PETTBRSSON— INTRODUCTORY 



— VIII 



plateau between the Dogger Bank and Holland, the Atlantic Channel Stream 

 quickly loses its identity, as a mixed water is formed from the Atlantic water and 

 the river water flowing from the mouths of the Rhine, Scheldt, Weser and Elbe. 

 This can be seen from a comparison of the following hydrographical sections. 

 (Fig. 5 and 6)'. 



The German Bight and the south-eastern part of the North Sea between 

 Jutland and the Dogger Bank contain this water chiefly. It is only in the deep 

 guts and channels of the sea-bottom between the English coast and the western 

 slope of the Dogger Bank, that a communication takes place at times between 

 the Atlantic water on the northern North Sea plateau and the water entering 

 through the English Channel. Although the separate character and movement 



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Fig. 6 



of this water is difficult to determine, owing to the strong tidal currents in the 

 Channel, yet systematic temperature-observations have succeeded in showing, that 

 a true "Channel Stream" exists in the south-western part of the North Sea, 

 the velocity of which in October — November 1903 was estimated at 6 cm per second 

 or 5 km per day on the average 2. As the investigation of the movements of the 

 water in the southern North Sea may be expected to have great practical impor- 

 tance, because the migration of the young fishes and the fry of certain flat-fishes 

 seem to stand in relation thereto, stream observations in these regions, both in- 

 directly and directly (by current-measurers used on light-ships), are proposed. 



I The sections, wliicli are taken from the Bulletin of the International Study of the Sea for 

 Aug. 1903, Nov. 1903 and Febr. 1904, show that the Atlantic water (of over 35°/oo sahnity) occurs in 

 much greater mass at all periods of the year in the neighbourhood of the eastern entrance to the 

 Channel (Ostend and Orford Ness) than further to the east (Helder-Dogger Bank). 



= See: E. von Everdingen und C, H. Wind, "Oberflächentemperaturmessungen in der Nordsee" 

 Pubücations de Circonstance, Nr. 14. Copenhague. 1904. 



