Evening star. [volume] (Washington, D.C.) 1854-1972, 1949-12-02
'Lop-Sided' Earth Hinted
In Gravity Measurements
Figures Taken with New Type Meter
At Bases in II Nations
Bv Thomas r. Henry

At Bases in II Nations
By Thomas r. Henry
new concept of the shape Of the earth
may result from gravity measurements made
around the world for the Navy during the
past year.
The spinning globe may turn out to be
a tri-axial ellipsoid instead OF q spheroid, as
has been believed for the past century.
Gravity over large part OF the planet
now has been tied in directly with the as
certained value for Washington determined
by the Coast and Geodetic Survey. 1t was
impossible, however to make comparisons
with the world gravity center at Potsdam.
just outside Berlin, to which access was de-
MED by the Russians.
New Type Gravity Meter.
The measurements were made by DR..
George P. Woodland of the University OF
Wisconsin and were made possible by
new type Of gravity enthusiastically
weight attached to spring-which could
be carried easily In an airplane. Previous
gravity meters have required precise tenn
perature control, which, in turn, has made
heavy equipment necessary. 1t measures
the gravitational pull with an accuracy OF
one part in q million.
Measurements were made at the official
gravity bases Of IA nations and at about
20 subsidiary stations. Some noteworthy
differences from officially accepted figures
were found. especially in England. when
compared with the Washington station.
The shape of the earth is the major prob
lem involved It now Is considered as very
close to sphere with two major axes
one running north and south through the
poles and the other at right angles to this
in the latitude Of the equator. The second
is slightly longer than the first. There is
some evidence however. that the planet
may have third axis in the equatorial lat
itude. One may go through the center OF
the earth from some point in India to the
Pacific Coast of the United States. The
other. considerably shorter, may run from
the middle Atlantic to the middle Pacific.
Could Be Lop- Sided.
This would make the earth Unexpectedly
lop-sided. The truth Of the hypothesis may
be determined by analysis OF DR.. WOODLANDS
measurements.
It also may be possible to trace more pre-
cisely the earthquake lines Of the eartn.
There are believed to be two major lines
along which quakes occur. One starts on
the Pacific Coast of the United States and
runs through the Aleutians to Japan and
hence to the Philippines and the Dutch East
Indies, where it splits into two branches.
One runs southwark, probably through the
Antarctic continent. and thence up the west
coast of South America to complete the
circle. The other runs across the Central
Pacific. The second runs across the United
States Europe and Asia in about the lati-
tude OF Washington. It is Of quite second
AIRY Importance
These earthquake lines are believed to be
marked by notable deviations In the CRAWL
rational pull. \
Measurements at Sea.
-Four submarine expeditions have meas
ured gravity at sea of the two coasts OF the
United States, in the West Indies and on
northern South America. A notable pos
sible finding which awaits further study OF
the figures for confirmation, is that sharp
line can be drawn between the edges Of con-
tinents and sea basins The eastern shore
OF North America, for example. appears to
extend about 100 miles into the Atlantic
before real sea bottom starts. This stretch
periodically. from the geological viewpoint,
is above water and submerged.
It hitherto has been supposed that the
differences between the sea bottom close to
the shore and in the middle OF the ocean IS
due to deposits Of debris washed down from
the land. The Navy submarine explorations
indicate that the distinction is much more
fundamental. Ocean basin is always ocean
basin and continent always continent. There
Is a sharp gravity line between them which
can be determined rather precisely with the
new meters.
It Is proposed to extend the submarine
measurements to all the Atlantic and Pa
cif1c shores of North America.