The process was probably
a gradual one of up-building, by means of which the sea receded as the
land steadily rose. Some idea of the mighty forces that have been at
work beneath the sea and above it can be gained by considering the
enormous mass of material now above the sea-level. Thus, the bulk of the
island of Hawaii, the largest of the group, has been estimated by the
Hawaiian Surveyor General as containing 3,600 cubic miles of lava rock
above sea-level. Taking the area of England at 50,000 square miles, this
mass of volcanic matter would cover that entire country to a depth of
274 feet. We must remember, however, that what is above sea-level is
only a small fraction of the total amount, since it sweeps down below
the waves hundreds of miles on every side.
CRATER OF HALEAKALA
Of the lava openings on these islands, the extinct one of Haleakala,
as stated, with its twenty-seven miles circumference, is far the most
stupendous. It is easy of access, the mountain sides leading to it
presenting a gentle slope; while the walls of the crater, in places
perpendicular, in others are so sloping that man and horse can descend
them. The pit varies from 1500 to 2000 feet in depth, its bottom being
very irregular from the old lava flows and the many cinder cones, these
still looking as fresh as though their fires had just gone out. Some
of these cones are over 500 feet high. There is a tradition among the
natives that the vast lava streams which in the past flowed from the
crater to the sea continued to do so in the period of their remote
ancestors.
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