Galliners seismic station (CGAL)
Code: CA.CGAL Name: Galliners Latitude: 42.1480 N Longitude: 2.8752 E Height: 132 m Local depth: 0 m Owner: Institut Cartogràfic i Geològic de Catalunya |
| Soil features | ||||
|---|---|---|---|---|
| Lithology | Period | Vs30 (m/s) | Classe EC8 | F0 (Hz) |
| Conglomerates, sandstones and shales | Neogene | 446 | B | 0.7 |
| Instrumentation by channels and periods | ||||
|---|---|---|---|---|
| Channels | Start date | Sensor type | Digitizer type | Instrumental response |
| HNZ, HNN, HNE | 24/03/2022 | Accelerometer | 24 bits | [StationXML] |
Geophysical characterisation
H/V Spectral ratio from seismic noise
H/V Spectral ratio from seismic noise records of Galliners seismic station. A peak around 0.7 Hz is observed which can be related to the fundamental frequency of the soil and, therefore, a contrast of acoustic impedance is expected in the subsoil. A second peak at approximately 5.5 Hz is also observed, which would be related to a contrast of impedances between shallow soil layers.
H/V Spectral ratio of seismic noise records from Galliners seismic station
P-waves velocity model
The P-waves velocity model, obtained by seismic tomography, it is characterized by a package of low-velocity materials (VP < 2000 m/s) that extends up to 15 meters deep (rippable materials). The depth of investigation of the seismic profile is not sufficient to detect velocities higher than 2500 m/s, velocity values associated with the non-rippable rock which can be interpreted as bedrock.
P-waves velocity model of Galliners seismic station
S-waves velocity model
In the shear wave propagation speed model (Vs) obtained using the array technique is characterized by a deep layer of soft soil with a Vs of about 1000 m/s that extends to just over 300 meters deep. In the shallow part, two low-velocity layers are observed. The first is about 5 meters thick and has a Vs of 260 m/s. The second layer reaches a depth of about 20 meters and has an approximate Vs of 380 m/s. The bedrock is detected approximately 345 meters deep and has a velocity of about 2100 m/s.
S-waves velocity model of Galliners seismic station obtained using the analysis of surface waves (MASW)