pronounced surface deformation, or upward migration of magma toward the vent - changes that would shorten the warning window and prompt community preparations.