Workshop for Identifying Issues Due to the Dissemination of the Nankai Trough Earthquake Information by News Media

We conducted a workshop to identify potential issues that could be caused by news media’s dissemination of the Nankai trough earthquake information (extra). The Nankai trough earthquake information (extra) was introduced in 2017 by the Japanese government, which will be issued when anomalous phenomena that suggest the occurrence of devastating earthquake along the Nankai trough are observed. However, the information could not state the specific date, location, and magnitude of the impending earthquake because of the limitation of earthquake science. We held a multi-stakeholder workshop to discuss how this ambiguous scientific information could be delivered and disseminated by news media to promote risk reduction as well as to avoid social disruption. Local news media including television, radio, and newspaper from four separate regions in Japan participated in the workshop along with researchers on seismology and disaster information studies. A “partial-area-rupture case” where a large-scale (magnitude 8 class) earthquake occurs on the western side of the Nankai trough was discussed. A scenario that describes the issuance of various warning and disaster information including the Nankai trough earthquake information was presented along the timeline, which then the participants discussed how the news media would respond to the sequence. Although it was a short workshop and the scenario was quite crude, several unrecognized issues were successfully found.