Abstract
The shallow seismic reflection method has been used increasingly since 1980 in applications shallower than a few hundred meters for geotechnical and active fault surveys. The free-fall and accelerated types of weight drop have been used generally as a seismic source, however, it is difficult to operate such sources in urban areas because of damaging to paved roads.
The sweep type source by using a electro-magnetic vibrator has been developed by one of the authors, which is based on the principle of the Vibroseis® system. This type of seismic source, in which received signal is compressed into a wavelet by cross-correlation with transmitted signal, is characterized by higher S/N ratio, adjustable frequency range and possible operation in urban areas.
The shallow seismic reflection method by using the sweep type source was applied to geotechnical surveys and some faults are detected in urban areas in Kinki district.
