Japan leads the world in the total number of known volcanic eruptions (1,274) and in the number of volcanoes with historically recorded and dated eruptions (94). Japanese volcanoes are unusually explosive, destructive and deadly. The eruption of Mount Kikai was Earth’s second most explosive and largest eruption about 6,300 (radiocarbon dated) years ago. Explosive volcanoes also tend to produce large craters, huge calderas and their eruptions are often accompanied by pyroclastic flows. Japan’s Kussharo, Aira, Aso and Akan calderas are the first, second, third and fifth largest in the world.
A record 28% of the eruptions of Japanese volcanoes are followed by pyroclastic flows. These are spinning mixtures of obsidian, ash, pumice, and cinders, very hot gases that flow down the side of the volcano at speeds over 200 kilometers per hour and at temperatures sometimes over 350 degrees Celcius. Japan is among the top three regions to have suffered the largest number of human deaths (238,867 lives) from the eruptions of volcanoes, after Indonesia and the Carribean region. Unzen’s eruption in 1792 was fifth deadliest eruption in the world killing 15,000 people (after Tambora, Indonesia; Krakatau, Indonesia; Mt. Pelee, Martinique; Ruiz, Colombia). Mount Fugendake’s pyroclastic flows in 1990 killed over 15,000 people. Mount Sakurajima is one of the longest erupting (decade) volcanoes in the world. It is also one of the most active volcanoes in the world, erupting about 150 times a year frequently dumping its ashes on the city of Kagoshima.
Like elsewhere in the world, people in major cities in Japan such as Tokyo and Kagoshima, continue to live in shadow of very deadly volcanoes. The Japanese, as in ancient times, today celebrate the beauty and sacredness of their mountains in art and literature. But they also take to the mountains for resort living or to climb or hike the many highlands. Mount Fuji is Japan’s highest (3,776 m) and most sacred mountain since ancient times. Famed for its near-symmetrical conical peak, it is a landmark and symbol of Japan and the most photographed mountain in the world.
Known as the “Roof of Japan”, the Chubu Region in central Honshu has many peaks reaching 3,000 m high. Mountain ranges such as the majestic Japan Alps, form natural barriers or divides, making it difficult for people to travel throughout the country. They also hindered efforts at national integration during ancient times. In modern times however, Japanese people have been able to overcome some of these natural barriers by resorting to air travel and by building bridges and tunnels, such as the 11-km tunnel between Tokyo to Niigata prefecture passes through the mountains.
Although the ruggedness of the land has made farming difficult, Japanese people have successfully cultivated crops such as rice and tea by terracing the mountains. They have also benefited by building hydroelectric power dams to harnass the energy from the fast-flowing rivers that cascade down the steep mountainsides. Hotsprings and geothermal energy plants are other benefits tapped by living among volcanoes.