446 Tides in the Mediterranean and Adjacent Seas 



that with a phase of 7 h at the opening, the inner basin will have a phase 

 of 1 h. There will be a nodal line in the Gorlo, i.e. the channel which leads 

 to the Barents Sea; owing to the increased friction at small depths and the 

 great current velocities, the standing wave phenomenon ends and changes 

 into a progressive wave. This seems to be confirmed by the observations. 

 In the principal inner basin, there are beside the co-oscillating tides, still 

 independent tides, which, according to the main direction of the basin, should 

 have a phase of around 7-5 h. With v = 05 the independent tide of a closed 

 basin becomes indirect, the northern basin will have the phase of 1 -5 h, the 

 southern basin a phase of 75 h. The superposition with the co-oscillating 

 tide in the northern section of the basin will then give a phase between 1 h 

 and 15 h. In the southern section the phase will be either 3| h in the Bay 

 of Arkhangelsk or 6-7 h in the Bay of Onezhskaya depending on the am- 

 plitudes of the components. The amplitudes will be small. This is also in 

 agreement with the observations; however, only an accurate computation of 

 each component and its superposition will tell whether this provides a found- 

 ation sufficient for the explanation of the tidal picture. 



21. The Tides of the North Polar Basin or Arctic Ocean 



The tides of this deep sea, which has a wide shelf extending in front of 

 its coasts — especially in nothern Siberia — with depths below 200 m and 

 mostly even below 50 m have aroused interest since early days. Already 

 Whewell (1833, p. 147) assumed that the tide wave enters the Arctic Ocean 

 between Greenland and Norway, travels as a progressive wave to the coasts 

 in the vicinity of the Bering Strait. Harris (1904-11) basing himself on the 

 very scarce observations available at that time, drew a chart of co-tidal lines 

 for the Arctic Ocean, which he completed and partly changed in 1911 in his 

 paper "Arctic Tides". This later chart of Harris shows the tide wave travell- 

 ing from the European North Sea between Spitzbergen and Greenland towards 

 the north-east keeping to the right side of the entire Arctic Ocean as a pro- 

 gressive wave up till the Bering Strait and then farther on to the Beaufort 

 Sea. It needs 20 h to cover the whole distance. A second weaker off-shoot 

 turns north of Greenland westwards, interferes with the wave coming from 

 the Davis Strait and Baffin Bay and forms, just in front of the northern coast 

 of Greenland, a small amphidromy rotating to the right. A vast area, how- 

 ever, remains uncharted; it may be the area where there was supposed to 

 be land. 



Fjeldstad (1923), using partly the observations gathered during the "Maud" 

 Expedition in the area of the north Siberian shelf, has made a new map of 

 the co-tidal lines. He too assumes a progressive wave coming from the 

 Atlantic Ocean between Greenland and Spitzbergen, and travelling to the 

 east coast of Siberia, thereby maintaining its direction. He leaves open a strip 

 immediately north of Canada for lack of usable observations. In the eastern 



