Quaternary Paleomagnetic Studies in Japan

抄録

Various geomagnetic phenomena have been revealed by paleomagnetic and archeomagnetic studies on the Japanese Quaternary. Archeo-secular variations of the geomagnetic field in Japan are clarified for the past 2, 000 years. Fairly big local gradients in the geomagnetic direction are found within Japan.
Studies on tephra layers and marine and lake sediments, revealed that several geomagnetic events or excursions occurred during the Brunhes normal polarity epoch. These events and excursions will provide very good time markers to correlate with the middle and late Quaternary strata.
Age of paleo-earthquakes can be determined by using remanent direction of sediments squeezed out by ancient earthquakes, because their magnetization recorded the geomagnetic field at the time when the earthquakes occurred.