The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1896-06-13

evident that, if the lava is not in very
large quantity, it will become so
quickly cooled that it cannot flow far.
| The superheated steam which must
form will indeed penetrate it's sub
stance and reduce it's melting point, so
that it will creep further than it other
wise could down that slope of low
gradient; but after all it must harden
very quickly, and so become piled UP
in cone much sleeper than would be
possible on land. Gig. ID
OF course the emission of lava would
be intermittent, and in the intervals
between the eruptions or outfows the
old vents would become so sealed by
the chilling of the lava that new lateral
vents would be the rule, so that the
submarine mountain would gain in
breadth of base, although it would be
built always with very steep Sides The
building process will by and bye bring
the vent so near the surface that steam
explosions will be possible. The lava
will now be shattered, and, solidifying
from fusion still more rapidly than at
greater depth, will be piled in more
and more confused heaps, and more
and more steeply. Terrific explosions,
like that of the Krakatoa eruption, will
now be of frequent occurrence, assures
sometimes admitting volumes of sea
water to be flashed instantly into steam
and so in the midst of titanic battle
of Natures inanimate forces, an island
is finally born in mid-ocean-a con-
fused pile of smoking lava fragments,
cinders, sand and mud.
Again and again the newly formed
island may be blown to pieces, to reas-
sert its right to be, until at last a lava
conduit from the deep seated source to
the free air is established, so that the
lava wells up and overf1ows quietly
Now the island grows rapidly, as STRAIT
UNI after stratum is added to it's sur
face, and if the outflow of lava is free
as it has been in the Hawaiian volca-
noes, the result will be a symmetrical
low cone. When the lava reaches the
sea, OF course there will be cOmmotion
The platform it will build for a founda-
ton will be of a material more or less
fragmental and loosely piled together,
and the submarine wall must become
more and more nearly vertical as the
building process goes on. Gigs. 2, 81 |
You see what an insecure foundation |
the original portion at least of the ISL |
and must have, owing partly to the |
fragmental condition of the material |
it, partly to it's being piled |
up at so steep an angle, and further |
owing to the circumstance that the
buoyant effect of the water practically
reduces the specific gravity of the rock
at least one-third Now let us see if
we cannot explain some of the anon
allies [ have pointed out We can under
stand better, at any rate, how it hap
pens that the windward side of the ISL
and is so quickly and so extensively
Undermined. I remember how utterly
ncredulOus I was when first told that
he Hamakua and Hilo cliffs were be-
ieved to be due simply to the action of
he ocean swell. 1 could see that this
must mean encroachment of the ocean
half a mile or a mile into the base of
he mountain. Besides, there is deep
water, right up to the base of these
lifts. Now the action of sea waves
s ordinarily limited to a depth of a
ew fathoms only, so that as they eat
nto the land a platform is left, that
Tery soon prevents the waves from
breaking with any power directly on
he coast; they form instead fringe
If breakers at a little distance from
he shore. But grant that the compact
Of the island rests on
! comparatively loose heap of frag-
mental material, and you find no long
r difficulty in crediting the evidence 7
t your eyes. Gig. f.
Look now again at the great preei-
ice have spoken of on the windward
ide Of the Kohala mountain. Noticet
ext that this line of cliff is indented.
8 you can easily see on the map.
waves have the power Of cutting OF
oints and projecting angles Of land
hey do not form bays or reeesses s