1906. No.3. AMUNDSEN’S OCEANOGRAPHIC OBSERVATIONS IN 1901. 69 
In the maps for 300 and 400 metres, the isotherms of —1° C. and 
o° C. have very similar contours in the region of Amundsen’s Stations, 
as have also the isopycnals of 28'10 and 28'00; but the area of the 
cold heavy water increases with the depht so that the rings formed by 
the curves become wider. All traces of the cold surface-water have 
almost disappeared in these maps — except perhaps, to the north of Ice- 
land; — whilst there is, especially at 400 metres, an axis of cold bottom- 
water extending northwards, towards Jan Mayen, from the sea east of 
Iceland. 
In the maps for 50 and 100 metres, the cold Polar water of the 
upper layers, with temperature below o° C. and —1° C. and salinity 
below 349 and 348 %g, has a wide distribution east of the Greenland 
coast and north of Iceland. But in the region of Amundsen’s Stations 
the conditions are very peculiar, and there is an intimate connection 
between the cold water near the surface and the cold bottom-water. 
The isotherm of —1° C. forms a closed curve near Amundsen's region, 
in the map for 100 metres, and so does the isotherm of o° C. almost. 
The isotherm of —1° €. also encloses a special area in this region at 
50 metres, whilst the isohalines of 349 and 34'8 %/oo form peculiar 
tongues extending westward. The isopycnal of 28'00 forms closed 
curves or rings in both maps for 50 and 100 metres, but it is much 
wider in the latter. 
It is clear that there here is very nearly the centre of the region 
where the homogeneous bottom-water of the Norwegian Sea chiefly 
arises, and it is also clear that this bottom-water must be formed by 
cooling at the sea-surface during the winter, just as in the case of the 
bottom-water of the Barents Sea, described in the previons chapter. 
By examining the characteristic features of the vertical distribution 
of Temperature, Salinity, and Density in and under the waters of the 
North Polar Current, in the North Polar Basin and along the East coast 
of Greenland, it will easily be seen that the bottom-water of the Nor- 
wegian Sea cannot be water from this current, as was generally assumed. 
The Vertical Distribution of Temperature and Salinity in the East 
Greenland Polar Current and Underlying Waters. 
West of Amundsen’s Stations is the region of the East Greenland 
Polar Current, with very typical vertical distribution of temperature and 
salinity, of much the same character as found by the writer in the North 
Polar Basin, Near the water-surface there is a layer of Polar water, 
