1983 年 36 巻 3 号 p. 359-372
Active faults in the Kanto Plain have been studied by the geophysical prospecting method, such as the seismic and the gravity measurements. It is revealed that the active fault is accompanied with the basement fault whose displacement exceeds several hundreds meters in its deeper part. This evidence shows that the geophysical method is a usefull method to detect the hurried active fault which is covered by the alluvium. It is concluded that the following order of study, firstly detecting the basement fault by means of the geophysical prospecting method, and secondly carrying out the precise geomorphological, geological and test well surveys, is a practical method for the study of hurried active fault in the alluvial plain. Comparing the surface displacement or the displacement velocity of active fault with the displacement of its basement fault makes it possible to estimate the activity of active fault.