At 9:26 pm on April 14, 2016, a magnitude 6.5 earthquake struck directly beneath Kumamoto prefecture, Japan, producing a seismic intensity level (JMA) of 7 in Mashiki Town. Although the earthquake damage forecasting system in operation at the time predicted that this earthquake would cause no damage, it resulted in extensive human casualties and property damage centered in Mashiki Town. Past midnight on April 16, 28 hours after the first shock, the second and main shock hit, which recorded magnitude 7.3 and was the strongest recorded urban earthquake in Japan since 1995. The hypocenter extended from Kumamoto prefecture to Oita prefecture, cutting across the island of Kyushu. Mount Aso also saw increased volcanic activities which led to several landslides. This resulted in the collapse of the Great Aso Bridge, an important transportation point, causing the loss of human lives as well as obstruction of traffic for an extended period. Much confusion arose in the process of implementing measures in response to the earthquakes, which produced damage in urban areas as well as hilly and mountainous regions, raising many issues and prompting several new approaches.

Researchers in many fields have conducted various activities at the disaster sites in the one-year period following the earthquakes, and produced significant findings in many areas. In order to make these results available to the wider global community, JDR is releasing a special issue on the 2016 Kumamoto Earthquakes with excellent papers and reports to mark their one-year anniversary. While the submitted papers to this special issue went through our regular peer review process, no publication charge was imposed so as to encourage as many submissions as possible.

It is our hope that this special issue will contribute to throwing light on the 2016 Kumamoto Earthquakes in its entirety.