(a) Area covered by the regional local earthquake tomography model of the western Pyrénées. The black line indicates the location of the vertical cross section shown in the lower panel, the red open circles the epicenters of the earthquakes, and the blue open triangles the stations used to obtain the model. (b) NNE–SSW vertical cross section through the regional P-wave velocity model. The black circles show the projection of earthquakes in a 10 km corridor along the profile.