The Great Japanese Volcano Aso

The Mount Aso, or Aso-San, is a living volcano in the heart of the island
Kiushiu, Japan, whose peaks rise to a height of several thousand feet out of a
gigantic bowl. This bowl, which is many miles across, is an ancient crater
surpassing in size all other known craters nearer than the moon. Some 5,000
people, grouped in half a hundred villages on the old floor, are living today,
tilling the volcanic soil and trading in this vast crater, round about the
base of the new and ever-active cone that has risen in it.

Kiushiu is the most southern of the four main islands in the Japanese
archipelago. It is about 17,000 square miles in extent and is therefore larger
than Vancouver Island, or almost equal in area to Massachusetts and New
Hampshire combined. It is built up of very ancient rocks, both sedimentary and
igneous, belonging to the paleozoic and mesozoic eras, as well as of younger
rocks, and upon these as a foundation has been erected in more recent times,
partly during the age of man, a superstructure of volcanic materials which now
covers many thousand square miles, or about one half the area of the island.
It contains twenty volcanoes, counting two that are just off the coast to the
south, of which eight are now active. Among them Aso-san is on far the largest
scale, though now it is in a decadent stage and is surpassed in activity by
two or more of the others. Japan through all past ages has been a land of
extraordinary geological activity, possessed of a vital energy which,
continuing in force up to modern times, has been emphasized by the changes in
level of its coasts and heralded by its ever-vigorous volcanoes.