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forbi Spitsbergens Vestkyst. I den mod Øst gaaende Gren
synker Saltgehalten meget langsomt og jevnt, indtil den
ved Grændsen af det af Expeditionen undersøgte Felt har
naaet 3.50 °/0, medens den i clen nordover flydende Arm
meget hurtigt synker til endog under 3.45 °/0 for atter ved
Spitsbergens Nord vestkyst at hæve sig til lidt over 3.45 °/0.
Denne i Vest for Spitsbergen forefundne riuge
Saltholdighed i Overfladen er dog sandsynligvis kun
eiendommelig for den varmere Aarstid, da der fra Spitsbergens
mægtige Is- og Snebræer flyder store Mængder Ferskvand
ned i det tilstødende Hav.
Indflydelsen af saadant fra Kysterne udgaaende
Ferskvand indskrænker sig dog hovedsagelig kun til meget smaa
Dyb. da det saavel af disse som tidligere publicerede
Undersøgelser af samme Art fremgaar, at et over saltere Vand
flydende ferskere Overfladelag besidder en mærkelig Evne
til meget længe at holde sig forholdsvis ublandet, saaledes
at den fra Kysterne hidrørende Fortynding i Overfladen
ofte kan spores 30 til 40 Mile tilhavs, medens man ved
Bunden i Nærheden af Land ja endog i Fjordene kan finde
meget saltholdigt Vand. Denne Eiendommelighed træder
meget skarpt frem i Observationsrækken No. I til 8,1 da
Saltgehalten her fra Overfladen til 1 Favns (2 Meters) Dyb
tiltager med over 1 °/0, medens den siden temmelig jevnt
voxer med kun 0.06 °/0 for hver Favns Tilvæxt af Dybden.
De paa Spitsbergens Banker tagne Observationer viser da
ogsaa ganske rigtigt, at Vandet der paa Bunden i nogen
Afstand fra Land besidder en Saltstyrke, som paa sine
Steder enclog gaar op til over 3.50 °/o.
Paa begge Sider af den midt efter det norske Hav
flydende salte Overfladestrøm synker Saltgehalten paa den
ene Side mod den norske Kyst og paa den anden Side
mod den østgrønlandske Polarstrøm, en Synkning, som paa
Grund af de herskende Strømforholde hverken er jevn
eller regelmæssig. Saaledes flyder der fra Nordsøen langs
Norges Vestkyst i nordlig Retning en lidet saltholdig
Overfladestrøm, som ved den 62de Breddegrad, hvor Kysten bøier
nordostover, forlader denne, og fortsætter fremdeles i
nordlig Retning, indtil dens Virkninger i omtrent 40 Miles
Afstand fra Land efterhaanden taber sig. En mindre
udpræget lignende Kyststrøm gaar fra Vestfjorden udover i
sydvestlig Retning og naar ligeledes temmelig langt tilhavs,
førend dens Indflydelse paa Saltgehalten i Overfladevandet
fuldstændig forsvinder. Mellem disse Kyststrømme kaster
der sig en smal Arm af det saltere Atlanterhavsvand
forholdsvis nær ind under Land, hvor den meget skarpt
current flows in a north-easterly direction, as far north
almost as Beeren Eiland. where it divides into two arms,
one running east into Barents’ Sea. and the other in a
north-westerly direction past the west coast of Spitsbergen.
In the branch flowing east, the amount of salt diminishes
very slowly and gradually down to 3.50 per cent, at the
limit of the region explored by the Expedition, whereas in
that running north it rapidly sinks even below 3.45 per
cent, rising, however, on the north-western coast of
Spitz-bergen a little above 3.45 per cent.
This low percentage of salt in the surface-water west
of Spitzbergen is. however, in all probability the result of
summer heat, vast quantities of freshwater pouring down
to the sea at that season of the year from the immense
glaciers and snow-fields of that group of islands.
The effect of such an influx of fresh water from the
coast is. however, mostly confined to a very trifling depth,
the result of the observations taken on the Expedition, and
of others in connexion with the same subject previously
published, being to show, inter alia, that freshwater possesses
the remarkable property of floating on salt water for some
considerable time in a comparatively unmixed state, so
that its influence may be frequently traced at a distance
of from 30 to 40 geographical miles off shore, whereas the
bottom-water close in shore, nay that of friths and
estuaries even, often contains a very large proportion of salt.
This peculiar feature was strikingly instanced in the series
of observations from No. 1 to 8,1 the amount of salt at
the depth of 1 fathom (2 metres) exceeding that at the
surface by 1 per cent, whereas the subsequent increase
with the depth did not amount to more than 0.06 per cent
for every fathom. The observations taken on the banks
of Spitzbergen show that the maximum percentage of salt
in the bottom-water some distance from land, in certain
localities, reaches 3.50.
On either side of the salt surface-current flowing through
the medial portion of the Norwegian Sea. the amount of salt
diminishes, eastward in the direction of the Norwegian coast
and westward in the direction of the Arctic current ofi"
East Greenland; but this diminution, owing to the effect
of ocean currents, is however anything but regular and
gradual. Thus, for instance, a surface-current, with a low
percentage of salt, flows from the North Sea in a
northerly direction along the west coast of Norway, from which
it diverges near the 62nd parallel of latitude, continuing
on. still in a northerly direction, till, about 40
geographical miles from land, its influence gradually ceases to
be felt. Another coastal current, more limited in extent,
flows from the Vestfjord in a south-westerly direction,
its influence on the amount of salt in the
surface-water being likewise perceptible comparatively far out at
sea. Between these coastal currents runs a narrow arm
1 Disse Observationer kunne desuden ogsaa tjene som Bevis for
Fortrinligheden af den af Ekman angivne Yandhenter, som ved denne
Leilighed benyttedes.
1 These observations likewise attest the excellence of Ekman’s
apparatus for collecting sea-water, which was used on this occasion.
10:
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