Is it Possible to Conduct Seismic Wind Noise Experiments in a Wind Tunnel?

In order to assess the possibility of performing seismic experiments in a wind tunnel, a seismic study in a boundary layer wind tunnel was conducted. We were able to reduce the mechanical noise generated by the structure of the wind tunnel by modifying the test section where the geophones were planted. The comparison with seismic noise measured in field conditions corroborated the validity of our approach. Finite Element modeling of the modified test section of the wind tunnel confirmed that the signals recorded in the seismic exploration frequency band are originated by the airflow. The results of the experiments in the wind tunnel clarify two important issues about land seismic wind noise. 1) Its spectral characteristics: The wind signals extends in the whole seismic exploration frequency band; 2) The sensitivity of the components of 3C geophones to this type of noise: The horizontal components are more sensitive to this noise than the vertical one. Those are important aspects for the development of techniques and sensors to attenuate wind noise in the land seismic exploration method. The results obtained here show that wind tunnels experiments can form part of a wider investigation into the effect of wind on geophone noise.