Beuda seismic station (CBEU)

Geophysical characterisation

H/V Spectral ratio from seismic noise

H/V Spectral ratio from seismic noise records of Beuda seismic station. It is observed an almost flat curve, without any significant peak which might be associated to  the fundamental frequency of the soil. This behaviour is typical of rock sites.

H/V Spectral ratio of seismic noise records from Beuda seismic station.

P-waves velocity  model

In the P-wave velocity model, obtained by seismic refraction  tomography, a velocity gradient is observed from the surface (V_P ≈ 1000 m/s) to about 15 meters depth (V_P ≈ 3000 m/s). At depths of about 10-12 meters, velocities above 2500 m/s are reached, associated with non-ripable rock (bedrock). In the sector of the profile closest to the seismic well, the investigation depth is not enough to detect the 2500 m/s line, but velocities higher than 2000 m/s are observed at only 3 meters depth.

P-waves velocity model of Beuda seismic station, obtained by refractive seismic tomography technique.

S-waves velocity model

In the shear wave propagation velocity model (V_S) obtained by seismic refraction tomography, the rock basement (V_S > 1000 m/s) is detected at only 3 meters depth along the entire profile. The isoline that delimits the very hard rock layer (V_S > 1500 m/s) is located at a depth of about 15 meters, but in the sector of the profile closest to the seismic well this value is shallower, only 5 meters deep.

S-waves velocity model of Beuda seismic station, obtained by refractive seismic tomography technique.