Séminaire ISTerre

Satellite-based and in-situ methodologies: application and signal extraction for the detection of landslide precursors.

mercredi 22 juin 2022 - 10h00
Benedetta Dini - ISTerre (séminaire post-doc)
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One of the major open questions in the domain of landslide hazard assessment and prediction is related to the timely and accurate detection of precursors, key indicators that precede failure or phases of large accelerations. In the last few decades, the increasing availability of satellite-based SAR imagery, characterised by large coverages and increasing temporal sampling, has allowed scientists to use InSAR techniques exploiting phase difference between successive images to identify previously unknown instabilities over inaccessible areas, to characterise gravitational phenomena and, in some cases, to accurately quantify displacements. However, the full potential of satellite based InSAR has not yet been realised for monitoring slope movements, owing to signal loss and a decrease in resolution caused by high noise levels due to vegetation, by high phase gradients due to large displacements over restricted areas, by unfavourable orientation and by the limitations of unwrapping procedures used to convert the direct measurement (radians) into displacements (mm). In addition, the incipient stages of deformation are rarely detected because they commonly develop over areas equivalent to a few pixels, challenging signal extraction with current available resolution. Key signals relying on the unwrapped phase as well as interferometric coherence are still relatively underused for landslide applications. Thus, there is the need to develop high resolution, ad hoc tools dedicated to the extraction of localised signal to complement the ever-growing large scale processing platforms. In addition to the InSAR-based methodology, I will also show the latest development achieved with bespoke, low-cost, in-situ sensors that combine accelerometer and gyroscope to measure small angular variations from rotational movements and subtle accelerations associated with ground movements. A first version of the sensors has been successfully deployed in Nepal, and an improved version is currently being tested at the Harmalière landslide. Crucial advantages over other in-situ methods are the relatively low cost, allowing long-term monitoring and dense networks; the high sensitivity to small surface rotations; the ability to activate on movement thresholds and real-time data transmission.

Equipe organisatrice : Organisation labo

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

“Minimalist seismology”: studying earthquakes with sparse instrumentation

jeudi 17 septembre 2026 - 11h00

Mathieu Causse - ISTerre

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Stable‑to‑dynamic expansion of fault slipping area through fluid injection observed in laboratory experiments using a sub‑meter scale specimen

vendredi 18 septembre 2026 - 14h00

Takatoshi Ito  - Université de Tohoku, Japan

Equipe organisatrice : Mécanique des failles

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Tectonics, Mantle Dynamics and Coupled Lithosphere-Mantle-Core Evolution of Earth and Other Rocky Worlds

jeudi 24 septembre 2026 - 11h00

Paul Tackley - ETH Zurich

Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Tectonics, Mantle Dynamics and Coupled Lithosphere-Mantle-Core Evolution of Earth and Other Rocky Worlds

jeudi 24 septembre 2026 - 11h00

Paul Tackley - ETH Zurich

Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Apport des expériences analogiques pour la modélisation et le suivi en temps réel de la propagation du magma en profondeur : Exemple du Rift Est Africain

jeudi 1er octobre 2026 - 11h00

Virginie Pinel - ISTerre

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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A t-on encore besoin de plaques pour expliquer la tectonique de la vallée du Rhône et des Alpes Occidentales ?

vendredi 2 octobre 2026 - 11h00

philippe VERNANT - Geosciences Montpellier

Equipe organisatrice : Tectonique active et sismicité

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 2 octobre 2026 - 14h00

Hugo Boulze - 

Equipe organisatrice : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 9 octobre 2026 - 11h00

Eric Beaucé - ISTerre

Equipe organisatrice : Cycle sismique et déformations transitoires

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 20 novembre 2026 - 11h00

Farzaneh Mohammadi - ENS Paris

Equipe organisatrice : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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