Hydrogeological prospecting using P- and S-wave landstreamer seismic reflection methods

We present two case histories from different areas and geological settings in Canada where we have used a vibrating seismic source coupled to a landstreamer receiver array in hydrogeological investigations related to aquifers in glacial sediments. In Manitoba, our P-wave seismic reflection profiles are used to provide an assessment of the subsurface architecture of buried valleys, estimate the thickness and properties of both the channel fill and the overlying sediments to depths of similar to 100 m and locate optimum sites for groundwater well placements. In eastern Ontario, we collected P- and S-wave seismic reflection as well as electrical resistivity data to investigate buried esker aquifers. The geophysical data provide detailed high-resolution information (to similar to 30 m depth) on the structure of the esker core and its overlying sand cover and on the thickness and variability of the overlying fine-grained aquitard. The data presented in this paper demonstrate that shallow seismic reflection methods are very effective tools to explore, assess and evaluate groundwater reservoirs and resources. The recent advent of landstreamer receiver arrays, especially when coupled to a vibratory seismic source, makes these methods significantly more cost-effective and efficient. We now routinely collect similar to 1000 records/day, or 1.5-6 line-km/day, using our Minivib/landstreamer data acquisition system. With this type of efficient data collection, it is anticipated that the use of shallow seismic reflection methods in hydrogeological prospecting will increase as groundwater and its protection become more valued by society.