Atlanta tri-weekly journal. [volume] (Atlanta, Ga.) 1920-19??, 1922-12-26
SCIENTIFIC TESTS
MAY DETERMINE
CAUSE OF 'QUAKES
Atlanta Journal News Bureau,
408 Evans Building.
BY THEODORE TILLER

calamities in Chile and elsewere
within the past few weeks have
stirred the United States govern
ment to it's first intensive investiga-
ton into the cause of such uphea-
walls. In collaboration with experts
of the Carnegie institution, who
have been. studying this battling
question for many years, the hydro,
graphic office of the navy depart
ment intends to take approximately
seven thousand soundings along the
Pacific coast between San Francisco
and Point Descanso, Mexico.
Two destroyers, the Hull and
Cory, are now equipped at San
Francisco with special apparatus to
measure the ocean depths of sound
waves. They will make complete
maps of the ocean bottom of the
Pacific and by comparisons hope to
find data revealing the reason for
upheavals of the earth.
Depth Recorder
Tests with the so-called sonic
depth finder, which has taken
and is virtually unlimited in oper-
atoms, were made first by the de-
stroyer Stewart and led to the in
terests of tn eCarnegie in applying
this test to the riddle of earth
quakes and their causes.
Directors of the Carnegie Instf-
tute believe that the successive, Sc
we're earthquakes, which have
caused so much fear and suffering
on the Pacific coast undoubtedly
have their origin in the suspected
receding movement of the contig-
uous coast of California" according
to the announcement of the navy
department.
"Much has been written on this
subject but up to quite recently no
one was in a position to investigate
the underlying causes. The Carne-
gle Institute and the photographic
office of the navy department have
studied the possibilities of the sonic
recorder and both believe that de-
velopments of great Importance will
result from the work now begin
ming.
1.-Two methods of obtaining sound
ings will be used, ONE for depths up
to 90 fathoms and the others for great
err depths. The first methods known
as the angle method uses the ship S
nropellers as a sound source, and
the echo is received in the compen-
sator from the sound receivers. The
depth scale is graduated by obtain
ing a. number of points on the curve
when the set is calibrated. After
directly off the scale.
1.-The second or deep sea method
uses the speed of sound in water
as a. means of obtaining the depth.
An impulse is sent out on the oscll'
lator and the elapsed time between
the sending and receiving OF the
oscillation is automatically recorded
when the echo completes the electrl-
cal circuit
Special Process
1t cost $4,000 for the installation
of each depth finding equipment. IN
the destroyers. 1t would take three
hours to get a single sounding at the
depth of 1900 fathoms using the
old method of dropping the lead.
The new method takes but tour
minutes and the results \are even
more accurate. Lieut.. Commanders
r. II. Bierd, of the Cory, and s. +.
Helm, of the Hull, are in charge or
the sounding expedition, While
Prof. Lawson and Willis have been
assigned from the Carnegie lnstt'
tute.
"The soundings," said the navy
announcement, will be run on par
allel lines approximately at right
angles to the 1000 fathom curve at
intervals of five to ten miles extend
ing from as near the shore line as
possible to the floor of the Pacific.
After obtaining these soundings a
man of the continental shelf from
the shore line to the floor OF the
Pacific will be developed"
The Sea Bottom
The Stewart in testing the SOUND
ing device recently cruised from
Newport, r. l., to Chefoo, emma
via. the Mediterranean and suck
making the run to Gibralter In n1he
DAYS, taking over 900 soundlngs
while moving at Is knots, Intervals
between soundings varying from,
to 20 minutes. An outline OF the
bottom of the sea was accurately re-
corded in this trip.
1.-THE sea bottom there was found
to consist of an extensive plane
bordered by mountains and table.
lands" the navy states, some OF
which rose 1000 feet above the
plane. Several deep depresslons
none of which are shown on charts
were also discovered. The eXplora-
ton of all the sea floor is possible
by the use if this new device when
bids fair to revolutionize plotting
and navigation.
Harvey C. Hayes, PHYSICIST OF the
Tinted States naval engineering eX-
neriment station at Annapolis is the
designer of the device.
FIGHT Over Custody