🌋 A new method to predict a volcanic eruption in time

Predicting a volcanic eruption in time to warn authorities and populations remains a major challenge on a global scale.

In a study published in the journal Nature Communications, researchers and engineers from the Institut de Physique du Globe de Paris (IPGP) and the GFZ Helmholtz Centre for Geosciences propose a new detection method, called "Jerk", capable of identifying very early precursor signals of volcanic eruptions in real time from a single seismological instrument.


The "Jerk" method allows for the real-time detection of extremely subtle ground movements related to deep magma injections. These signals, called Jerk signals, manifest as very low-frequency transients observed in the horizontal movements of the ground, both in acceleration and tilt. The authors show they are likely generated by dynamic rock fracturing processes preceding an eruption. With an amplitude on the order of a few nanometers per second cubed (nm/s³), these signals can be detected using a single very broadband seismometer, provided specific processing is applied, notably including correction for Earth tides.

In April 2014, the tool was implemented at the IPGP's Piton de la Fournaise Volcanological Observatory (OVPF-IPGP, Réunion Island) as a fully automated module of the WebObs system, using data from a seismological station of the global Geoscope network located about 5 miles (8 km) from the volcano's summit (Rivière de l'Est).

On June 20, 2014, a first alert was sent 1 hour and 2 minutes before the eruption started. For over 10 years, this system for detecting and analyzing Jerk signals has operated continuously, 24/7, allowing for automatic alerts to be issued for 92% of the 24 eruptions that occurred between 2014 and 2023. Alert times ranged from a few minutes to 8.5 hours before magma reached the surface. The method was also tested on data from 24 past eruptions between 1998 and 2010, showing that the Jerk alert works systematically.

The great originality of this work lies in the fact that the Jerk method was tested and validated in real time automatically and unsupervised for over 10 years, unlike the vast majority of published studies on eruptive precursors, which are based on post-processing of data and retrospective analysis.

The system has, however, occasionally produced "false positives" — clear alerts not followed by an eruption — all of which turned out to be real magma intrusions or "failed eruptions", an interpretation corroborated by all other observables such as seismicity, deformation, and volcanic gas analyses. Beyond the effectiveness of the Jerk alert for eruptions, the tool thus proves to be a perfect and unambiguous detector of magmatic intrusions.

During the last seismic crisis at Piton de la Fournaise on December 5, 2025, associated with minor deformation and gas anomalies, a small Jerk signal was emitted (only 0.1 nm/s³), confirming that a magma intrusion had indeed occurred.

As Piton de la Fournaise is a highly instrumented and monitored laboratory volcano, the Jerk tool is used by the OVPF-IPGP as a complementary indicator to the many precursor signs from other observables, helping to confirm the reality of a magmatic intrusion.

On other poorly instrumented volcanoes, the Jerk tool could be used as a simple and effective method for early warning of volcanic eruptions. Much remains to be done, particularly testing the method on other active volcanoes, starting with Mount Etna (Italy) where a project involving the GIPP (Geophysical Instrumental Pool of Potsdam) aiming to detect the Jerk signal with a new network of seismometers is set to begin in 2026, in collaboration with the INGV (Italy).