PhD on the origin of seismicty related to a flooded abandoned coal
mining district at Gardanne, France


Created in 1990, INERIS (National Institute of Industrial Environments and Risks, www.ineris.fr) is an industrial and commercial french public institution (EPIC) under the supervision of the Ministry of the Environment. Its mission is to conduct studies and research to prevent accidental or chronic hazards to man and environment related to industrial activities, chemical substances and underground operations.

The head quarter of INERIS, with a size of more than 40 hectares, is located in the Oise department, 40 minutes from Paris and 10 minutes from Senlis / Chantilly (A1) - 30 minutes from Paris Nord + shuttle bus.

The successful candidate will work at the INERIS quarter at Nancy (at the Ecole des Mines) for around 70% of working time and 30% at the IPGP and / or BRGM-DPSM.

Context and thesis objective:

Seismic hazard in flooded, post-mining districts and consequent damage from ground shaking is poorly understood, but can be a real concern for the close living population. Large seismic events with M > 5 are known from active mining districts. These events are often directly induced by mining activity and thus, could be in some cases anticipated from local seismic monitoring. In flooded post-mining districts, seismic events have been observed in the context of partial underground collapses, fluid induced redistribution of the environmental stresses, and the reactivation of pre-existing fault structures next to the mining district. The estimation of the associated seismic hazard is quite challenging, depending on many complexly interacting factors, such as the mine geometry and geological constitution, its long-term alteration behavior (modified by the presence of fluids), meteorological impacts and climate changes, triggering from regional or global natural earthquakes, and the presence of pre-existing fault structures and tectonic stresses.

To improve seismic hazard assessment in this context, this thesis will focus on the study of a flooded abandoned coal mine at Gardanne in the Provence region, South of France. As part of operational monitoring and seismic survey coordinated by the BRGM-DPSM, INERIS installed a permanent microseismic monitoring network in 2007 which recorded up to today several thousand of microseismic events. In response to increased seismic activity, the network has been completed by installing several temporary INERIS and BRGM-DPSM stations. Seismic activity seems to be strongly related to relatively small fluctuations in the groundwater level in the mining workings and was several times clearly felt by the local population. The aim of this thesis is to characterize the origin of the observed seismicity and to develop a hydromechanical model explaining the observed phenomena. In this context, first a comprehensive study of seismic data will be required (including determination of source locations, parameters and mechanisms) helping to characterize the nature of the observed seismic sources. Together with other field data (geology, flooding history, natural fracturing, mining geometry etc ...) these results will then be used to study in detail the link between mine flooding and seismicity using adapted numerical hydromechanical modeling approaches. Existing data may be completed by supplementary hydrological and seismic monitoring experiments.

This thesis is part of the research project "Dynamic rupture and induced seismicity " of the research axis 190 "CORDIS" of INERIS. This work of thesis will be carried out in collaboration with the Institute of Physics of the Globe of Paris, the BRGM and GEORESSOURCES. It will also be led with the support of GEODERIS.

Profile:

Applicants must hold a master's degree or equivalent in the field of Geoscience, Geoengineering and/or Physics. An advanced background in seismology, signal processing and basic programming skills are an advantage. Hydrogeological and hydromechanics modelling experience is appreciated.

For your application please send to ineris17041@earthworks-jobs.com:

  • a brief account of the applicant's research interests and motivation for applying for the position.
  • your CV.

posted: 12 April 2017     Please mention EARTHWORKS when responding to this advertisement.