Rettew Inc and Seismotech S.A. collaborated to carry out a pilot Passive Seismic Survey in the NASA White Sands Test Facility, in southern New Mexico.
A full range of passive seismic methods were applied, exploiting a pilot 10-seismograph network that was installed in the WSTF site, covering an area of approx. 3.4 x 1.5 km and operating during a 3-week monitoring period. The actual dimensions of the installed passive seismic network were extended to an area of approx. 5.6 x 5 km, in order to better control the hypocentral parameters of possible seismic events.
The scope of this study was the acquisition and processing of a sample dataset, in order to provide information regarding the applicability of passive seismic techniques, as well as recommendations regarding the optimum design of a future “full-scale” Passive Seismic project in the area.
The passive seismic techniques that were evaluated for their applicability were Local Earthquake Tomography, Reflected-Wave Passive Seismic Interferometry, Ambient Noise Tomography and Surface-Wave Tomography. Additionally, the suitability of the instrumentation used was assessed, while a significant part of the scope of work consisted of the estimation of a coarse 3D velocity model of the subsurface below the study area, in order to demonstrate the capabilities of passive seismic techniques, even though the acquisition time, the dimensions of the pilot survey area, as well as the number of seismic stations used, were very limited.