在沿岸的海底堆积物中累积有过去断层活动的痕迹。通过声波探测和活塞武岩芯取样已能精密地再现这些断层的位移量和年代,并确认了笔者等提出的地震发生时间预测模型的准确性。我们认为,通过这样的海底活断层调查,能够对地震的长期危险性作出评价。 Traces of past fault activity have accumulated in the seabed sediments. The displacement and age of these faults can be accurately reproduced by sonic detection and piston core sampling, and the accuracy of the earthquake prediction model predicted by the author is confirmed. In our opinion, such a submarine active fault survey can evaluate the long-term danger of earthquakes.