The morning news. [volume] (Savannah, Ga.) 1887-1900, 1897-07-11
SUBMARINE EARTHQUAKES.
LandsIIps and Volcanoes PrOducs
Results Beneath the Oceans Sur.
face Similar 10 Those on Land,

Lahusups ana volcanoes Produces
Results Beneath the Oceans SURE
face Similar TO Those on Land.
From the London Standard.
Earthquakes formed an important topic
In the interesting lecture which Prof.
John Milne delivered to the Royal geo.
graphical society last night, though he
was dealing with the wider subject of the
changes which go on beneath the sea.
There was thus melancholy appositeness
in his remarks for each successive tele-
gram from India brings worse and worse
accounts of the recent seismic disturb
ance there. Large districts have suffered
more or less severely about Calcutta, Ma
dras, and Bombay, but the devastation in
Assam is now stated to be on far great
er SCALE and it is probable that the worst
is not yet known.
But Prof. Milne, as we have said, was
discussing a more comprehensive ques-
Ion-the movements that take place in
the silence of the central sea-" We have
long been aware that even here the earth
is not absolutely al rest, Tiny organisms
fall, like a perpetual drizzle, on the ocean
floor; earth dust, yet more minute sinks
gradually down through the water, but
this ooZe accumulates with extreme Slow
ness. Besides this, the floor itself may ba
uplifted or depressed, but these move-
ments also had been supposed to be very
gradual-So much so that they could nos
be detected, could hardly be inferred d-
rectly, from any observations made by
man. Prof. Milne, however, shows that
there are occasionally very significant
hints of what is going on, and that now
and then nature moves more abruptly
than some of us suppose Submarine ca
oles indicate unexpected disturbances
now the gutta percha is melted, as if by
heat; now the cable is broken, as though
by strain; now it appears to have been
buried by mud slip.
There are, it seems, two sets of causes
which produce movements beneath the sur
face of the sea. The one is the slow fold
ings, fractures and crushing of the crust
causes on land which have produced noun
tain chains, and are conspicuously record
ed on their rocks. The other is the eff
fects of erosion and sedimentation. The
removal of material from one place, as
from sea-worn coast, and the deposit oe
it in another, produce exactly the same re-
suit as the piling up of materials else-
where would do-namely, unstable cons
tours, which may ultimately cause move-
ments OF various kinds. In other words,
there may be iandslips below the water
Just as much as there may be above Il, and
from not dissmilar causes Both these
kinds OF influence probably affect larger
areas. There is a third, but more local.
lied, modifier of the ea-bed-the subma-
rine volcano. All three may produce
earthquakes, the first especially. Bent
rocks may at last break under the strain;
one or both parts of the divided mass may
start forward as 1t were, with a jumpi
myriads OF tons of rocks are set In mo-
ton, and a shudder is propagated through
the earth's crust, which. when ii orlgi-
mates beneath the ocean, may shatter cities
on reaching the land, and may raise huge
waves, that come sweeping along the coast
bringing death and destruction TO the low
lands. The first jerk may not be the only
one; again and again, II the crumpling pro-
cess continues, new slips may occur along
the line OF fracture, and fresh shocks DO
propagated through the crust.
on special object OF Prof Mines lee.
ture was 10 point out the circumstances
IN which these disturbances are most like
~ to occur. An earthquake and moye-
ment OF some kind stand In the relation ot
eHect and cause. Sometimes this move
ment Is Of an explosive character. and
the shock Is directly connected with vol-
cahic action, but-perhaps more often--ths
latter also stands rather In the relation
or consequence TO movements tending 10
wrinkle the earth's crust. Prof. Milne
during his residence In Japan-a verita-
Die land Of earthquakes-took some pains
70 ascertain whether the shocks were
started In tile mountain region or beneath
the sea, and found that out Of 4i9 shocks
less than one-siXth had originated I'M
land more than half beneath the ocean.
ana the rest near the coat, and even OK
these a good many had come from 70
sea. Besides this, he has observed that
wherever the land descends rapidly ne-
meath the surface OF the water, whether
from the coast line or into an ocean bisin'
there earthquakes are likely to originate,
while gentle slopes are rarely the sites
OF disturbance. Slipping OF materials o..
50 occurs much more easily in the former
ease 80 that here disturbances Of az
KINDS become more probable. In nc
northern part OF the Indian ocean there
". we may remark, a rapid deepening OK
the scaled and on either side much &C.
cumulation OF material. Whether the re-
cent earthquake has any connection Win
the swatch Of no rr0und" cannot nv
known till more precise details have been
received ana compared. but Prof Miin's
remarks on the general question SHOW
That this IL not impossible.