Emeritus Professor since 2017

contact: jean.virieux[at]univ-grenoble-alpes[dot]fr

contact: jeanvirieux[at]gmail[dot]com

Seismic imaging using seismic waves

Imaging Earth structures from the complex near-surface to lithospheric structures through crustal structures.

Imaging the complex ruptures of earthquakes: challenging imaging with very local rupture processes and long-distance interaction.

My research activity concerns the interpretation of seismic signals in two directions. Dynamic rupture, highly non-linear problem for understanding earthquakes, can be better analyzed as we have dramatically increased the number of seismic records nearby the source without saturation and as we have improved the quality of the modelling of this difficult problem : the rupture depends on the local precision of the stress field nearby the fault while waves should propagate over long distances for building up this stress field. Reconstruction of slip distribution over complex fault geometries is now possible.
These tools for seismic wave propagation in heterogeneous media allow us to reconstruct accurately local, crustal and global structures using same physical backgrounds : a key tool for oil exploration. Both reconstructions allows a better interpretation of what is occurring during an earthquake and a high resolution image of complex structures (Volcanic zones –Naples area – or extensive zones – Corinth Gulf -). The seismic imaging has now reached a mature level with half-the-wavelengh resolution as we are able to exploit the whole seismic signal, making us ready for tracking small changes and fluid migrations, thanks to the increase of seismic data.

A cross-section of travel-time tomography over Western Alps

Initial model from the work of Ahmed Nouibat preprint (pdf)