Adelinet M. auteur aut IRD Dorbath Catherine auteur aut IRD Le Ravalec M. auteur aut IRD Fortin J. auteur aut IRD Gueguen Y. auteur aut IRD text journalArticle eng text/pdf born digital access The inversion of seismic data to infer rock microstructural properties and fluid flow patterns in the crust is a challenging issue. In this paper, we develop an effective medium model for estimating velocities in porous media including both pores and cracks and use it to derive the distribution of crack density beneath the Reykjanes Peninsula from accurate tomography data. Outside the active hydrothermal areas, crack density is shown to decrease with depth. There are two main reasons for this: the closure of cracks because of the increasing overburden and the secondary filling of cracks because of hydrothermal flows. However, crack density may locally increase with depth beneath the southwestern part of the Kleifarvatn lake. This is consistent with the presence of a deep reservoir with supercritical fluids under pressure, which may activate hydrofracturing processes. We recognize that capturing the link between seismic data and the physical properties of crust is very difficult. This study shows that a combination of mechanical concepts and effective medium theory contributes to improve our understanding of the phenomena occurring within the Icelandic crust. Citation: Adelinet, M., C. Dorbath, M. Le Ravalec, J. Fortin, and Y. Gueguen (2011), Deriving microstructure and fluid state within the Icelandic crust from the inversion of tomography data, Geophys. Res. Lett., 38, L03305, doi:10.1029/2010GL046304. specialized ISLANDE 066 38 L03305 2011 0094-8276 https://www.documentation.ird.fr/hor/fdi:010053140 10.1029/2010gl046304 0094-8276 [F B010053140] https://www.documentation.ird.fr/hor/fdi:010053140 https://www.documentation.ird.fr/intranet/publi/2011/03/010053140.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2011-04-07 2017-08-23 fdi:010053140 fre