The Outline of the 1950-1 Eruption of Miharayama and a Review of the Works of Volcanologists with Reference to the Eruption

Abstract

The writer intended here to sketch in broad outline the eruption of Mt. Miharayama, on the island of Oshima, and to have a general view of the works of Japanese volcanologists with reference to the eruption.
The eruption was one of·the greatest activities of the volcano in the historical time, characterized by frequent explosions of the Strombolian type.
A summit eruption took place suddenly on July 16, 1950, ejecting ash and lava fragments and welling out molten lava, and continued without interruption until September 23. Besides, the volcanic activity resumed on February 4, 1951, and continued incessantly until about the end of March, but it declined and became intermittent at the beginning of April and was completely dead on July 28.
During the eruption, a large quantity of new lava flowed out over the rim of the central cone after an interval of 172 years.
Nearly one hundred able volcanologists In our country made various invaluable studies on the eruption from geophysical, geochemical, geological and petrological viewpoints.
Moreover, the eruption went a long way toward the popularization of scientific knowledge on the volcano and its activity.