Biography
François Lavoué is a postdoctoral researcher in the iCRAG Geophysics platform. His research interests concern the geophysical imaging of the Earth’s subsurface, using in particular waveform inversions. François graduated from University of Grenoble (France) in 2014 with a PhD on full waveform inversion of ground-penetrating radar data. He then visited Colorado School of Mines (USA) to work on image-guided inversion of electrical data before joining iCRAG in 2016. Within iCRAG, François is working with Dr Sergei Lebedev on multiscale seismic waveform inversions involving sparse parameterisations. His developments target applications at various scales, from sedimentary basins to lithospheric imaging.
Much like medical imaging, geophysical imaging enables us to see the unseen, unraveling the Earth’s interior in an indirect and non-destructive way by using measurements of various signals which propagate through the Earth — for instance seismograms recording the Earth’s vibrations after an earthquake. In my research, I develop processing tools which fully exploit these recordings and build images of the Earth, from its shallow near surface to its deep interior. These models contain quantitative information on the Earth properties which help us understand ongoing geological processes, and manage natural resources such as hydrocarbons or groundwater.
Project title: Seismic imaging with massive datasets using sparsifying transformation methods
Technical description
My research concerns the quantitative imaging of the Earth’s subsurface, using in particular seismic and electromagnetic waveforms inversions, with applications at various scales: from the shallow subsurface (hydrogeophysics) to basin and lithospheric imaging (seismology).
Within iCRAG, my project focuses on multiscale seismic waveform inversions involving sparse parameterisations, which consist in expressing the seismic models in wavelet basis rather than with usual pixels. This approach reduces the computational costs of waveform inversion, while also enabling a multiscale resolution analysis of the solutions.
These developments are applied at two main scales to study the western Ireland’s offshore basins. At the North Atlantic scale, I estimate the distribution of shear-wave velocity and of its radial and azimuthal anisotropy in the crust and in the upper mantle, which can be interpreted in terms of lithosphere thickness, temperature, and deformation. At the basin scale, I produce high-resolution images of seismic parameters which can be in turn linked to properties of great interest for the characterisation of the reservoirs, such as rock porosity and fluid content. These images are expected to provide new insights into the nature of debated structures, including the Porcupine Median Ridge, and therefore to contribute to the understanding of the tectonic history of the basins.
Role
- Postdoctoral Researcher
Institution
- DIAS
Research Area
- Enabling Methodologies
Expertise
- Geophysics, Inverse Problems, Seismic Imaging, Seismology, Waveform Inversion
