Internal Waves 



541 



Table 91. Internal waves in the Faero-Shetland Channel. 13-14 August 1910. 



"Michael Sars" station 1 1 5 f61°0W., 2°4\'W., 530 w <fep//ij, Scottish station Sc 



(Goldseeker) (6l°32'N., A WW., 725m depth) 



(According to Helland-Hansen) 



Depth 

 (m) 



Vertical Displacement 



Semi-diurnal 



Michael Sars 1 15 



17 (m) 



Phase 

 lunar h 



Goldseeker Sc 



?/(m) 



Phase 

 lunar h 



Diurnal 



Michael Sars 1 1 5 



?;(m) 



Phase 

 lunar h 



Goldseeker Sc 



tj (m) 



Phase 

 lunar h 



100 

 200 

 300 

 400 

 500 

 600 



18 



16 



9 



10 



5 



170 

 15-9 

 17-7 

 90 

 11-3 



39 



11 



8 



9 



6 



25 



12-3 

 14-7 



17-7 

 4.4 



5-2 

 1-2 



computed for station 115 (see p. 536 and Fig. 223), it is obvious that the dis- 

 tance of 106 km is so large, that the various waves arrive at the second station 

 with entirely different phases and, consequently, their final composition is here 

 of quite a different form. There exists, however, another possibility, which Hel- 

 land-Hansen stresses particularly; namely that, with the pronounced transverse 



<Chr 4 6 8 10 2 4 68 10 02 46 8 10 0246 8 10 024 68 10 



50 



E - 90 

 | 100 

 110 

 120 

 130 

 140 

 150 



Fig. 224. Depths of the isothermes 18°-24-5° from 12 February to 15 February 1938 at 

 "Meteor" Anchor Station 385. From 60 series with 1 h interval. 



slope of the isosteres (isothermes and isohalines) in the Faero-Shetland trough 

 periodical variations in the currents of the Atlantic Ocean may cause periodical 

 oscillations of the entire system in the transverse direction, which simulate 

 internal waves (see p. 537). In regions with strong horizontal gradients of 

 the oceanographic properties one is never quite certain if one has to deal 



