Ebre seismic station (EBR)
Code: EB.EBR Name: Ebre Latitude: 40.8201 N Longitude: 0.4939 E Height: 36 m Local depth: 7 m Owner: Observatori de l'Ebre |
| Subsoil features | ||||
|---|---|---|---|---|
| Lithology | Period | Vs30 (m/s) | Classe EC8 | F0 (Hz) |
| Gravels and blocks with sandy clay matrix | Quaternary | 921 | B | 0.52 |
| Instrumentation by channels and periods | |||||
|---|---|---|---|---|---|
| Channels | Start date | End date | Sensor type | Digitizer type | Instrumental response |
| HHZ, HHN, HHE | 11/12/2007 | 17/01/2023 | Broadband velocimeter | 24 bits | [StationXML] |
| HNZ, HNN, HNE | 17/01/2023 | - | Accelerometer | 24 bits | [StationXML] |
The Ebre seismic station (EBR) is owned by the Ebre Observatory (OE) and is the first seismic station in Catalonia, installed in 1904 and still active. As the technology has advanced, the instruments have been updated and today it is still in operation thanks to the collaboration between the OE and the ICGC. You can consult here the lists and details of the seismographs previously installed at this station, as well as access to their scanned seismic records.
Geophysical characterization
H/V Spectral ratio from seismic noise
A peak is observed around 0.5 Hz that can be related to the fundamental frequency of the soil and, therefore, an acoustic impedance contrast is expected in the subsoil.
H/V Spectral ratio of seismic noise records from Ebre seismic station.
P-waves velocity model
In the P-waves velocity model (Vp) obtained by seismic refraction tomography, it is characterized by a package of low-velocity materials (Vp < 2000 m/s) that extends to 20 meters of depth (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 sound, non-rippable rock and that can be interpreted as the bedrock.
P-waves velocity model of Ebre seismic station.
S-waves velocity model
In the shear wave propagation velocity model (Vs) obtained using the array technique, a surface layer of 2 meters thick and 200 m/s is observed. Below this layer, the velocity increases to 750 m/s and extends to a depth of 30 meters. Then, a deep layer with a velocity of about 900 m/s is observed that extends to more than 400 meters deep. The bedrock is detected at approximately 415 meters deep and has a velocity of about 2000 m/s.
S-waves velocity model of Ebre seismic station.