Delphine Fitzenz

Research Scientist

Centro de Geofisica de Evora
University of Evora
Rua Romao Ramalho, 59
7002-554 Evora, Portugal

Tel.: +351 266 740 800 (extension 54 70)
Fax: +351 266 745 394
Email: delphine(at)uevora.pt

Curriculum Vitae
Please scroll down to find a list of downloadable publications, or click here to jump to the research projects!

My collaborators: see map

NOTE: MORE UP-TO-DATE INFORMATION, AND COMMENTED LIST OF PUBLICATIONS PER RESEARCH AREA
CAN BE FOUND AT my page on the team WIKi

The Students' corner

Research topics :

- Fault zone rheology and strength, role of fluids in faulting;
- Quantitative analysis of experimental rock deformation data
- Quantification and propagation of uncertainties (model, i.e., epistemic; or data, i.e., aleatory)
- Data integration into forward numerical models of seismogenic faults
- Seismic hazard assessment

My research is dedicated to the characterization and the modeling of the temporal evolution of active faults, with the aim of moving towards more process-based seismic hazard assessment methodologies.
I strongly believe that models of the physics of faulting are a unique integrative tool (see poster). They can help relate the data acquired in the field, in the lab, or by satellite to each other, and can therefore help us better understand the behavior of faults and their associated hazard to society.
The integration of data into numerical models requires developing inverse methods allowing the quantification of the uncertainties related to the acquisition of the data and to the choice of given models among a host of competing models. It also required building generative (probabilistic forward) models allowing the propagation of these uncertainties. The results of such numerical simulations can then be shown as probability density function (for example, pdf of time to failure).

The three main tasks I have been working on in recent years are:

1) the development of a framework for the forward modeling of faults, first deterministic, then Bayesian (though still mostly physics-based);
2) the analysis and integration of experimental rock deformation data, namely to better constrain the interseismic fluid pressurization of fault zones;
3) the development of novel methods to invert high-resolution optical images taken before and after a tectonic event for a dense surface deformation field. The idea is to better constrain coseismic source models and their uncertainties, but also rheological models for the case of creeping faults for example.

The methods I have been using:

1) the development of modular deterministic numerical models using analytical solutions when possible, diffusion by finite differencces, numerical integration of systems of coupled differential equations (Runge-Kutta), etc.
2) generative models (forward Bayesian models) whose algorithms are developed based on graphical models, and that are solved analytically when possible or by Monte Carlo sampling methods.
3) Bayesian inference, guided by graphical models. Reparametrizations and Laplace approximations when possible, numerical optimization methods (conjugate gradient, etc.). Next step: model selection

The programming is carried out in fortran 90/95 avec OpenMP, C, C++, octave, gnuplot, matlab, under unix or MacOSX.

About the research projects I lead or am involved in:

- Click here! and have a look at our team wiki

Recent peer-reviewed papers :

Maury V., Piau J.-M., and D.D. Fitzenz, accepted 2011, Mechanical effects of the presence of gas on the behaviour of faults modeled as a sandwiched Camclay material, Proceedings of the International Rock Mechanics Conference, to be held in Pekin in 2011.

B. Le Goff, D.D. Fitzenz, and C. Beauval, 2010 Towards a Bayesian seismotectonic zoning for use in Probabilistic Seismic Hazard Assessment (PSHA) , MaxEnt, AIP.

D.D. Fitzenz, M.A. Ferry and A. Jalobeanu, 2010 Long-term slip history discriminates among occurrence models for seismic hazard assessment , Geophys. Res. Lett. pdf

Y. Bernabe, B. Evans, and D. D. Fitzenz, 2009, Stress Transfer during pressure solution compression of rigidly coupled axisymmetric asperities pressed against a flat semi-infinite solid , Pageoph, vol. 166, N. 5/7 special issue "Rock Physics and Natural Hazards" (eds., Sergio Vinciguerra and Yves Bernabe).

A. Jalobeanu, D.D. Fitzenz, 2008 Inferring deformation fields from multidate satellite images - IEEE International Geoscience & Remote Sensing Symposium (IGARSS'08 ), Boston MA, USA, Jun 2008

A. Jalobeanu, D.D. Fitzenz, 2007, Robust disparity maps with uncertainties for 3D surface reconstruction or ground motion inference, Photogrammetric Image Analysis (PIA'07), Munich, Germany, Sept 2007.

Fitzenz, D. D., A. Jalobeanu, S. H. Hickman, 2007, Integrating Laboratory Creep Compaction Data with Numerical Fault Models: a Bayesian Framework, J. Geophys. Res., 112, B08410, doi:10.1029/2006JB004792.

Fitzenz, D. D., A. Jalobeanu, S. H. Hickman, and N. Sleep, 2005, Integrating laboratory compaction data with numerical fault models: a bayesian framework, Bayesian inference and maximum entropy methods in science and engineering : 25th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering, San Jose, California, August 2005, Melville, N.Y. : American Institute of Physics.

Fitzenz, D.D. and S.A. Miller, 2004, New insights on stress rotations from a forward regional model of the San Andreas fault system near its Big Bend in southern California, J. Geophys. Res., Vol. 109, B08404, doi: 10.1029/2003JB002890.

Fitzenz, D.D. and S.A. Miller, 2003, Fault compaction and overpressured faults: Results from a 3D model of a ductile fault zone, Geophys. J. Int., Vol. 155, pp. 111-125.

Fitzenz, D.D., 2002, Generalization of a 3-dimensional fault interaction model including tectonics, fluids, and stress transfer, PhD thesis, ETH Zurich.

Fitzenz, D.D. and S.A. Miller, 2001, A Forward Model for Earthquake Generation on Interacting Faults Including Tectonics, Fluids, and Stress Transfer, J. Geophys. Res., Vol.106, B11, p.26,689.

A few links of interest:

- Our SSA 2011 Special Session on Probabilistic Methods in Tectonophysics and Seismic Hazard Assessment See list of all session here ,
- 5th International Workshop on Statistical Seismology: Physical and Stochastic Modelling of Earthquake Occurrence and Forecasting,
- PIA07 Photogrammetric Image Analysis 19-21 September 2007
- Incitation à l'utilisation scientifique des images SPOT : ISIS
- Borehole geophysics at the U.S. Geological Survey
- Earth-prints repository: links towards recent contributions at international workshops or conferences (e.g., Fitzenz)

And just to relax:

Visitez le Haut-Jura !