Volcanoes send tiny warning signals before eruptions, and scientists are decoding them

The Jerk system, a single broadband seismometer tested at Piton de la Fournaise over a ten-year period, identified small ground 'jerk' signals and flagged about 92% of that volcano's eruptions minutes to hours before they occurred.

Predicting volcanic eruptions remains challenging because many key conditions inside a volcano are hard to observe. A new automated monitoring approach called Jerk uses one broadband seismometer to detect sudden ground movement linked to magmatic intrusions. The instrument was installed near Piton de la Fournaise in 2014 and was monitored over a decade, producing the dataset described in a December 2025 Nature Communications study. Researchers report that the system flagged early signals that preceded many eruptions, and they are working to refine the method and test it at other volcanoes. Key findings: - Jerk is a single, fully automated broadband seismometer system designed to identify early ground "jerk" signals associated with magmatic intrusion. - The device was installed about 8 kilometers from Piton de la Fournaise and recorded continuously from 2014 across a ten-year study period. - Over that period, the system identified signals that corresponded to about 92% of the volcano's eruptions, with alerts sent from minutes to eight hours beforehand. - The signal described as a "jerk" relates to rapid changes in ground acceleration and horizontal movement tied to rock fracturing as magma migrates. - Researchers note occasional false positives caused by nearby maintenance or human activity and aim to reduce those events. - The team plans to deploy Jerk-style instruments at other volcanoes, including Mount Etna, and to use multiple stations to better locate signal sources. Summary: The reported results indicate that a single, automated seismometer can record small ground signals linked to magmatic intrusions and that those signals matched most eruptions at Piton de la Fournaise during the study period. Next steps include improving automatic discrimination of false positives and expanding testing to other volcanic settings such as Mount Etna to assess whether similar signals appear elsewhere.