Shear-waves velocity structure of the Domo de San Pedro, Mexico from Ambient Noise Tomography
Francisco Muñoz-Burbano 1, Marco Calò2, Violeta Reyes-Orozco3, Matteo Lupi1
Affiliations: 1Department of Earth Sciences, University of Geneva, Geneva, Switzerland; 2Instituto de Geofísica, UNAM, Mexico City, Mexico; 3Grupo Dragon, Nayarit, Mexico.
Presentation type: Poster
Presentation time: Tuesday 16:30 - 18:30, Room Poster Hall
Poster Board Number: 8
Programme No: 5.1.14
Abstract
We present a novel 3-D shear-wave velocity model for the Domo de San Pedro (DSP) complex in western Mexico retrieved from ambient noise analysis. The volcanic system, which hosts a high-enthalpy geothermal reservoir, is investigated by inverting group velocity maps derived from empirical Green's functions, obtained by cross-correlating continuous seismic signals recorded over ten months by 20 temporary broadband stations. The resulting velocity model reveals features down to 3.5 km depth and show the regional relationship between the DSP and nearby volcanic systems within the Jalisco Block and neighbouring domains. The velocity model shows the structural controls exerted by the tectonic boundaries between these volcanic complexes. The most important finding of this study is the identification of a low-velocity volume associated with the geothermal reservoir and a fluid-rich, fractured region underlying the DSP, which extends southwestwards for several kilometers. This low-velocity anomaly is separated from the shallow DSP structures by a thin clay cap, consistent with previous studies. Our results demonstrate that ambient noise imaging is an effective technique for characterizing geothermal areas and identifying generalized structural features that can help to identify promising targets.