ESR3.1: Johannes AicheleElastography and seismology

Johannes Aichele is a graduated geophysicist that started his studies in georesource management and geosciences and perpetually specialized in geophysics. He finished his Bachelor at the RWTH Aachen which included a study visit in Toulouse, France with a thesis on a palaeo tsunami: “Sedimentological analysis of tsunami deposits in the northwestern section of Barbate beach (Gulf of Cádiz, Spain)”. Subsequently he completed the IDEA League Joint Master in Applied Geophysics. Attending TU Delft , ETH Zurich, and RWTH Aachen he concluded his studies with a Master thesis on geothermal reservoir simulation (“Influence of Structural Uncertainties in Deep Faults on Fluid and Heat Flow in Sedimentary Basins”) in cooperation with GFZ Potsdam.

Main host institution:

Laboratory of Therapeutic Applications of Ultrasound, Inserm (Lyon, France)

Supervisor:

Stefan Catheline (stefan.catheline @ inserm.fr)

Secondment institutions:

• Laboratoire de Mécanique et d’Acoustique (LMA), CNRS (Marseille, France)
• Institut des Sciences de la Terre (ISTerre), CNRS (Grenoble, France)

Objectives:

In some soft solids, including organic tissue (flesh), compressional waves are much faster than shear waves, so that the former can be used to monitor the propagation of the latter via "ultrafast" imaging. This finding of medical acoustics has been successfully employed by seismologists to reproduce slow earthquakes and supershear rupture in the laboratory. So far, laboratory work has been limited to relatively unrealistic, soft solids (poly-vinyl alcohol media), and this project’s objective is to overcome this limitation.

Expected results:

The student, based at INSERM but working in close collaboration with the Grenoble (Isterre) and Marseille groups (LMA), will conduct similar experiments on soft brittle materials, more closely reproducing real seismic rupture; laboratory work will be accompanied by spectral element (SPECFEM) simulations, supervised by the Marseille group.

international conference:

ASA - 5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan, Honolulu Hawaii, 28/11-2/12/2016: poster on Shear wave elastrography reveals dispersion regimes in porous materials

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