On December 16, 1707, scientists recorded the last confirmed eruption of Mount Fuji, Japan’s highest point. Fuji is composed of several overlapping volcanoes. The top two are known as “Old Fuji” (Ko Fuji) and “Young Fuji” (Shin Fuji). Fuji has erupted at various times starting around 100,000 years ago—and is still an active volcano today.

Fuji’s last eruption ejected tons of tephra into the atmosphere. Tephra includes all solid volcanic material—not lava or volcanic gas. Tephra released by the 1707 eruption of Fuji (called the Hoei eruption) included volcanic ash and volcanic rock, such as pumice and scoria. Tephra blanketed the city of Edo (now the central part of Tokyo, more than 100 kilometers (62 miles) away).

Japan is located on the most geologically active part of the planet, the Ring of Fire. The roughly horseshoe-shaped Ring of Fire circles the South Pacific, the eastern rim of Asia, and the western edge of the Americas. This region is known for its volcanic eruptions and earthquakes. Japan is no exception. Fuji’s Hoei eruption was preceded by a massive earthquake. The estimated-8.6-magnitude earthquake likely triggered a primed Fuji to erupt.

The damage—especially the deaths—from these disasters, plus a tsunami, is hard to untangle. But what can be attributed to the Hoei eruption is the damage to homes near Fuji. The tephra fallout also reduced agricultural productivity in the region, causing many people to starve to death.