Science is a work in constant progress; Despite advances, humanity still struggles to fully explain many natural phenomena. That includes predicting volcanic eruptions. While extensive monitoring networks provide researchers with some precursors to eruptions, these systems remain imperfect.
But a new tracking system called “Jerk” could offer a simple and reliable solution to this problem. Described in December 2025. Nature Communications studio, Jerk is a unique broadband seismometer capable of automatically identifying very early signs of volcanic eruptions in real time, and is fully automated.
Typically, announcements about innovative technologies come before the product is released into the real world, and the conclusion is something like, “We think it should work the way we say it will work!” And even if the tool is tested, it’s rare for experiments to last for years, especially if that tool is meant to study extreme environments like a volcano.
Well, in some ways Jerk is none of these things. The team behind Jerk installed their tool on the Fournaise Python on the island of Reunion, France, in 2014, where it is still located today. The latest paper covers a 10-year study period, during which Jerk successfully predicted 92% of the volcano’s eruptions, sending alerts between minutes and eight hours in advance.
It couldn’t have been an easy feat. Then Gizmodo reached out to François Beauducel and Philippe Joussetgeophysicists who conceptualized, executed, and tested Jerk for over a decade. In this Q&A, Beauducel and Jousset, from the Institut de Physique du Globe de Paris in France and the Helmholtz Center for Geosciences in Germany, respectively, reflect on the various challenges and insights during their unique decade-long journey, and where things might go from here.
The following conversation has been lightly edited for grammar and clarity.
Gayoung Lee, Gizmodo: Generally speaking, why have we found it so difficult to predict volcanic eruptions or earthquakes?
François Beauducel: We have many observations of atmospheric conditions. So we can put all this data in a very complex model and make predictions that are not perfect, but efficient, in the short term. We do not have observation inside the volcano. That is the main reason. If we could measure everything (all the mechanical characteristics, the physical characteristics of the rocks, the magma chamber, and the shape of the tube from the fissure to the surface), we could probably make good predictions.
Philippe Jousset: Furthermore, it is not a measurement technique that allows us to understand what is happening. It’s not that there is an opening and then the magma (imagined as a fluid) comes out. It is more complex because magma is full of crystals, gas, liquid and water, whose behavior depends on the composition of the relative materials.
Gizmodo: Okay, so what is Jerk? How does the tool alleviate these challenges?
Beauducel: Currently, volcanic stations require (manual operations) by humans to integrate, synthesize and analyze all the observations, and then you can say: “We probably think an eruption is coming.” So this is very specialized work made possible by volcanologists based on geophysics and geochemistry.
The Jerk system is innovative because it is completely automatic. It can be implemented using a single station, over a relatively long distance. At the Piton de la Fournaise, Jerk settled about 8 kilometers (5 mi) from the volcano. The system detects early rock fracture during magma migration to the surface.
For most volcanoes, the definition of an eruption is magma coming to the surface. And to come to the surface, the magma needs to crack the rock or create a new fissure, and the opening produces a “shake.” The word used in the article is magmatic intrusion.
fair: If there is an intrusion, magma can reach the surface, making it, by definition, an eruption. But sometimes it gets stuck because the pull is not big enough.
Gizmodo: Then the intrusion “pushes” the magma towards the surface.
Beauducel: Yes. The word “moron” here refers to several things, but the first definition is mathematical; It is a derivative of the acceleration of the ground, as well as the brutal horizontal movement of the surface.
Gizmodo: And you tested this system in Piton de la Fournaise for ten years. That’s a long time. How were you able to keep going with this and also make sure that everything stayed consistent throughout the decade?
Beauducel: That is a very interesting question. First of all, the Piton de la Fournaise team is very small, about 15 people. But the observatory was installed about 50 years ago, so there are almost 50 years of recorded data. I created software specially designed to experiment with new signal processing and real-time data modeling about volcanoes. So we went to the observatory in April 2014 and it only took 10 days of field work to get the system operational.
As for why it took 10 years to validate it, the first reason was that we didn’t know what the “asshole” was. It wasn’t that we invented a new theory and tried to apply it. We had the signal and then we implemented it as a warning system. In the end we had 24 eruptions to validate (with the system). So that’s really the story; We took our time and discussed it a lot. We knew we were the only ones seeing this type of sign, so we weren’t in a hurry. And in fact, in 2023, the Piton de la Fournaise stopped erupting. This happens every 10 or 15 years at this volcano.
fair: Yes, it was like the volcano was happy to let us work, and once we finished (our analysis), it was done.
Gizmodo: Philippe, do you remember how your contribution to this project began?
fair: I remember exactly where and when we discussed this. That was in Indonesia. At that point, Jerk had been implemented for about 5 years, and the Piton de la Fournaise had an eruption when we were in Indonesia, and Francois said to me, “Oh, look, a ‘jerk’. There will be an eruption.” And I didn’t believe it. I said, “Yes, it’s working, but what is it?” Francois said that this signal was the seismometer channels that recorded the position of the mass and the speed (of the movement of the ground).
One of the projects I worked on while in France was at a site where a sudden collapse of material at a mine produced significant “tilts” in broadband seismometers installed near this site. And I saw that in this mass position on the volcano, there is something to discover with this signal.
Gizmodo: So Jerk is pretty good at predicting eruptions, at least for the Piton de la Fournaise. What’s in store for your team next?
Beauducel: At Piton La Fournaise, the next challenge is to improve the Jerk system. Sometimes we get false positives from station maintenance or someone walking nearby. Eventually we want to make it fully automatic and distinguish false positives from normal alarms.
fair: We would also like to measure these signals at other volcanoes, to see if similar signals exist elsewhere. Mount Etna(where we will implement this next), is the best place to do it because it is an active volcano; There are many eruptions with very small fractures that cannot be seen with conventional instruments (which Jerk could see).
The challenge is that we will deploy at or near the surface. We are going to dig holes as deep as possible to isolate the system from other noise sources. With multiple stations, we hope to locate where these small signals occur and if they are different compared to Piton de la Fournaise.
