[2] An earthquake swarm is believed to be strongly related to volcanic activity on Miyake-jima.

When seismic activity began around 18:30 JST (09:30 UTC) on 26 June, the Japan Meteorological Agency issued a volcanic information announcement at 19:33 JST (10:33 UTC) on the same day, calling for caution regarding volcanic eruptions on Miyake-jima.

[4][5] From around 18:30 JST (09:30 UTC) on 26 June 2000, small-scale seismic activity began with the epicenter located in the southwest of Miyake-jima.

From late June to August, it became significant seismic activity in the waters off the west coast of Miyake-jima, as well as near Nii-jima and Kōzu-shima.

[2] The earthquake swarm caused collapsed houses and landslides on Nii-jima, Kōzu-shima, Shikine-jima, and Miyake-jima.