Corentin Gouache

 gouache

 

Stochastic generator of earthquakes in low-to-moderate seismic activity context: from data to hazard. Study case in French territories.

Supervisor: Jean-Marc Montel (CRGP)

Co-supervisors: François Bonneau (RING) - Pierre Tinad (CCR)

Objectives:

French mainland seismicity is considered as low-to-moderate. Indeed, only a few damaging earthquakes occured in this territory over the last century. This lack of data (earthquakes recorded but also strain rates, active faults known...) is the main issue for who deals with seismic hazard assessment. This observation leads us to query the applicability of the classical seismic hazard assessment scheme, mainly developped in high seismicity regions (Californie, Japan...), to low-to-moderate seismicity areas. This classical seismic hazard assessment scheme is fond of parameters hardly determinated from sparse data otherwise arbitrarily.

Our approach is to use the nonparametric inter event time method in order to compute objective reccurrence rates of earthquakes in function of their magnitude. We developped an implementation to stabilize the results when data are really spare: for large magnitudes. This method allows us to calculate reccurrence rates without increasing the uncertainties and using arbitrary parameters. A Monte Carlo Markov Chain is applied on initial data to propagate the magnitude uncertainties. This stochastic process leads to a probability density function of reccurrence rate for each magnitude step instead of only one deterministic result.

For these pdf of reccurrence rate we generate synthetic earthquakes on the French mainland territory in order to overcome the lack of data. Then for each earthquake the hazard (Peak Ground Acceleration, PGA) is calculted thanks to the Ground Motion Prediction Equations (GMPE). The large amount of GMPE and the simplicity of these equations regarding the complex physical processes involved in the seismic waves propagation force the seismic hazard community to use several weighted GMPE. These weights are set arbitrarily from a group of experts. We want to overcome this subjectivity by weight a set of pre-selected GMPE thanks to numerical simulatations of seismic waves propagation through the RegSEM code (Spectral Element Method) (Paul Cupillard).

Contact Information

E-Mail :This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone number:+33 (0)3 72 74 45 26
ENSG office number:G209
Personal Web Site:https://www.researchgate.net/profile/Corentin_Gouache

Publications

2019

C{\'e}lia Louarn and Fran\c cois Bonneau and Corentin Gouache.
in: 2019 Ring Meeting, ASGA
Corentin Gouache and Paul Cupillard and Pierre Tinard.
in: Colloque national AFPS 2019, Association Française du génie ParaSismique
Corentin Gouache and Pierre Tinard and Jean-Marc Montel.
in: Colloque national AFPS 2019, Association Française du génie ParaSismique
Corentin Gouache and Francois Bonneau and Pierre Tinard.
in: {{IAMG}} 2019, {International Association of Mathematical Geosciences}
Corentin Gouache and Fran\c cois Bonneau and Pierre Tinard.
in: 2019 Ring Meeting, ASGA

2018

2017

Michel Saint Blanquat and Flora Bajolet and Philippe Boulvais and Alexandre Boutin and Camille Clerc and Adélie Delacour and Deschamp Fabien and Mary Ford and Serge Fourcade and Corentin Gouache and Arjan Grool and Pierre Labaume and Lagabrielle Yves and Abdeltif Lahfid and Baptiste Lemirre and Patrick Monié and Philippe Parseval and Marc Poujol.
in: EGU 2017