Welcome to the Réseau Numérique en Terre Solide (NuTS), a CNRS thematic network (RT) that aims to foster the community of developers and users of numerical tools for solid earth science. Our goal is to make this community more visible, efficient, and informed through a series of conferences and training courses on digital science, from data manipulation to high-performance scientific computing.

We are excited to announce the second workshop of the RT NuTS, which will take place from May 28^th to  May 31^st in Strasbourg. This workshop is dedicated to "inverse problems" in solid earth science with a focus on numerical and computational aspects. It is divided into two parts: the first two days will feature scientific talks, and the last two days will offer hands-on practicals on two topics (see the program below).

During the practicals, attendees will have the opportunity to work with Jupyter Notebooks and the Python language, using the cutting-edge computing resources provided by the GLiCID mesocentre, including a series of A100 GPU. The practicals will cover various topics, from Bayesian inference and uncertainty quantification hands-on to automatic differentiation in the Julia language.

We are planning a poster session dedicated to inverse problem-related studies, especially those that are in progress and require further discussion. We welcome contributions from students and researchers interested in sharing their plans and unfinished work with the community.

We invite you to join us for this exciting workshop, where you will learn from experts in the field, gain hands-on experience with inverse problem-related practical programming, and network with other researchers in solid earth science. Do not miss this opportunity to advance your skills and knowledge in numerical and computational science.

To register for the workshop, please click on the "Register Now" button. If you have any questions or need assistance with registration, please don't hesitate to contact us. We look forward to seeing you in Strasbourg!

Event location:

The workshop will take place at the "EOST auspices - Manufacture des Tabacs", 7 Rue de la Krutenau, 67000 Strasbourg

Preliminary Program

The program is still under construction

Tuesday, May 28th (Afternoon)

Introduction: Yann Capdeville

Poster pitches: concise oral presentation of the posters

Special: Emmanuel Chaljub (ISTerre). Title: ¨FormaTerre in Data Terra: contribution of the Solid Earth community to the E-infrastructure of the Earth & Environment System.

Plenary Lectures:

• Jean Virieux (ISterre, SEISCOPE). Title: "What scale-dependent models from wave-matter interaction in seismology?"
• Philippe Ackerer (EOST/ITES). Title: "Estimation of several hundreds of hydrogeological parameters by model inversion in a reasonable computer time"

Wednesday, May 29th (all day)

Confirmed speakers:

• Stéphanie Durand  (LGLTPE). Title: "Tomography: the art of compromise"
• Jean-Paul Ampuero (IRD, Geoazur, Sophia-Antipolis). Title: "Kinematic and dynamic earthquake source inversion"
• Guillaume Caumon (GeoRessources, Nancy). Title: "Can we invert for geological parameters (and what does it mean)?"
• Agnès Rivière (Ecole des Mines), Ludovic Bodet (Sorbonne Université) and Alexandrine Gesret (Ecole des Mines). Title: "GW fluxes across Subsurface BOUNDaries forecasting by combined hydrogeophysics data and model"
• Alexandrine Gesret (École des Mines). Title: "Probabilistic tomography : Estimation and propagation of uncertainties"
• Manon Dalaison (IPGP). Title: TBD
• Marie-Pierre Doin (ISTerre). Title: "Constructing time series of surface deformation using satellite imagery: noise mitigation and results"
• Alexandre Fournier (IPGP). Title: " Inverse problems in terrestrial magnetism"
• Romain Brossier (ISTerre SEISCOPE). Title: "Mitigating non-linearities in seismic tomography by full waveform inversion"
• Jérémie Giraud (GeoRessources, Nancy). Title: "Trans-dimensional geometrical inversion: application to undercover imaging using gravity data"
• Laetitia Le Pourhiet (ISTeParis, Sorbonne Université). Title: TBD

Thursday, May 30th (all day)

Morning:

Practicals: Bayesian inference with Markov chain Monte Carlo sampling

Thomas Bodin  (LGLTPE)

Description: This short course will introduce Bayesian inference and uncertainty quantification. We will see how a probabilistic framework can be used to tackle highly non-linear and ill-posed inverse problems, and how data errors can be propagated towards model uncertainties. Moving beyond theory, the lab component of the course will introduce participants to Markov Chain Monte Carlo methods, a computational tool for approximating probabilistic solutions in geophysical inverse problems. Participants will gain practical experience by coding this algorithm from scratch in a simple toy problem.

Afternoon:

We will not use any "black-box" tooling but rather develop concise and performant codes (300 lines of code, max) that execute on GPUs. We will also use automatic differentiation (AD) capabilities and the differentiable Julia stack to automatise the calculation of the adjoint solutions in the gradient-based inversion procedure.

Friday, May 31th (all day)

All Day

Practicals: High-performance computing in geosciences and adjoint-based optimisation with Julia on GPUs (part 2)
Ludovic Räss (ETH Zurich) and Ivan Utkin (ETH Zurich)