Weather Explainers

On This Date: 1707 Hōei Earthquake Devastates Japan

On today's date in 1707, a catastrophic 8.6 magnitude earthquake hit Japan. This quake may have played a role in the last documented eruption of Mount Fuji.

Can an earthquake trigger a volcanic eruption? The answer, in certain cases, is probably, but only if the volcano is basically already primed to erupt.

One such occurrence happened 318 years ago on today’s date, when a catastrophic 8.6 tremor struck central Japan, becoming the largest earthquake in Japanese history until 2011, when it was surpassed by the Tōhoku temblor.

The massive 1707 quake occurred around midday and generated widespread devastation across multiple islands. The tremor claimed thousands of lives and reportedly destroyed tens of thousands of structures.

What made this earthquake particularly remarkable was its unprecedented scale and the simultaneous rupturing of multiple fault segments along the Nankai megathrust. The event triggered devastating tsunamis and massive landslides, including one enormous slide in Shizuoka that buried nearly two square kilometers under millions of cubic feet of debris.

The earthquake's impact extended beyond immediate destruction, as scientists believe it may have influenced volcanic activity in the region. Mount Fuji erupted approximately seven weeks after the earthquake, leading researchers to theorize that the massive seismic event created stress changes that affected the volcano's magma chamber.

This potential connection between major earthquakes and volcanic eruptions continues to be studied by modern seismologists.

The disaster was followed by significant aftershocks, including a magnitude 7.0 earthquake near Mount Fuji the following morning and another major tremor several months later off the Kii Peninsula. These subsequent quakes caused additional damage and demonstrated the long-lasting seismic instability triggered by the original event.

Senior writer Chris DeWeese edits Morning Brief, The Weather Channel’s newsletter.