It is hypothesized that the Hōei eruption was due to two earthquakes, namely Genroku and Hōei, with a magnitude of 8.2 and 8.7. The former took place in 1703 at the Sagami Trough while the latter occurred in 1707 at the Nankai Trough.
Researchers propose that the Hōei eruption was triggered by two significant earthquakes, Genroku and Hōei, measuring 8.2 and 8.7 on the Richter scale. The first earthquake happened in 1703 at the Sagami Trough, followed by a second earthquake in 1707 at the Nankai Trough.