オンフォールト古地震学の展開 : 地震発生時期の解明を中心に

概要

論文の詳細を見る
The timing of past faulting events from individual faults is the most critical parameter to understand the mechanism of recurring large earthquakes and the potential of seismic hazards. High-resolution and reliable radiocarbon dating is the most fundamental method to know the time-series. Among the various physical conditions, the common lack of the Latest Pleistocene (10 to 20 ka) sediments affects the completeness of the time series most deeply in Japan. There are a number of missing events in this period and reasonable estimation of recurrence interval is usually impossible. On the other hand, recent advance of computational refinement of radiocarbon dates enables objective determination of the timing of events. The Bayesian methods are applied to dendrocorrection and recalculation of probability density distribution of a series of faulting events as well as radiocarbon dates. The recalculated chronology, given the dates are not too much affected by rework and contamination, gives high-precision objective estimates of the timing of events. The utilization of new quantitative techniques together with better survey strategy against unfavorable physical conditions will lead us to better understanding of paleoseismic activities.
2005-07-28