Initial estimates of 605 km, based on four segments rupturing failed to explain tsunami deposits discovered at the western end of the trough.

Including an additional area at the southwestern end, part of the so-called Hyuga-nada segment, gave a better match, with a total rupture length in the range 675–700 km.

[16][17] Approximately 16 hours after the mainshock, in the early morning of the following day at around 06:00 JST, a strong earthquake with a magnitude of 7.0 occurred with its epicenter near Fujinomiya.

This earthquake was strongly felt in Kyoto (according to the "Diary of Miscellaneous Affairs") and Nagoya (as noted in the "Parrot Cage Records"), and it generated a tsunami.

In Kii, salt fields were flooded (according to the "History of Hainan Village"), and in Ise, it affected Yamada, Fukiage-cho, and Hitotsuboki, breaking the embankment of the Miyagawa River (as recorded in the "Jingu Bunko Manuscripts").

[20] Evidence suggests that changes in stress caused by large earthquakes might be sufficient to trigger volcanic eruptions, assuming that the magma system involved is close to a critical state.