ISTerre - Institut des Sciences de la Terre

Apér'ISTerre: Meet, Share and Discuss Science in Chambéry

Daniela Gutierrez — 2026-10-12T10:57:27Z

Join us for Apér'ISTerre, a weekly gathering to share the laboratory's research topics and encourage dialogue.

Every Tuesday, from 11:30 a.m. to 12 p.m., a member of the laboratory, a researcher, PhD student, professor emeritus or intern, presents one of their research topics for around 15 minutes. The presentation is followed by approximately 15 minutes of discussion and exchange with participants.

The goal? To explore the diversity of research carried out at ISTerre, share knowledge and encourage dialogue among laboratory members in a friendly and welcoming atmosphere, open to everyone.

Program

Practical Information

📅 When? Every Tuesday, from 11:30 a.m. to 12 p.m., with occasional exceptions.

📍 Where? In person, at the ISTerre site in Chambéry.

👥 Who can attend? All laboratory members are welcome!

Apér'ISTerre : un rendez-vous scientifique convivial à Chambéry

Daniela Gutierrez — 2026-10-09T16:33:16Z

Retrouvez les Apér'ISTerre, un rendez-vous hebdomadaire pour partager les sujets de recherche du laboratoire et susciter les discussions.

Chaque mardi, de 11h30 à 12h, une personne du laboratoire — chercheur, doctorant, professeur émérite ou stagiaire — présente l'un de ses sujets de recherche pendant une quinzaine de minutes. La présentation est suivie d'environ 15 minutes d'échanges avec les participants.

L'objectif ? Découvrir la diversité des recherches menées à ISTerre, partager les connaissances et favoriser les échanges entre les membres du laboratoire, dans une ambiance conviviale et accessible à toutes et à tous.

Programme

Informations pratiques

📅 Quand ? Tous les mardis, de 11h30 à 12h, sauf exception.

📍 Où ? En présentiel, sur le site d'ISTerre à Chambéry.

👥 Pour qui ? Tous les membres du laboratoire sont les bienvenus !

Deep Seismic Tremors in the 2025 Santorini Seismo‐Volcanic Crisis Highlight Magmatic Feeding from a Mid‐Crustal Reservoir

Daniela Gutierrez — 2026-10-09T15:33:07Z

The intense seismic swarm that took place in the Santorini‐Amorgos region in early 2025 was felt by local inhabitants and caused the declaration of a state of emergency at Santorini Island. At the same time, an intense debate emerged within the scientific community in early 2025 about whether this seismic crisis was tectonic or volcanic in origin.

Using advanced seismological tools that enable effective detection and location of seismic signals, we have created detailed catalogs not only of the earthquakes comprising the seismic swarm, but also of the continuous signals called seismic tremors that occurred simultaneously with the swarm.

The spatio‐temporal characteristics of these two catalogs confirmed the volcanic origin of the 2025 Santorini crisis, with the possible involvement of deep magmatic fluids near a mid‐crustal magma reservoir located a few kilometers southeast of Kolumbo volcano.

Two families of seismic tremor detected during the crisis: deep tremor (white text), and tremor related to the earthquake swarm (blue text).

Location of sources from the two tremor families: deep tremor (green dots) located in the vicinity of a mid-crustal melt reservoir (orange, from Autumn et al., 2025), and tremor (light blue dots) collocated with the earthquake swarm (dark blue dots).

The full study is published in: AGU journal

References :

Autumn, K. R., Hooft, E. E. & Toomey, D. R. Exploring mid-to-lower crustal magma plumbing of Santorini and Kolumbo volcanoes using PmP tomography. Geochem. Geophys. Geosyst. 26, e2025GC012170 (2025).

Isken, M. P., Karstens, J., Nomikou, P., Parks, M. M., Drouin, V., Rivalta, E. et al. Volcanic crisis reveals coupled magma system at Santorini and Kolumbo. Nature 645, 939–945 (2025).

Lomax, A., Anagnostou, V., Karakostas, V., Hicks, S. P. & Papadimitriou, E. The 2025 Santorini unrest unveiled: Rebounding magmatic dike intrusion with triggered seismicity. Science 390, eadz8538 (2025).

Scientific contacts:

Jean Soubestre – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Nikolai Shapiro – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Florent Brenguier – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Des trémors sismiques profonds observés lors de la crise sismo-volcanique de Santorin en 2025, mettent en évidence une alimentation magmatique provenant d'un réservoir situé à une profondeur intermédiaire dans la croûte

Daniela Gutierrez — 2026-10-09T15:28:24Z

La série intense de séismes qui s'est produite dans la région de Santorin-Amorgos au début de l'année 2025 a été ressentie par les habitants et a entraîné la proclamation de l'état d'urgence sur l'île de Santorin. Parallèlement, un vif débat a éclaté au sein de la communauté scientifique au début de l'année 2025 pour déterminer si cette crise sismique était d'origine tectonique ou volcanique.

À l'aide d'outils sismologiques avancés permettant une détection et une localisation efficaces des signaux sismiques, nous avons établi des catalogues détaillés non seulement des séismes composant cette crise sismique, mais également de signaux continus appelés « trémors sismiques » qui se sont produits simultanément à celle-ci.

Les caractéristiques spatio-temporelles de ces deux catalogues ont confirmé l'origine volcanique de la crise de Santorin de 2025, avec l'implication possible de fluides magmatiques profonds à proximité d'un réservoir magmatique situé à une profondeur intermédiaire dans la croûte, à quelques kilomètres au sud-est du volcan Kolumbo.

Localisation des sources des deux familles de trémor : trémor profond (points vert) localisé à proximité d'un réservoir magmatique situé à une profondeur intermédiaire dans la croûte (orange, d'après Autumn et al., 2025), et trémor (points bleu clair) co-localisé avec les séismes de l'essaim sismique (points bleu foncé).

Deux familles de trémor détectées lors de la crise : trémor profond (texte blanc), et trémor lié à l'essaim sismique (texte bleu).

L'étude complète est publiée dans : le journal AGU

Références :

Autumn, K. R., Hooft, E. E. & Toomey, D. R. Exploring mid-to-lower crustal magma plumbing of Santorini and Kolumbo volcanoes using PmP tomography. Geochem. Geophys. Geosyst. 26, e2025GC012170 (2025).

Isken, M. P., Karstens, J., Nomikou, P., Parks, M. M., Drouin, V., Rivalta, E. et al. Volcanic crisis reveals coupled magma system at Santorini and Kolumbo. Nature 645, 939–945 (2025).

Lomax, A., Anagnostou, V., Karakostas, V., Hicks, S. P. & Papadimitriou, E. The 2025 Santorini unrest unveiled : Rebounding magmatic dike intrusion with triggered seismicity. Science 390, eadz8538 (2025).

Contacts scientifiques :

Jean Soubestre – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Nikolai Shapiro – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Florent Brenguier – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Un nouveau MOOC pour comprendre et anticiper les risques naturels

Daniela Gutierrez — 2026-10-05T10:21:21Z

Volcans, glaciers, séismes, glissements de terrain… Comment surveiller et mieux comprendre les risques naturels? Que peuvent nous apprendre les satellites sur les processus qui façonnent notre planète ?

Le nouveau MOOC « Télédétection des risques naturels » (ORISAT) propose une introduction à l'utilisation des données satellitaires pour étudier et surveiller les risques naturels.

Pendant 7 semaines, des chercheurs guideront les participants à travers les différentes approches de la télédétection, de l'imagerie satellitaire et du traitement des données à la corrélation d'images, la photogrammétrie, l'interférométrie SAR et les séries temporelles. Le cours explorera également comment combiner ces méthodes pour étudier les séismes, les volcans, les mouvements de terrain et les glaciers, ainsi que le rôle croissant de l'intelligence artificielle et des données satellitaires dans les systèmes d'alerte précoce.

Aucune connaissance préalable n'est requise. Que vous soyez étudiant, chercheur ou simplement curieux de comprendre les risques naturels et l'observation de la Terre par satellite, ce MOOC est ouvert à tous.

Le MOOC en pratique

Durée : 7 semaines
Charge de travail : 1 à 2 heures par semaine
Langues : français, anglais et espagnol
Format : cours vidéo, transcriptions, sous-titres, quiz d'auto-évaluation et forum de discussion
Plateforme : France Université Numérique (FUN)
Début du cours : 5 octobre 2026
Clôture des inscriptions : 20 novembre 2026
Fin du cours : 27 novembre 2026

Équipe scientifique et pédagogique d'ISTerre

Virgine Pinel
Pascal Lacroix
Marie-Pierre Doin
Erwan Pathier
James Hollingsworth
Hugo Sanchez
Anne Socquet
Sophie Giffard
Léa Pousse

S'inscrire au MOOC

Le MOOC a été développé par 15 enseignants et chercheurs des laboratoires LISTIC, GET, ISTerre et IGE, avec le soutien de UGA, OSUG, IRD et ISDeform.

Les inscriptions sont ouvertes depuis le 29 juin 2026.

A new MOOC to understand and anticipate natural hazards

Daniela Gutierrez — 2026-10-05T10:17:26Z

Volcanoes, glaciers, earthquakes, landslides… How can we monitor and better understand natural hazards ? What can satellites tell us about the processes shaping our planet ?

The new “Remote Sensing of Natural Hazards” (ORISAT) MOOC offers an introduction to the use of satellite data to study and monitor natural hazards.

Over 7 weeks, researchers will guide participants through the latest approaches in remote sensing, from satellite imagery and data processing to image correlation, photogrammetry, SAR interferometry and time series. The course will also explore how these methods can be combined to study earthquakes, volcanoes, land movements and glaciers, as well as the growing role of Artificial Intelligence and satellite data in early warning systems.

No prior knowledge is required. Whether you are a student, researcher or simply curious about natural hazards and satellite-based Earth observation, this MOOC is open to all.

The MOOC in practice

Duration : 7 weeks
Workload : 1–2 hours per week
Languages : French, English and Spanish
Format : Video courses, transcripts, subtitles, self-assessment quizzes and discussion forum
Platform : France Université Numérique (FUN)
Course start : 5 October 2026
Registration closes : 20 November 2026
Course ends : 27 November 2026

ISTerre Scientific and teaching team

Virgine Pinel
Pascal Lacroix
Marie-Pierre Doin
Erwan Pathier
James Hollingsworth
Hugo Sanchez
Anne Socquet
Sophie Giffard
Léa Pousse

Register here

The MOOC has been developed by 15 teachers and researchers from LISTIC, GET, ISTerre and IGE, with the support of UGA, OSUG, IRD and ISDeform.

Registration is open from 29 June 2026.

Game "Riskocity"

Daniela Gutierrez — 2026-10-01T16:03:00Z

"Riskocity" is a serious game designed and created by the Pacte and ISTerre laboratories as part of the Fête de la Science. Suitable for students from middle school onwards, the game introduces the concept of “major risks” in a fun and engaging way.

What is a major risk? It is the possibility that a natural or human-induced event (caused by human presence or activity) may occur and that its effects could threaten the safety of citizens and cause varying degrees of damage.

While major risks are a central concern for the effective management of a city, it is equally important for citizens to be aware of the major risks present in cities and villages and to know how to respond to and protect themselves from them.

The Riskocity game was designed to raise players' awareness of the different major risks that may affect a municipality and to help them learn where to find reliable information and resources on the subject.

The aim of the game

A new mayor has just been elected in Riskocity! Taking her new role very seriously, she would like to learn more about the city and the risks that threaten the safety of its residents. To do so, the mayor calls on an investigator to identify the city's potential hazards.

From the volcano to the ski resort and the Earth sciences laboratory, all these locations must be carefully investigated to uncover what lies within them…

So step into the shoes of a detective and conduct your investigation among the city's different stakeholders to draw up a list of the risks threatening Riskocity!

How to play

The game is available every year throughout the Fête de la Science on the respective websites of the two laboratories.

For more information or to access the game outside the event period, please contact daniela.gutierrez univ-grenoble-alpes.fr.

David Bercovici at ISTerre: Seminar and Round Table

Daniela Gutierrez — 2026-10-01T15:26:39Z

ISTerre welcomes David Bercovici, Professor at Yale University, member of the American Academy of Sciences, and co-founder of the Yale Center for Natural Carbon Capture, for a day dedicated to Earth dynamics and climate challenges.

Throughout his career, David Bercovici has worked on various aspects of geophysics, including mantle dynamics, rock rheology, and the processes underlying plate tectonics. He has also played an active role in advancing research on climate-related challenges and natural carbon capture.

@ Pr David Bercovici

11h00 — Seminar

The emergence of proto-plate boundaries from lithospheric drips with grain-damage

14h00 — Round table

Natural carbon capture and other climate-related topics

David Bercovici will also lead a round table dedicated to natural carbon capture and current climate-related challenges.

Co-founder of the Yale Center for Natural Carbon Capture, he will share his experience and discuss with researchers from ISTerre and other laboratories the challenges and research opportunities related to climate and carbon capture.

More info:

📍 Location : ISTerre, Amphithéâtre Killian

📅 Date : Wednesday, 7 October 2026 — 11h00 and 14h00

David Bercovici à ISTerre : séminaire et table ronde

Daniela Gutierrez — 2026-10-01T15:21:55Z

ISTerre accueille David Bercovici, Professeur à Yale University, membre de l'Académie des Sciences Américaine, et co-fondateur du Yale Center for Natural Carbon Capture , pour une journée consacrée à la dynamique de la Terre et aux enjeux climatiques.

Au cours de sa carrière, David Bercovici a travaillé sur de nombreux aspects de la géophysique, notamment la dynamique du manteau, la rhéologie des roches et les processus à l'origine de la tectonique des plaques. Il a également joué un rôle important dans le développement de recherches sur les enjeux climatiques et la capture naturelle du carbone.

@ Pr David Bercovici

11h00 — Séminaire

The emergence of proto-plate boundaries from lithospheric drips with grain-damage

14h00 — Table ronde

Natural carbon capture and other climate-related topics

David Bercovici animera également une table ronde consacrée à la capture naturelle du carbone et aux enjeux actuels liés au climat.

Co-fondateur du Yale Center for Natural Carbon Capture, il partagera son expérience et échangera avec les chercheurs d'ISTerre et des autres laboratoires sur les défis et les perspectives de recherche autour du climat et de la capture du carbone.

Plus d'infos

📍 Lieu : ISTerre, Amphithéâtre Killian

📅 Date : Mercredi 7 octobre 2026 — 11h00 et 14h00

Assessing the hazard of unstable rock blocks using seismic noise

Daniela Gutierrez — 2026-10-01T13:05:23Z

Robust estimation of rock mass volume is a key challenge for rockfall hazard assessment. However, this estimation remains particularly difficult due to the irregular geometry of blocks, the heterogeneity of material mechanical properties, and the poorly constrained boundary conditions, particularly at depth.

Fig. 1. Numerical simulation of rock-block resonance frequency as a function of block geometry and boundary conditions. The left column (a, c, e) shows a slender block (5 × 5 × 20 m) and the right column (b, d, f) a thick block (10 × 10 × 10 m). Panels (a, b) show a fixed base, (c, d) a block resting on a softer layer, and (e, f) a block embedded 10 m into the layer. Each panel shows the fundamental resonance frequency f₀ and normalized displacement. Adapted from [Bottelin et al., 2026b].

Fig. 3. Seismological measurements at the top of the column during drilling. (a) Recorded acceleration and strain proxy εproxy. (b) Power spectrum showing a decrease in the fundamental resonance frequency f₀ from 9.0 Hz outside drilling to 8.5 Hz during drilling. (c) Spectrogram highlighting the drops in f₀ at the onset of drilling and its recovery when vibrations cease. Adapted from [Bottelin et al., 2026b].

A recently proposed approach in the literature [Pazzi et al., 2025] consists of studying the fundamental natural frequency of rock blocks — estimated, for example, from a horizontal-to-vertical spectral ratio — and relating it to their volume using a chart derived from numerical simulations of parallelepipedal blocks fixed at their base [Pazzi et al., 2025]. However, Bottelin et al. [2026b] have shown that several limitations can affect the robustness of volume estimates based on the fundamental natural frequency, notably: (i) the representativeness of numerical models with respect to actual site conditions, (ii) the quality and processing of geophysical data, and (iii) the methodological assumptions and validation procedures used. These limitations must be carefully taken into account when interpreting the results in order to rigorously estimate the volume of rock masses from their fundamental resonance frequency.

In a second study, Bottelin et al. [2026a] investigate, through in situ seismological measurements, the evolution of the resonance frequency of an unstable rock column (Fig. 2). These measurements were performed during drilling operations carried out to reinforce the column using rock bolts, revealing nonlinear dynamics that provide insights into the internal cracking of rock structures.

Analysis of the measurements (Fig. 3) highlights the rapid nonlinear dynamics (anomalous nonlinear fast dynamics) observed at the beginning of drilling, as well as a clear correlation between the acceleration at the top of the column and decreases in resonance frequency, of the order of a few percent. Slow dynamics were also observed, manifested by a reproducible recovery of the fundamental resonance frequency after drilling was stopped. This recovery was also observed following seismic shaking generated by regional earthquakes. The magnitude of the nonlinear elastic effects observed in situ exceeds those measured in laboratory experiments on intact rock, revealing extensive, multiscale cracking within the studied rock column. These results show that passive seismic surveys conducted during periods of significant vibration can be used to probe material nonlinearity at the geophysical scale. This approach could have potential applications in geotechnical engineering and civil engineering, as well as in monitoring internal cracking within rock structures.

Fig. 2. View of an unstable 760 m³ limestone column undergoing reinforcement works, showing the location of the seismological sensor at the top of the column (S). The reinforcing rock bolts (5 to 12 m long) are shown as white dots topped with crosses. Adapted from [Bottelin et al., 2026a].

The full study is published in: NATURE

References :

Bottelin, P., Baillet, L., Larose, E., Guillemot, A. & Johnson, P. A. Nonlinear mesoscopic elasticity revealed by passive seismic monitoring of a rock column during drilling operations. J. Acoust. Soc. Am. 159, 2844–2856 (2026).

Bottelin, P., Baillet, L. & Larose, E. On the use of seismic noise studies for landslide rock block hazard assessment. Commun. Earth Environ. 7, 769 (2026).

Pazzi, V., Fornasari, S. F., Devoto, S., Costa, G. & Forte, E. Fast estimation of landslide blocks' volume from seismic noise measurements. Commun. Earth Environ. (2025).

Scientific contacts :

Pierre Bottelin – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Laurent Baillet – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France

Eric Larose – ISTerre, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. Gustave Eiffel, Grenoble, France