Prior and real-time estimations of geohazards related to earthquakes and volcanic eruptions are essential to mitigate disasters. This review discusses the results of the past five years through “the Second Earthquake and Volcano Hazards Observation and Research Program (Earthquake and Volcano Hazard Reduction Research)” on the real-time and prior estimation of geohazard related to earthquakes and volcanic eruptions. Investigations have been conducted through cooperation among the research fields of seismology, volcanology, disaster prevention engineering, and social science, in conjunction with the practical services of on-site works to effectively provide advanced and real-time geohazard estimations to people. While remarkable results have been achieved and progress has been made in each research field, the issue remains of how to disseminate the results to society, mainly how to translate the information into disaster information and make it easier for the public to understand.

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