LisAlps - Explorer la lithosphère alpine en 3D par inversion de formes d'ondes des données télésismiques AlpArray - ANR 2021
Probing the 3D Alpine lithosphere by Full Waveform Inversion of the AlpArray teleseismic data
NILAFAR - Quantifier les fluctuations hydrologiques, documenter leurs conséquences sur les communautés humaines passées - ANR PRC 2021
The NILe and AFAR regions: hydrologic changes and impact on human adaptation in the last 20,000 years
EARLI - Détection de signaux sismiques précoces en utilisant l'intelligence artificielle - ERC 2021
Detection od Early seismic signal using ARtificial Intelligence
WIND - Inversion de formes d'ondes - Consortium Pétrolier 2020
Waveform Inversion of Node Data
S5 - Séismes Lents & Essaims Sismiques - ANR 2019
Synchronous Slow Slip & Seismic Swarm
MARACAS - Les terrasses marines comme proxy pour l’appréhension de l’aléa sismique - ANR JC 2018
MARine terraces alonf the northern Andean Coast as a proxy for seismic hazard ASsessment
All the labs former projects
The main objective is to improve our understanding of the role of fluids on the rupture of earthquake faults. To date, few data are available to study the couplings between fluids, fault slip and seismicity. In this project, we propose to develop a new in-situ approach based on the hydraulic stimulation of a small fault segment (10 m) under controlled experimental conditions.
The fluid injections will produce small fault slip (few millimeters) and will be monitored with a dense network of sensors, including pressuremeters, strainmeters, seismometers and electrical imaging. This original experiment will be conduct at 300 m-depth at the Low Noise Underground Laboratory of Rustrel in France.
Subducting slabs carry water into the mantle and are a major gateway in the global geochemical water cycle. Fluid transport and release can be constrained with seismological data. Here we use joint active-source/local-earthquake seismic tomography to derive unprecedented constraints on multi-stage fluid release from subducting slow-spread oceanic lithosphere.
We image the low P-wave velocity crustal layer on the slab top and show that it disappears beneath 60–100 km depth, marking the depth of dehydration metamorphism and eclogitization. Clustering of seismicity at 120–160 km depth suggests that the slab’s mantle dehydrates beneath the volcanic arc, and may be the main source of fluids triggering arc magma generation. Lateral variations in seismic properties on the slab surface suggest that serpentinized peridotite exhumed in tectonized slow-spread crust near fracture zones may increase water transport to sub-arc depths.
This results in heterogeneous water release and directly impacts earthquakes generation and mantle wedge dynamics.
A fundamental question raised by the Tohoku-Oki earthquake is to know whether seismic rupture of giant earthquakes can be anticipated either in time (months, days or hours before the rupture), location and/or magnitude, and how, within 10 minutes after the quake, the amplitude of a tsunami can be estimated before it reaches the coast. Over the last decades, scientists have tried to address this question through different approaches, but mainly by (1) trying to isolate potential precursory signals or (2) improving our knowledge of the seismic cycle (how stress and strain balance over several earthquakes) to understand the physical parameters that control the size and location of those large earthquakes. More recently, a third more practical approach was developed called (3) early-warning which takes advantage of the slower propagation speed of seismic or tsunami waves compared to our communication networks to provide at least a few seconds or minutes to anticipate the approaching waves and gauge the threat they represent.