New 'Jerk' Seismic Method Predicted 92 Percent of Volcano Eruptions Over a Decade, Now Heading to Mount Etna
Researchers from IPGP and GFZ have validated a single-seismometer technique that detects nanometer-scale ground signals hours before eruptions, and plan to deploy it on Mount Etna in 2026 through the POS4dyke project.
A seismic detection technique that uses a single broadband seismometer to spot the faint ground motions preceding volcanic eruptions has been validated over more than a decade of real-time, automated operation at Piton de la Fournaise on the French island of La Reunion. The method, dubbed “Jerk,” correctly flagged 92 percent of the 24 eruptions that occurred between 2014 and 2023, with warning times ranging from minutes to 8.5 hours.
The research, published in Nature Communications by Dr. Francois Beauducel of the Institut de Physique du Globe de Paris (IPGP) and Dr. Philippe Jousset of the GFZ Helmholtz Centre for Geosciences in Potsdam, describes how the system detects extremely low-frequency transients in horizontal ground motion. These signals, measured in nanometers per second cubed, are generated by dynamic rock-fracturing processes as magma forces open pathways underground. The amplitudes involved are minuscule — on the order of a few nanometers per second cubed — yet they carry enough information to distinguish genuine pre-eruptive activity from background noise.
How the Method Works
The Jerk system operates as a fully automated module of the WebObs monitoring platform at the Observatoire Volcanologique du Piton de la Fournaise (OVPF-IPGP). It draws data from a single seismic station positioned roughly eight kilometers from the volcano’s summit. The software applies corrections for Earth tides and other environmental noise, then watches for impulse-like transitions in horizontal ground motion that exceed pre-established threshold values.
When a signal crosses the threshold, the system triggers an automatic alert. The first such alert came on June 20, 2014, arriving one hour and two minutes before an eruption began. Over the following nine years, the system continued to operate without human intervention, detecting pre-eruptive Jerk signals ahead of 22 of 24 eruptions.
Of the alerts that did not lead to eruptions, all 14 percent of false positives corresponded to confirmed magma intrusions — episodes where magma moved toward the surface but stopped short of breaking through. The researchers characterize these as “aborted eruptions” rather than genuine false alarms, since each represented real subsurface activity that warranted monitoring attention.
A Recent Test Case
The method faced a practical test during a seismic crisis at Piton de la Fournaise on December 5, 2025. Associated with low deformations and subtle gas anomalies, the event produced a small Jerk signal of just 0.1 nanometers per second cubed. That faint reading was enough to confirm that a magma intrusion had taken place, consistent with independent geochemical and geodetic observations.
“The great originality of this work lies in the fact that the Jerk method was tested and validated in real time in an automatic and unsupervised manner for more than 10 years, and not in post-processing of data,” Dr. Jousset said.
Expanding to Mount Etna
Having demonstrated the approach on an ocean-island basaltic volcano, the team now plans to test whether Jerk signals are detectable at a compositionally and structurally different target. The POS4dyke project will deploy a new network of broadband seismometers from the GIPP Geophysical Instrumental Pool of Potsdam around Mount Etna in Italy beginning in 2026, in collaboration with the Istituto Nazionale di Geofisica e Vulcanologia (INGV).
A companion effort, the SAFAtor project, will investigate whether fiber-optic sensing cables can complement the broadband seismometers, potentially offering denser spatial coverage of pre-eruptive ground deformation. Together, the two projects aim to determine whether the low-cost, single-instrument approach proven at Piton de la Fournaise can be generalized to other volcanic settings.
The appeal of the Jerk method lies in its simplicity. Many volcano observatories worldwide already operate broadband seismometers, meaning the technique could in principle be deployed through software updates rather than new hardware installations. Whether that promise holds for volcanoes with different magmatic plumbing systems is the question the Etna campaign is designed to answer.