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Bruguera seismic station (CBRU)

Code: CA.CBRU Name: Bruguera 

Latitude: 42.2844 N Longitude: 2.1790 E Height: 1327 m

Local depth: - m

Owner: Institut Cartogràfic i Geològic de Catalunya

Subsoil features

Lithology

Period

Vs30 (m/s)

Classe EC8

F0 (Hz)

Limestones and lutites

Cambroordovician

1057

A

-

Instrumentation by channels and periods

Channels

Start date

Sensor type

Digitizer type

Instrumental response

HHZ, HHN, HHE

01/12/2000

Broadband velocimeter

24 bits

[StationXML]

Geophysical characterisation

H/V Spectral ratio from seismic noise

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

P-waves velocity  model

In the P-waves velocity model, obtained by seismic refraction tomography, a surface layer of low velocity materials, less than 1000 - 1500 m/s, is observed. Usually these values ​​are associated with unconsolidated materials. Its thickness is about 5 meters, although in the vicinity of the seismic station this level is interrupted and surface values ​​of more than 1500 m/s emerge. At depths of about 10-15 meters, velocities above 2500 m/s are reached, usually associated with unweathered non-ripable rock. However, velocities above 2000 m/s are observed, between 5 and 10 meters deep, close to the seismic station. This level is interpreted as the fractured and/or altered bedrock.

P-waves velocity model of Bruguera seismic station.

S-waves velocity model

In the shear wave propagation velocity model (VS) obtained by seismic refraction tomography, a surface layer of unconsolidated materials (VS < 500 m/s) is detected and it is interrupted in the vicinity of the seismic station. The rock basement (VS > 1000 m/s) is located about 5 meters deep in the sector of the profile closest to the seismic well. The isoline that delimits the bedrock layer (VS > 1500 m/s) is located at a depth of about 20 meters.

S-waves velocity model of Bruguera seismic station.

Images

5 multimedia

Geological site conditions: Rocky outcrop (Limestones and calcareous lutites, Upper Devonian).