Seismic tomography at Popocatépetl volcano, Mexico

Pia Berger (1) , Jean-Luc Got (2) , Carlos Valdes Gonzalez (3) , Vadim Monteiller (4)

1 Instituto de Geofisica [Mexico]
2 Géophysique des volcans & géothermie
3 DTP - Dynamique terrestre et planétaire
4 ISTerre - Institut des Sciences de la Terre

We performed the first 3D seismic tomography of the Popocatépetl volcano, Mexico, from the inversion of the P-wave arrival times of nearly 1500 earthquakes recorded by up to 11 seismic stations of the permanent CENAPRED-SSN network. We used the Bayesian tomographic algorithm developed by Monteiller et al. (2005) to perform this P-wave travel-time tomography and carefully choose optimal regularization hyper-parameters. Sensitivity tests show that the inversion is correctly constrained under the volcano from − 1 to 4 km depth b.s.l.. At these depths, the optimal tomographic model mainly shows low-velocity volumes surrounded by higher-velocity volumes. Lateral heterogeneity is strong: the variation of the P-wave velocity may reach up to ± 20% of the average value at a given depth. Low-velocity volumes correlate well with results from former geological and geophysical studies.

Mots clés: Popocatépetl; seismic tomography; volcano-tectonic events

Domaines: Géomorphologie

Pia Berger, Jean-Luc Got, Carlos Valdes Gonzalez, Vadim Monteiller. Seismic tomography at Popocatépetl volcano, Mexico. Journal of Volcanology and Geothermal Research, 2011, 200 (3-4), pp.234-244. ⟨10.1016/j.jvolgeores.2010.12.016⟩. ⟨insu-00679305⟩