Rock alteration and damage on active faults - RADIAL (2024)

Project description

The Épagny-Annecy region (Haute-Savoie) was the site of a Mw 5.3 earthquake in 1996. Since this major earthquake, micro-seismicity has been observed continuously: this could be explained by fluid/rock interactions. ISTerre has been involved in large-scale geophysical measurements at this site, which is particularly interesting for its geothermal potential. A number of studies have explored the concept of damage, notably through laboratory experiments. At this very small scale, it is possible to pre-damage samples before deforming them using mechanical presses, simulating pressure conditions analogous to those experienced at crustal depths. Several damage methods are available, enabling the creation of a variety of fracture networks conducive to fluid circulation. For different contexts, ranging from natural to induced earthquakes, we need to determine how the initial damage to a rock leads to interactions with fluids, influencing its resistance to stress and potential fracture. The project is part of an innovative approach to experimental production at ISTerre Chambéry, with strong local and societal roots for our laboratory.