Evening star., 1952-12-03
Interchange Of Oceans
5000 Years
Woter Rotation Is Measured
By Radioactive Carbon Count
By Thomos R. Henry

Dy NUOiOOCCiNe \OTDOn NOunC
By Thomos R. Henry
The sea turns somersaults every five
or six thousand years.
The cold waters of the Arctic and
Antarctic Oceans constantly are sinking
to the bottom and flowing southwark
along the floors of the Atlantic, Pacific
and Indian Oceans. When they reach
warm equatorial waters they tend to
rise to the surface and flow towards the
poles again.
What has been the bottom Of the
ocean becomes the top OF the ocean. The
process goes on interminably.
The rate of flow Of the cold water
southwark and northward long has been
q mystery. 1t now has approximately
been determined by measurements of
radioactive carbon in samples of the
deep water flowing from the Arctic. 1t
requires about 1900 years to get as far
south as the latitude of Newfoundland
and presumably several times as long
to reach the Equator.
The measurements made by DR..
Maurice Ewing Of Columbia University
are described by DR.. j. Laurence Kulp Of
Columbia, one of the country's foremost
experts in radiocarbon age determina-
tions in publication Of the American
Association for Advancement of Science
here.
Cosmic rays. continually bombarding
the earth from outer space, transmute
some of the nitrogen in the upper atmos-
phere to an unstable form of carbon
x,,;fI1 ho1 of of te1u nm
years. That Is, half Of any amount
originally present will disappear in this
period.
Carbon Indicates Age.
The radioactive carbon is mixed freely
with the carbon in the atmosphere and
is taken up by plants and by animals
that eat the plants. 1t remains with
them after they are dead, slowly becom-
ing less and less. Thus it is possible to
date human and animal bones and plant
remains for the past 10000 years with
considerable accuracy by the amount OF
the exploding carbon atoms which they
contain.
The same can be done with sea water.
DR.. Kulp explains in the American As
sociations monthly journal. The vari-
Gus carbon compounds IN the surface
weters have about the same radiocarbon
content as the atmosphere with which
they are in contact. Once this water
sinks to the bottom. however, there Is
NO way of repleniShing the supply. The
difference between the amount in this
bottom water and that in the surface
water Is a measure of the time that
has elapsed since the water sank.
The amount of carbon In ocean water
Is extremely small. It is necessary to
obtain about 200 gallons to get enough
for measurements to be made in the CO.
lumbia laboratories, DR.. Kulp says.
The rate of flow along the sea bottom
would depend in part on the amount OF
heat coming through the sea floor, and
this, in turn, would depend on the kind
of rock there. The measured speed, DR..
Kulp says, indicates that this cannot be
granite, as is the case with the conti-
nents.
The amount Of radiocarbon present in
the atmosphere depends on the amount
of coSmic radiation. Supposedly it re-
mains constant from year to year, but
some question has been raised whether
it may not have been more or less in the
distant past. If this Is the case, time
determinations by the carbon measure
ment would be partly invalidated.
Constant 5000 Years. ~
It now is fairly certain, DR.. Kulp says,
that the rate has been constant for
about 5000 years. Specimens of lumber
which have lasted for so centuries and
which can be dated by other means show
the right radiocarbon content. From
other evidence there Is good reason to
assume that there has been no notable
change for about 80, 900 years.
This technique of time measurements,
DR.. Kulp points out has been revolu-
tionary in archaeology.
1t has been possible to determine. for
example, that the LaScauX cave in
France, whose walls contain paintings
of the extinct woolly mammoth. was oc-
cupied by humans from 14,500 to 15,500
years ago. This is the oldest date thus
far found anywhere in the world for
objects associated with man.
Probably the most significant Bible
manuscript found In recent years is a
scroll of the Old Testament book Of
Isaiah discovered in Egypt Some ques-
tion was raised as to whether 1t might
not be a medieval forgery. The carbon
analysis showed that this was impossible.
date was fixed at somewhere between
B. c. and A. D.
Frozen in the earth of both Alaska and
Siberia are bison of a long g-extinct
species whose flesh still is in such an
excellent state of preservation that it can
be eaten by dogs-even by men. The
carbon dating Of one of these animals
shows that it lived about $4,000 years