1906. No. 3. AMUNDSEN’S OCEANOGRAPHIC OBSERVATIONS IN 1901. 91 
They also demonstrate what great changes may take place in the water- 
masses of these regions in the winter, and it furthermore seems probable 
that the position and extension of the area of formation for cold *Bottom- 
Water” may differ much in different years. 
Temperature and Circulation in the Bottom-Water of the 
Norwegian Sea. 
As no agencies exist which can lower the temperature of water at 
the bottom after it has once sunk below the sea-surface, whilst on the 
ather hand the internal heat of the Earth will raise its temperature very 
slowly after it has reached the bottom!, the lowest temperatures of the 
bottom-water will be most likely found near the region where it is 
formed; and this seems also to be the case actually. 
In the southern part of the Norwegian Sea, between Norway, Ice- 
land, and Jan Mayen, the temperature near the bottom, at depths of 2000 
and 3000 metres, is about —ı"ı° C. according to the observations made 
during the cruise of the “Michael Sars” in 1900. In the sea between Iceland 
and Jan Mayen and east of Iceland, the Ingolf Expedition found bottom- 
temperatures of about —ı'0° C. and —11° C. at depths between 1800 
and 2500 metres” At Station 18 of the Michael Sars, in 1900, 
between Iceland and Jan Mayen, the bottom temperature was —0"94° C. 
At Dr. Hjort's Stations 64 and 65 (in September 1900) west and 
southwest of Bear Island, the bottom-temperatures seem to have been 
about the same, or perhaps slightly lower? At Amundsen’s Stations 
15, 16, 20, and 23, where the observations go down to 2000 metres, 
the temperatures were lower, about —1-3° C. (according to the obser- 
vations taken with the most trustworthy instrument, Richter Reversing 
Thermometer No. 113) and the probability is that similar temperatures 
would have been found near the bottom“ It is therefore evident that 
the temperature of the bottom-water is appreciably lower at all depths 
L 2 
“Cf. Nansen, Oceanography of N. P. Basin, pp. 341 ef sg. 
See M. Knudsen, Hydrography, The Danish Ingolf-Expedition, vol. 1, No. 2, Copen- 
hagen 1899. | 
3 The temperatures were taken with the Pettersson-Nansen Insulated Water-Bottle, and 
cannot be corrected sufficiently accurately. 
4 Prof. Otto Pettersson believes (of. af. Geogr. Journal, vol. XXIV, p. 317) that the 
present writer’s assumption of a temperature for the deep of the northern Norwegian Sea 
of “probably about —1°3° C. or —1'4? C.” rests upon Mohn’s deep soundings in 1878, 
and is therefore uncertain. As is seen above, this is a mistake, the assumption in 
question rests upon Amundsen's observations, which are also the most trustworthy 
hitherto published from this region. 
