On 16th December 1707, Mount Fuji in Japan erupted. While this Hōei Eruption (as it became known) did not produce a lava flow, during its two week duration the eruption sporadically released hundreds of millions of cubic metres of volcanic ash into the atmosphere. This ash fell like rain on the nearby provinces of Izu, Kai, Musashi and Sagami, and witnesses recorded ash falling on Edo nearly 100km (60miles) away.

The eruption resulted in the opening of three new vents on the easterly side of the mountain and a small crater formed by a secondary eruption. Over the next year many effects of the eruption were felt including a flood of the Sakawa river caused by the fallen ash adding to the existing sediment in the riverbed. Mount Fuji has not erupted since Hōei, although it has yet to be declared inactive.