Evening star., 1936-11-27
NAVY WILL PROBE
HOME OF QUAKES
Scientists to Make Tests
Undersea in Area of
Lesser Antilles.
Dy the Associated Press.

Dy the Associated Press.
A new undersea study Of earth
auakes and other geological phenom-
ena in the Caribbean Sea from Navy
submarine will be started Monday by
an expedition sailing from Coco Solo,
Canal Zone.
The U. S. S. Barracuda, commanded
BY Lieut.. w. A. CORY, will carry three
scientists on the five-weeks' cruise to
make so observations of the force of
gravity at subsurface points in a
Antilles Islands.
From these observations and depth
measurements made with sensitive
sound recorder, the scientists will study
the buckling and cracking in the
earth's crust beneath the seas in this
birthplace Of earthquakes.
Mountains Still Forming.
Capt. Lamar r. Leahy. Navy De-
partment photographer and director
Of the expedition, said the area to be
surveyed "is recognized from geo.
physical and geological standpoint as
one of the most interesting in the
world"
"1n this locality" Leahy said,
mountains are still in the process of
formation. earthquakes are frequent
and volcanoes have not yet achieved
stability"
The Caribbean has been the site of
previous similar studies and compari-
sons of the data obtained by the diff
ferent expeditions will provide addi-
tional information on changes which
have occurred.
The scientists scheduled to be aboard
the submarine are DR.. Maurice Ewing.
Lehigh University physicist: Lieut.. A.
j. Hoskinson. gravity expert of the
Coast and Geodetic Survey. and Dr.
Harry Hess. Princeton University
geologist.
Accurate Timing Factor.
Their scientific equipment consists
Of the depth finder and a delicate
gravity measuring machine contain
ing five pendulums attached to a
crystal clock, accurate to one two
thousandth OF second Recordings
Of the measurements made by the
gravity machine will be re-
corded on sensitized film by light
beams reflected from the swinging
pendulums. A further check on the
accuracy Of the clock will be provided
by special radio signals from the
United States Naval Observatory in
Washington.
The gravity recordings will be made
about 80 feet below the surface at
each Of the SO points. as the sub
marine moves slowly ahead The pen
dulums will be set swinging on their
knife-edge suspensions and the ma
chine will record their movements
automatically. The faster the pendu-
luns swing, the greater is the force of
gravity and the mass beneath them.
Rolls Equaiized.
II the submarine rolls or pitches in
the slightest degree. the pendulums
are so arranged that one is accelerated
by the same amount the other is re-
tarded. the movements thus canceling
each other and making the sole effect
that Of the earth's attraction.
'The purpose of making gravity
measurements at sea over these sub
merged ocean beds" Leahy said, lis to
gather data to determine the relative
stability and equilibrium Of the earth's
crust under the entire region Of the
Lesser Antilles Islands.
Where the earth's crust is settled
and stable, normal values Of gravity
are obtained, while in areas of large
disturbance, as over the ocean deeps,
outstanding Irregularities in gravity
values are encountered, which indi-
cate buckling and cracking in the
earth's crust"
The Bartlett Deep" south Of Cuba
and the Mares Deep north of Puerto
Rico have been prolific producers"
Of volcanic and earthquake disturb
ances, he said, and earthquakes are
evidence that mountains still are being
formed
The expedition, which is financed
except for the Navy's participation, by
the American Philosophical Society
through the American Geophysical
Union, will land at Philadelphia next
January a. Several months will be
required to analyze the records OBJ
tanned.