The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1902-06-03
CHAMBER CASES.
WEST INDIAN
VOLCANOES

The calamity which has just overtaken
Antilles will unquestionably lead to a fresh
discussion of the causes of volcanic dis
| turbances. All OF the phenomena involv-
ed therein are not yet fully understood,
ard corce'rnG some of them lierc are
perceptible differences of opinion among
experts. on ut least one point, however,
| there is general agreement At depth
OF about thirty miles the internal heat
Of the earth is probably great enough to
melt every known substance. Coni,ne-
ment may keep in a rigid condition the
material which lies beneath the solid
crust, but If an avenue of escape IS once
opened the stuff would soften and oozc
| upward. There is growing tendency.
moreover, to recognize the Importance OF
gravitation in producing eruptions. The
weight of several miles OF rock is almost
! Uncomfortable. and II certainly ought to
compel potentially plastic matter to rise
through any crevice that might be newly
formed. Russell, Gilbert and some other
authorities regard this as the chief me.
chancal agent in an eruption at least
when there is considerable outpouring
of lava.
As to the extent to which water oper-
ates there is some lack of harmony
among vulcanists. Shaler, Milne and 9TH
! ers hold that substance largely, II not
entirely responsible for the trouble. They
point to the fact that manv volcanoes
are situated near the sea coast of con-
tinents or on islands, where leakage from
the ocean may possibly occur Russell.
on the other hand, regards water not as
the initial factor, but as an occasional,
| though important, reinforcement He
suspects that when the molten rock has
70, 10 a II
tiers that fluid perhaps in a succession
| of pockets, and that steam is then sud
| denly generated. The explosive effects
which ensue are of two kinds BY the
expansion of the moisture which some
/ of the lava contains the latter is reduced
to state of powder and thus originate
the enormous clouds of fine dust which
are elected Shocks of greater or less
violence are also produced The less Sc
we're ones no doubt sound like the dis
charge of artillery. and give rise to trem-
ors in the immediate vicinity. In ex-
! IRENE cases enough force is developed
to rend the walls of the volcano itself.
Russell attributes the blowing up of Kra-
katoa to steam. The eliminating episode
of the Pelee eruption last week though
not resulting so disastrously to the noun
tain, would seem to be due to the same
immediate cause. To this particular ex-
poson, too, 1t seems safe to assign the
upheaval which excited a tidal wave.
The precise manner in which the plastic
material inside of the terrestrial shell
gets access to the surface is not entirely
clear. Nevertheless, 1t is possible to get
some light on the matter 1t is well
known that in many places there are deep
cracks, or faults in the earth's crust
Among the causes which led to their for
nation is the wrinkling of the exterior
of the globe when the interior shrank
30
be impenetrable, perhaps. Others in the
remote past have been wide and deep
enough to admit molten material from
| below The Palisades of the Hudson
are believed to have been formed by such
an intrusion, the adjacent rock on the
eastern face having since been worn away
by the weather or other agents. 1t has
been observed that many volcanoes are
distributed along similar faults. The ex-
istence of chain of volcanic islands in
10 West INDIES suggests the probability
that II follows a crack OF great antiquity,
though the issue of lava and ashes for
several centuries NAV have been limited
to few isolated spots Just how these
vents have been re-opened is one of the
most difficult Questions still left for in
vestigation. Given line of weakness in
the rocks, though and a Susceptibility to
fresh fracture Is afforded Professor Nc
Gee suggests that the overlooking Of the
ocean beu nv silt from the Mississippi
River or other sources NAV have been
the Immediately exciting cause OF the
recent outh-"ats other biologists have
found similar explanation acceptable in
the case of eruptions elsewhere The
theory has much to commend II to favor.
cable repair ship has ALREADY discov-
cred that the ocean bed. formerly 1000
feet below the surface. has recently sunk
almost 5000 feet more, Whether this in
cident Is cause or effect OF the vol
cano is question which the exrerts will
be asked to decide.-New York Tribune.