Mount Fuji Begins Its Last Major Eruption

Context

Japan in the early 18th century enjoyed relative peace under the Tokugawa shogunate, which had consolidated power after the turbulent Sengoku period and established a centralized feudal system centered in Edo. Mount Fuji, revered in Shinto and Buddhist traditions and visible from the capital, had shown no major activity for centuries, though minor seismic signals occasionally reminded residents of its presence in the tectonically active Ring of Fire. The broader society depended heavily on agriculture in the provinces surrounding the volcano, making any disruption to farmland a potential crisis for food security and social stability.

What Happened

On December 16, 1707, during the fourth year of the Hōei era, explosive activity commenced from new vents on Mount Fuji’s southeastern flank, ejecting plumes of ash, pumice, and scoria high into the atmosphere in a Plinian-style eruption. The event unfolded over several days, beginning with an initial earthquake and ejection of cinders that soon gave way to more intense discharges of rock and finer material; three distinct vents, later numbered 1 through 3, opened in succession. Ash drifted eastward, reaching the city of Edo roughly 100 kilometers away within hours and accumulating several centimeters thick in places, while provinces such as Izu, Kai, Sagami, and Musashi experienced heavier falls. The eruption continued intermittently through the winter, powered in part by the mixing of different magma types, and ceased on February 24, 1708.

Aftermath

Immediate effects centered on widespread agricultural damage as volcanic ash smothered fields and stunted crop growth across eastern Japan. Farmers in affected areas attempted to clear debris, but heavy rains in the following summer washed ash into rivers such as the Sakawa, creating temporary dams that later burst and triggered destructive floods and landslides on the Ashigara plain. Starvation followed in many communities, with the loss of harvests compounding respiratory difficulties from lingering ash; no precise death toll exists, but famine claimed numerous lives in the Fuji region and beyond.

Legacy

The Hōei eruption remains Mount Fuji’s last confirmed major activity, shaping Japanese understanding of volcanic hazards and prompting greater attention to land management and disaster preparedness in subsequent centuries. Its distinctive crater on the southeastern slope, now accessible via hiking trails, serves as a tangible reminder, while the event continues to inform modern geological monitoring and risk assessments for the densely populated Kanto region. Artistic depictions, including later works by Hokusai, further embedded the eruption in cultural memory of the volcano’s power.