A5086653786- earthquake and tectonic studies
- Seismology and Earthquake Studies
- Earthquake Detection and Analysis
- Seismic Waves and Analysis
- Geophysics and Sensor Technology
- Geological and Geochemical Analysis
- Seismic Imaging and Inversion Techniques
- High-pressure geophysics and materials
- Geological and Geophysical Studies
- Advanced Fiber Optic Sensors
- GNSS positioning and interference
- Underwater Acoustics Research
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Geological and Tectonic Studies in Latin America
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Landslides and related hazards
- Geological and Geophysical Studies Worldwide
- Reservoir Engineering and Simulation Methods
- Underwater Vehicles and Communication Systems
- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Structural Health Monitoring Techniques
- Speech and Audio Processing
- Traffic Prediction and Management Techniques
Centre National de la Recherche Scientifique
2015-2024
Observatoire de la Côte d’Azur
2014-2024
Université Côte d'Azur
2014-2024
Institut de Recherche pour le Développement
2015-2024
Géoazur
2015-2024
Fondation Sophia Antipolis
2024
California Institute of Technology
2008-2013
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2006-2008
CEA DAM Île-de-France
2006-2007
Geophysical observations from the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki, Japan earthquake allow exploration of a rare large event along subduction megathrust. Models for this indicate that distribution coseismic fault slip exceeded 50 meters in places. Sources high-frequency seismic waves delineate edges deepest portions and do not simply correlate with locations peak slip. Relative to M(w) 8.8 2010 Maule, Chile earthquake, Tohoku-Oki was deficient radiation--a difference we attribute...
Abstract We determine coseismic and the first-month postseismic deformation associated with Sumatra–Andaman earthquake of 26 December 2004 from near- field Global Positioning System (gps) surveys in northwestern Sumatra along Nicobar-Andaman islands, continuous campaign gps measurements Thailand Malaysia, situ remotely sensed observations vertical motion coral reefs. The model shows that Sunda subduction megathrust ruptured over a distance about 1500 km width less than 150 km, releasing...
Abstract Two thirds of the surface our planet are covered by water and still poorly instrumented, which has prevented earth science community from addressing numerous key scientific questions. The potential to leverage existing fiber optic seafloor telecom cables that criss-cross oceans, using them as dense arrays seismo-acoustic sensors, remains be evaluated. Here, we report Distributed Acoustic Sensing measurements on a 41.5 km-long cable is deployed offshore Toulon, France. Our...
Abstract The novel technique of distributed acoustic sensing (DAS) holds great potential for underwater seismology by transforming standard telecommunication cables, such as those currently traversing various regions the world’s oceans, into dense arrays seismo‐acoustic sensors. To harness these measurements seismic monitoring, ability to record transient ground deformations is investigated analyzing ambient noise, earthquakes, and their associated phase velocities, on DAS records from three...
Earthquake early warning (EEW) systems provide seconds to tens of time before potentially-damaging ground motions are felt. For optimal times, seismic sensors should be installed as close possible expected earthquake sources. However, while the most hazardous earthquakes on Earth occur underwater, seismological stations located on-land; precious may go by these detected. In this work, we harness available optical fiber infrastructure for EEW using novel approach distributed acoustic sensing...
Abstract Observations of coseismic and postseismic deformation associated with the 2010 Mw = 8.8 Maule earthquake in south‐central Chile provide constraints on spatial heterogeneities frictional properties a major subduction megathrust how they have influenced seismic rupture effects. We find that bulk slip occurs within single elongated patch approximately 460 km long 100 wide between depths 15 40 km. infer three patches afterslip: one extends northward along strike downdip 60 depth; other...
The 2004 Sumatra-Andaman and 2011 Tohoku-Oki earthquakes highlighted gaps in our understanding of mega-earthquake rupture processes the factors controlling their global distribution: A fast convergence rate young buoyant lithosphere are not required to produce mega-earthquakes. We calculated curvature along major subduction zones world, showing that mega-earthquakes preferentially flat (low-curvature) interfaces. simplified analytic model demonstrates heterogeneity shear strength increases...
The Mw 7.9 2008 Wenchuan earthquake ruptured about 280 km of faults in the Longmen Shan Sichuan province, China, at eastern edge Tibetan Plateau. We use teleseismic waveforms with geodetic data from Global Positioning System, synthetic aperture radar interferometry and image amplitude correlation to produce a source model this earthquake. describes evolution fault slip during constrains spatial distribution seismic constrain mostly time slip. find that started largely thrust motion on an...
We present a fully Bayesian inversion of kinematic rupture parameters for the 2011 Mw9 Tohoku-oki, Japan earthquake. Albeit computationally expensive, this approach to source modelling has advantage producing an ensemble slip models that are consistent with physical priori constraints, realistic data uncertainties, and but simplistic uncertainties in physics forward model, all without being biased by non-physical regularization constraints. Combining 1 Hz GPS, static GPS offsets, seafloor...
The ill-posed nature of earthquake source estimation derives from several factors including the quality and quantity available observations fidelity our forward theory. Observational errors are usually accounted for in inversion process. Epistemic errors, which stem simplified description problem, rarely dealt with despite their potential to bias estimate a model. In this study, we explore impact uncertainties related choice fault geometry problems. structure is generally reduced set...
Distributed acoustic sensing (DAS) is a recent instrumental approach allowing the conversion of fiber-optic cables into dense arrays sensors. This technology attractive in marine environments where instrumentation difficult to implement. A promising application monitoring environmental and anthropic noise, leveraging existing telecommunication on seafloor. We assess ability DAS monitor such noise using 41.5 km-long cable offshore Toulon, France, focusing known localized source. analyze...
Fiber-optic distributed acoustic sensing (DAS) is an emerging technology for vibration measurements with numerous applications in seismic signal analysis, including microseismicity detection, ambient noise tomography, earthquake source characterization, and active seismology. Using laser-pulse techniques, DAS turns (commercial) fiber-optic cables into arrays a spatial sampling density of the order meters time rate up to one thousand Hertz. The versatility enables dense instrumentation...
We use Interferometric Synthetic Aperture Radar, teleseismic body waves, tsunami waveforms recorded by tsunameters, field observations of coastal uplift, subsidence, and runup to develop test a refined model the spatiotemporal history slip during M w 8.0 Pisco earthquake 15 August 2007. Our preferred solution shows two distinct patches high slip. One patch is located near epicenter while another larger ruptured 60 km further south, at latitude Paracas peninsula. Slip on second started s...
It has previously been suggested that ionospheric perturbations triggered by large dip‐slip earthquakes might offer additional source parameter information compared to the gathered from land observations. Based on 3D modeling of GPS‐ and GLONASS‐derived total electron content signals recorded during 2011 Van earthquake (thrust, intra‐plate event, M w = 7.1, Turkey), we confirm coseismic do contain important about source, namely its slip mode. Moreover, show part signal (initial polarity...
Abstract The 11 March 2011 M w 9.0 Tohoku‐Oki earthquake was recorded by an exceptionally large amount of diverse data offering a unique opportunity to investigate the details this major megathrust rupture. Many studies have taken advantage very dense Japanese onland strong motion, broadband, and continuous GPS networks in sense. But resolution tests variability proposed solutions highlighted difficulty uniquely resolve slip distribution from these networks, relatively distant source region,...
Abstract After large earthquakes, parts of the fault continue to slip for days months during afterslip phase, a behaviour documented many earthquakes. Yet, little is known about early stage, i.e., from minutes hours after mainshock. Its detailed study requires continuous high-rate position time series close fault, and advanced signal processing accurately extract surface displacements. Here, we use refined kinematic precise point positioning document postseismic deformation three earthquakes...
Abstract. The use of distributed acoustic sensing (DAS) presents unique advantages for earthquake monitoring compared with standard seismic networks: spatially dense measurements adapted harsh environments and designed remote operation. However, the ability to determine source parameters using DAS is yet be fully established. In particular, resolving magnitude stress drop a fundamental objective early warning. To apply existing methods parameter estimation signals, they must first converted...
Distributed Acoustic Sensing (DAS) is a novel vibration sensing technology that can be employed to detect vehicles and analyse traffic flows using existing telecommunication cables. DAS therefore has great potential in future "smart city" developments, such as real-time incident detection. Though previous studies have considered vehicle detection under relatively light conditions, order for feasible real-world scenarios, algorithms need also perform robustly wide range of conditions. In this...
SUMMARY Distributed acoustic sensing (DAS) enables data acquisition for underwater Earth Science with unprecedented spatial resolution. Submarine fibre optic cables traverse sea bottom features that can lead to suspended or decoupled cable portions, and are exposed the ocean dynamics high rates of marine erosion sediment deposition, which may induce temporal variations cable’s mechanical coupling floor. Although these spatio-temporal fluctuations affect quality recorded by DAS, determine...