Iowa state bystander. [volume] (Des Moines, Iowa) 1894-1916, 1913-12-12
|CITY FLAT TENANTS MAKES WATERMAN
Claimed Icebergs Have Heat;r,
Effect on Ocean.
Montreal Professor Bases His r,..
on Experiments In Bell. ,.,.
Straits - Water Chilled \.
berg Does Not Spread

ne oeliei mas long prevailed anon,
seafaring men that the approach y
icebergs could be detected by tho T.,
creasing chill Of the water sros
views were quite natural, for thsr
were assumed on the ground that N.
cooling influence Of the melting IL.
rendered the water ice cold. a COMA
ton which could be shown by tho =,
servation Of submerged thermomets,s !
Such beliefs are radically wror,
and If one is to believe the resu,ts -
observations taken by a Canadian po,N
eminent vessel during the past sum!
mer, theories concerning iceber,.
must be revised. 1t was found that
the water chilled by the berg does mt
spread outward. but owing to liz
greater density. sinks downward Th.
movement draws the surface vate1
toward the ice, and the surface cn,,
rents, not being cooled by normal yer
teal circulation, grow warmer as thew
near the iceberg. H. T. Barnes Of Mn Z
Gill University, Montreal, gives soma
further details of the work Of thu
steamer Montcalm, as follows: IN
Careful records were made Of thu
temperature effects of icebergs and
land. These tests have shown con,
clusively that it is the rise Of the tenn
perature which is the direct action Of
the melting iceberg, and that when 4
fall Of temperature is observed mean
ice, it is due to the influence Of cold.
er current from the north in which
the iceberg is carried. The cooling
influence of the ice itself is very
small.
"As a good example of how icebergs
and groups of icebergs affect the wa,
ter temperature, microthermogram
from the records which were obtained
in a westward passage through the
Straits Of Belle Isle shows that in
every case the approach of Ice caused
a rise Of temperature. d
"The explanation Of this iceberg ei.
feet was founded on Pettersson's the
DRY of ice melting in salt water. By
this theory, which can easily be veri.
fed by simple experiment. ice melt.
ing in salt water produces three cur !
rents; first, a current of sea water
cooled by the ice, which sinks down. /
ward by gravity; second, a current Of
warm sea water moving toward the
ice; third, a current Of light fresh \
water from the ice, which rises and
spreads over the surface Of the salt
water. En-
II at first thought that 1t was this 4
surface current of fresh water that H. \
fluenced the microthermometer in tho
actual sea tests. The fringe OF this
lighter water would be warmer than
the sea water on account d the action
of the sun and scattered radiation,
which is very strong at sea. The light
er water would retain the heat be-
cause it could not mix readily with !
the sea water. Near the iceberg 4
considered that a fall of Temperature 4
would result from the cooling ~
fluence of the surface current OF fresh n
er water. I
my recent tests have shown, now "
ever, that an iceberg melts so Slowly
that no effect of the dilution can % \
detected even right beside the bersT
Larger variations were found over Il
different parts of the sea than vers
obtained in the proximity of ice. q
my tests have shown that an ICE
berg probably causes only two OF 'ls I
Peterson currents-that is, colu
current sinking downward, carrying "a
with it all the melted ice water ana !.
horizontal surface current OF sea wa
ter flowing in toward the Ice to causs
its melting. BY this means we snou'u !.
expect the sea in the Immediate pioAi
nifty of icebergs to be warmer .uaa
farther away, because the sea su.ias ~. 81
current is moving inward toward wv 4
berg. and does not show IN the nor
NAL verticle circulation which 'enu. n
to keep the sea surface tempera'u'
cooler.
1T is interesting to find that an - Al Al
berg causes its own current OF ~ warm nnn n
er water, thus providing Tor ''s W.
destruction. Abundant evidence y :. u
hand to show the melting process -
ing on under the water line
Another interesting fact brougns ~ !, !.
by Mr.. Barnes is the large amour .ts, II
dissolved air in berg ice. Ice w. .sr.
made with bits chopped from s ueas n
effervesces, he says, almost hke a sss 4
water. He thinks that the 'ep ,.h
sudden sinking of the bergs WIZ :.
loud report may be due to t ~ ~, =; n. \
plosion from air pent up in tnen :
terror. 5i