View article

In 1987 the Swedish Nuclear Fuel and Waste Management Co. (SKB) funded the shooting of a 1.7-km long, high‐resolution seismic profile over the Finnsjön study site using a 60‐channel acquisition system with a shotpoint and geophone spacing of 10 m. The site is located about 140 km north of Stockholm and the host rocks are mainly granodioritic. The main objective of the profile was to image a known fracture zone with high hydraulic conductivity dipping gently to the west at depths of 100 to 400 m. The initial processing of the data failed to image this fracture zone. However, a steeply dipping reflector was imaged indicating the field data were of adequate quality and that the problem lay in the processing. These data have now been reprocessed and a clear image of the gently dipping zone has been obtained. In addition, several other reflectors were imaged in the reprocessed section, both gently and steeply …