FIELDS OF FORCE AND OF MASS IN THE SEA. 



143 



downward the different deep pools are separated from each other. Finally, also, 

 the Norwegian Sea and the open Atlantic are separated by the Shetland-Faroe- 

 Iceland submarine ridge. 



The charts of fig. 28 show the mutual topography of the successive isobaric sur- 

 faces, the first six for the interval of pressure of 10, and the last six for the interval 

 of pressure of 100 decibars. The curves on these charts are drawn for intervals 1 

 dynamic millimeter. The curves along which the upper and the lower surface of 



Anomaly 

 ofsprot 



I0' 5 mfiort 



u 



J 1 I L. 



50 100km 



Fig. 30. Profile curves of isobaric surfaces and surfaces of equal volume anomaly. 



the sheets cut the bottom of the sea are drawn heavy. These charts show mainly 

 the same feature as those of fig. 27. In every sheet we find a general increase of 

 thickness as we proceed from Iceland toward Norway, and especially as we get 

 into the Baltic. Otherwise we recognize the same maxima and minima as in the 

 charts of fig. 27. Considered as representing the mass distribution, the charts 

 indicate greater concentration of mass where the sheets have their minimum of 



