Kirk had written recently regarding the earthquake risk in Kumamoto being relatively high. This is likely due to the Tatsudayama fault (立田山断層), which runs directly under Kumamoto City. Info about this fault is hard to find, but in a nutshell, it’s one of a series of faults that stretch from Mt. Unzen to Mt. Aso. It last ruptured in 1882, resulting in a M6.3 earthquake, killing 20 people. Perhaps it is overdue. More can be found about the fascinating history of Mt. Kimpo (remember, it’s a dormant volcano, meaning it could erupt again!) at the link - Japanese only, but Google Translate is your friend. - William https://www.mifunemuseum.jp/kumamotogeo/kinpouzan.html