抄録
The extensive landslips accompanying the 1978 near Izu-Oshima earthquake were surveyed in Izu Peninsula. The earthquake fault can not be seen clearly, since the main shock lies in seabottom. But in Izu Peninsula, we can see a somewhat linear cataclysmal distribution over the distance of 17-30km from the epicenter.
Existence of earthquake fault masked with the surficial sediment is estimated from this cataclysmal line lying in the direction of N 73°W. It is inf ered that the invisible earthquake fault must have a little dislocation and/or small acceleration compared with the near focus where the acceleration may be maximum. It is interpreted that the movement of the Inatori-Omine quatenary fault is a secondary slip caused by the main fault.
The largest aftershock (M=5.8) occurred at the western end of the cataclysmal line. Disastrous feature from this aftershock is elongated from NNE to SSW and its direction is conjugate with the cataclysmal line.
