According to the Japanese government publication Rika-Nenpyō (理科年表) or Chronological Scientific Tables,[2] the epicenter was 40 kilometres (25 mi) south-southeast of Ishigaki Island with a magnitude of 7.4.

According to the Mamoru Nakamura Laboratory, University of the Ryukyus, the earthquake was due to the activity of the fault east of Ishigaki and it is estimated that the magnitude was 7.5.

[8] It has been estimated local agriculture was severely damaged because of sea water invasion and the population decreased to about one third of what it was before the earthquake.

However, taking into account the rough precision of the measuring instruments at this time and considering geomorphological parameters, the maximal run-up has been re-estimated to ~30m.

[8] There are many huge boulders on the coasts of the Yaeyema and Miyako islands that are believed to have been deposited by tsunamis.