The Hawaiian gazette., 1902-08-05

inEton star. IN which its Homo
lulu correspondent. Rev. Or. :
r. Bishop. writes of the harmless
habits OF Hawaiian volcanoes. is good
matter to cut out and send to appre-
hensive friends abroad:
4 HONOLULU. June 2o-The object of
the present letter rs TO present facts well
known in Hawaii which may tend to allay
the entirely uufounded fears of many
tourists who We learn have lately been
deferred from enjoying the many great
attractions of our lovely islands by the
presence of our volcanoes. The fearful
explosion of Mount Pelee at Martinique
destroying in a moment an entire city of
900 people, has naturally enough kin
died horror OF volcanic action OF
course II lis not strange, nor absurd, II
such a horror should become almost hys-
teric in some persons Probably We have
no cause to be surprised, although We are
so. that We hear, very extensive
dread has infected the stream of tourists
about visiting our volcanic islands.
These fears have taken two directions,
as indicated by the San Francisco papers.
both of which i would discuss. One re
lates to a fancied danger to the city Of
Honolulu as being located at the base of
two recent volcanoes. The other Is the
alleged terribly menacing action of our
very tame and friendly volcano, kilauea,
which we count upon as the most inter
esting of our attractions for tourists. In
treating OF these matters ! may be in
dulged in claiming some title To hear
ing, as being by no means a tyro, but
having studied and written for many
years past on volcanic subjects. Among
the writings are two small pamphlets
one a prize essay on the Red CLOVIS from
Krskatoa, the other an article on the
geology of Oahu, with an appendix on
1.-THE Brevity OF Tuff-cone Eruptions."
which last was just published in the Am
erican Geologist January 1901.
( HONOLULU NOT DANGEROUS.
! TO begin with the alleged dangerous
neighborhood of Honolulu. Diamond Head
and Punchbowl, so conspicuous In our
city, are not properly volcanoes at all, but
J "tuff-cones, produced by volcanic ex
blossoms Icing ago, lasting only few
minutes. az | demonstrated in the last
named appendix. The accurately circular
rims of these two bowls proves that the
whole of their explosions of hot mud,
shot miles aloft, lasted for very brief
space, and then ceased entirely and for
ever, having piled up their huge and
stately mounds. Their presence furnished
no ground of apprehension, any more
than would the pit left by an abandoned
powder magazine after blowing up.
But one may ask, How do you know
that similar volcanic explosions are not
likely to occur AGAIN." ] answer, we
know ii simply on very strong grounds of
probability. This island of Oahu is com
posed of two extremely ancient volcanic
ranges both having been originally huge
domes, such as the still active Mauna Loa
now is, 200 miles away. All volcanic ac
ton ceased on Oahu probably one million
years ago. since when atmospheric erosion
has gnawed out and weathered away
three-fOurths of their bulk, leaving only
the skeleton ribs of their once comeiy
shapes. During the same lapse OF ages
these mountains have slowly subsidized in
to the ocean depths some thousands of
feet. This is proved by artesian well Dor
ings through both lava and coral far be
low sea level. In one instance, near Dia-
mond Head continuous strata of coral
were found at the depth of 800 feet.
And coral grows only near the surface of
the sea The island had sunk at least
800 feet.
During all that million years there was
left no trace Of volcanic activity until
comparatively recent period, when a
large number of tuff-cones Were thrown
up. chiefly around the coasts of the ISL
and. That they are thus recent as com
pared with the immensely eroded hard
mountains is proved by the comparative
ly slight erosion of these cones, although
composed of the very soft tuff rock,
which is a cement of hot mud, rained
down from aloft, and entirely diff rent
from the very hard lava, which H.ll,d
up from below and streamed in burning,
viscid rivers over the ground.
CAUSE OF LATER OUTBURST.
Now, what was the cause of that later
outburst of volcanic activity which pro-
duced Punchbowl, Diamond Head and
dozen sister cones in this region? Jfeie
seems to be the strongest reason to con-
meet 1t with a widespread disturbance of
the earth's crust, due to a sudden break
ing up of the continental ice caps at the
close of the glacial period. 70 similar
commissions from the same cause have
been attributed those enormous lava
floods which invaded Oregon and Caller
mia at recent period. 1t is probable
that the great cataclysm known as the
deluge was due to the same widespread
convulsive disturbance.
Any similar CONFUSION If the ta"th's
crust is wholly unlikely to occur unless
another ice age should superv IN, r1cli-
plying myr:ads Of years in its progress.
Hence We may count OU.Je!ves entirely
safe on Oahu from any no = volcanic oX-
plosions. On rage Is }: my ie"ogy ,f
Oahu" | have made coniec,Gral csti-
mate of the age of PunGhbowl at $500
years and the Diamond Fad AZ Lao
years. This is but somewhat crude guess
work. But we seem to have good reason
to feel safe from any recurrence Of the
commissions which 90 long ago thr,V ZIP
these brown and pictur,s lue monsters u
diversity the scenery ut our city. Punch
bowl constitutes sort Of Einel tower
800 feet high to whose summit you can
drive to survey the city. \ mic AMI a
half inland ons reaches on altitude Of $40
feet on Pacific Heights Dv electro 'aii-
way, whence you can look down into the
symmetrical bowl which is half mile
in diameter
But how about danger from the active
volcanoes of the Island of Hawaii, over
200 miles dis ant rom lIolululu IS the
bird flies? Is there no danger in visiting
them? one of them, Iiilauca, We count
upon as our chief attraction II 6ntice
tourists hithes, as being the most stupon-
dous exhibition Of fiery forces or tne
globe, as far eXCee ling Vsslvius or Etna
ns, Niarara aLiilaas