Mas de Barberans seismic station (CMAS)
Code: CA.CMAS Name: Mas de Barberans Latitude: 40.7256 N Longitude: 0.3138 E Height: 530 m Local depth: - m Owner: Institut Cartogràfic i Geològic de Catalunya |
| Soil features | ||||
|---|---|---|---|---|
| Lithology | Period | Vs30 (m/s) | Classe EC8 | F0 (Hz) |
| Black dolostone | Jurassic | 890 | A | - |
| Instrumentation by channels and periods | ||||
|---|---|---|---|---|
| Channels | Start date | Sensor type | Digitizer type | Instrumental response |
| HHZ, HHN, HHE | 01/04/2006 | Broadband velocimeter | 24 bits | [StationXML] |
Geophysical characterisation
H/V Spectral ratio from seismic noise
H/V Spectral ratio from seismic noise records of Mas de Barberans seismic station. A peak around 4.5 Hz is observed with H/V amplitude lower than 2. According to the criteria of SESAME project this peak cannot be interpreted as the soil fundamental frequency, since amplitude higher than 2 is required. But, the amplitude of this peak could be related to the presence of a velocity inversion or with a low impedance contrast within the near-surface layers.
H/V Spectral ratio of seismic noise records from Mas de Barberans seismic station
P-waves velocity model
The P-waves velocity model, obtained by seismic tomography provides information of the subsoil up to 10 meters depth. A first layer of variable thickness is observed, between 2 and 6 meters, with a velocity lower than 2500 m/s. These velocity values correspond to rippable materials and can be related to a fractured or weathered rock. Velocity is lower than 1500 m/s in some sectors, which is associated with low compacted material, and at some point these sectors reach 4 meters depth. Below 8-9 meters depth, the P-wave velocity exceeds 3000m/s, values that are related to non-rippable bedrock.
P-waves velocity model of Mas de Barberans seismic station
S-waves velocity model
From the surface waves analysis (MASW) a vertical shear waves velocity profile is retrieved (Vs). Four layers are identified: (1) the shallowest layer has a thickness of 2 meters and a velocity about 400 m/s. (2) Below, a high velocity layer is identified, with values higher than 1300 m/s and about 5 meters thick. (3) Underlying this second layer, a velocity inversion is identified and the Vs decreases up to 750 m/s. This layer reaches near 20 meters depth. (4) Finally the velocity increases again in the last layer up to 1200 m/s.
S-waves velocity model of Mas de Barberans seismic station obtained using the analysis of surface waves (MASW)