The Chickasha daily express. (Chickasha, Indian Territory [Okla.]) 1899-current, 1916-03-11
Panama Canal Will Not Be Swallowed By
Quake or Destroyed By Slides,
Says Expert Of Mines
Bureau
lSTHMUS is RISING
AS OCEAN BED SINKS
Movement Not Rapid Enough to Cause
Trouble; Walls Of Culebra Cut Weak
in Places; Gatun Dam
viii Hold
BY United Press.

BY United Press.
WASHINGTON, d. c.. March IL
That the Panama canal will not be
swallowed up by an earthquake in the
future and that the troublesome slides
now being encountered will eventually
be conquered and the great waterway
made an unqualified success, is the
opinion of Donald F. Macdonald, for
merly geologist and now mining geol-
ogist for the United States bureau of
mines.
Mr.. Macdonald, who spent several
years on the isthmus making a care
full study as to frugality of the earth's
crust, has just made an official report
to the effect that, while through seis-
mic disturbances the whole isthmus
is rising at the rate of three feet every
hundred years, this will not necessar-
lily injure the canal. As far as he
sees. it will merely mean a little adj
ditional expense in the dredging of
the big waterway. The cause of this
rising, he says, is the sinking of the
ocean bottom outside the isthmian
shore waters. Every time there is a
little movement of the ocean bottom,
the isthmus, to be in harmony, joins
in. He also suggests that if the ris.
ing motion be rapid, then there would
be serious danger for the canal, but,
that from what has happened in re-
cent geologic time, 1t may be con-
cluded that the canal is not in any
appreciable danger from the instability
of the isthmian land The rising of
the isthmus. however, has been re-
sponsible for the many slides that have
been encountered, in that the motion
OF the ground has dislocated and crush
ed the rocks, leaving them weak and
unstable.
AT any rate" says Mr., Macdonald,
so far as the digging of the Culebra
cut is concerned, these faults have in
creased the cost of the canal several
million dollars.
'As to the slides, Culebra cut is
a vast ditch that passes through many
varieties of rock in the nine miles OF
its length. Some of these are weak
and unstable. and where the slopes
of the cut were steep and 100 to 300
feet high the weaker rocks crushed
down to flatter slopes. Whenever the
slope got flat enough, the sliding stop
ped. At no time did the engineering
staff constructing the canal believe
that the slides were menace to the ul-
innate completion and successful oper-
alton of the canal, in spite of the fact
that at times they were somewhat
troublesome They have made neces-
sary the excavation of about 3O,000,0O0
cubic yards more than was included
N the first estimate for Culebra cut.
but they have not in the past and will
not in the future endanger the ultimate
success of the canal"
Mr.. Macdonald calls attention to
the fact that one is apt to forget that
the greatest variation OF atmospheric
pressure near sea level may be more
than four million tons per square
mile and that if the adjustment of at
pressure. in very large
cave or mine lags behind any quick
in atmospheric pressure at
the surface. a considerable strain may
be added 10 the roof Of such an exca-
walton. Discussing the real cause Of
the slides. Mr.. Macdonald declares
that in many cases the immediate
cause was the oversteepness and
height of the slopes. the blasting and
other work attributable only to man.
He adds that the geologic conditions
were not sufficiently considered in the