Geophysics - A Proven Tool In Underground Laboratories

Geophysics provides the link between the geosciences, geoengineering, and the needs of the particle physics experimenters. Measurements of the physical properties of the rock mass both near drifts in the underground and at distances away from the free surfaces is important during the construction phase and during the maintenance phase of the facility. It is most appropriate that this subdiscipline of physics will be in a position to assist the experiments of the particle physics community. Geophysical techniques as site characterization tools can be tailored to investigate the regions close to the "surface", in this case the faces of the drifts, or more deeply. Typical rock parameters of interest include the electrical properties of the rock, the acoustical properties, the distribution of densities, and the distribution of magnetic properties within the rock mass. Creation of the NUSL will be an excellent opportunity to apply the tremendous advances in underground geophysics, which evolved during the last 20 years. These advances represent a wealth of innovative techniques often developed in concert with the design and construction of underground structures. Many of the subsurface sites are a result of construction for waste management purposes, but they also include specialized regional observatories developed in scientific underground laboratories. The great depths required by the NUSL and the lateral extent of the required excavations will allow geophysics to provide a suite of tools to assist in the development of methods to increase excavation efficiency, to increase safety, to characterize the rock mass at depth in terms of stress and rock mechanics properties. Because the NUSL will require a large mass of rock overlying the experiment, it will be possible to conduct geophysical experiments that will take advantage of the access to the underground and which will contribute to the understanding of Earth structure on a more regional or global basis.

Geophysics at the National Underground Science Laboratory (NUSL)