structural:summarization, structural:reformatting
Geologic activity

Being on the Ring of Fire, the island of Honshu is seismically active, and is home to 40 active volcanoes.

In 2011, an earthquake of magnitude 9.0–9.1 occurred off the coast of Honshu, generating tsunami waves up to 40.5 meters (133 ft) high and killing 19,747. It was the most powerful earthquake ever recorded in Japan, and the fourth most powerful earthquake in the world since modern record-keeping began in 1900. The tsunami subsequently led to the meltdown of 3 nuclear reactors at the Fukushima Daiichi Nuclear Power Plant, leading to the Fukushima nuclear disaster.