Séminaire ISTerre

Tracking Tremor & Tremor-like Signals in California

vendredi 27 novembre 2020 - 11h00
Asaf Inbal  - Tel Aviv University, Israel
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Tectonic tremors form a class of tectonic events associated with emergent, long‐duration, low‐amplitude seismic signals whose characteristics are distinct from regular earthquakes, or from the harmonic tremor observed near volcanos. They are sometimes described as resulting from a sequence of Low-Frequency Earthquakes (LFEs), which are essentially short-duration events whose high-frequency content is depleted relative to regular earthquakes of the same size. Efforts for identifying and determining tremor locations are complicated by the fact that tremor signals are similar in many respects to those generated by anthropogenic sources such as vehicle traffic, machinery, or wind farms. This issue may be addressed by using dense seismic array analysis. Due to their configuration (sensor spacing<100 m, aperture 1-10 km), dense arrays can effectively increase the signal-to-noise ratio, and filter low-incidence surface waves. The arrays are therefore capable of detecting low amplitude tremor signals in the 1 to 10 Hz frequency range, even in noisy environments. In the first part of the talk I will discuss array-based methods for discriminating tremor from man-made noise. I will point to the weaknesses and strengths of conventional tremor detection techniques, and discuss the implications for earthquake detection in noisy urban environments. In the second part I will present results from a short-term deployment of a dense array near the Cholame section of the San Andreas Fault. The experiment captured an unusually large tectonic transient that occurred on August 2018, during which tremor was observed to propagate along the Cholame and Parkfield sections. I will discuss the tremor migration patterns resolved by Cholame arrays and the regional network, the relation between tremor and LFE activity, and the frequency-dependent features of the tremor source.

Equipe organisatrice : Ondes et structures

Séminaire uniquement en visio

Informations de visio :

Sans réponse

“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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