First 3D characterization of the Rhône Messinian Canyon in the Tricastin area from complementary geophysical approaches
Abstract
Superficial geological layers can strongly modify the surface ground motion induced by an earthquake through the so-called “site effects”. One common approach to estimate these local effects at a specific site relies on the numerical simulation of the ground motion. This requires a characterization of the Earth’s subsurface to build a representative model of the seismic wave propagation medium. In this study, we focus on the area of the Tricastin Nuclear Site (TNS). TNS is located over an ancient Rhône canyon whose characteristics and complex geometry make it a good candidate for generating site effects. We present here the first results of 3D medium characterization based on geological investigations and on different types of seismic data, that is, the seismic ambient noise and data from an active seismic exploration survey. The results provided by the different imaging approaches considered are complementary and the first comparison presented in this article highlights the interest of comparing these different results to obtain an overall picture of the subsurface conditions of the site.
Origin : Files produced by the author(s)
licence : Copyright
licence : Copyright