Recent Issues Affecting Forecast of Subduction Zone Great Earthquakes in Japan Through Paleoseismological Study

Abstract

Because the 2011 great Tohoku earthquake was accompanied by phenomena similar to those associated with the 869 Jogan earthquake, as reconstructed on the basis of historical and geological evidence, paleoseismology is recognized for its potential effectiveness in earthquake forecasting. In attempts to avoid such unexpected situations as the 2011 Tohoku event when taking disaster prevention measures, the Japanese government and local administrations announced a maximum class model for earthquakes and tsunamis that is not based on paleoseismological evidence. Thus, paleoseismologists must both inductively study the reconstruction of evidence from the past and deductively evaluate the maximum class earthquake and tsunami.