Seismic Interferometry for Mineral Exploration: Results from a Test Survey at the Lalor Mine, MB, Canada
Seismic Interferometry for Mineral Exploration: Results from a Test Survey at the Lalor Mine, MB, Canada
Previously Published Material: Preliminary results have been shown at SEG meeting recently in Denver and have been accepted for publication by Geophysical prospecting. We will be showing new beamforming analyses and f-K filerting designed to reduce artefacts in te haimge that have neverbefore been seen.
Abstract ID#: 36464
English Abstract:
Approximately 300 hours of ambient noise data were recorded on a grid of receivers covering an area of 4 km² over the Lalor mine, Canada, to test the capability of seismic interferometry to detect ore deposits in the crystalline rock environment. Underground mining activities create sources of ambient noise in the area which can be used to create virtual sources at the surface. Alongside the ambient noise survey, a larger 3D active-source seismic survey was also acquired and used to evaluate the interferometry results. The calculated virtual shot gathers retrieved by cross-correlating ambient noise at all receivers were processed following both 2D and 3D approaches using a sequence similar to the one applied to the active-source 3D data. The DMO stacked section reveals a number of events similar to those observed on the processed active seismic sections. The passive seismic interferometry results over the Lalor mining area are encouraging but image quality of passive survey is lower than the acquired active 3D survey at the area. A number of techniques such as beamforming and f-k filtering of the virtual data are being explored address this issue. Future ambient noise surveys with longer offset, shorter receiver spacing, and wider azimuth distribution could be acquired in crystalline rock environment to address the pros and cons of the method.