Tides in the Mediterranean and Adjacent Seas 



385 



The computation made by Doodson and Corkan(1932, see alsoPROUDMAN 

 and Doodson, 1923) of the tides of the Irish Sea is shown in Fig. 161. Airy 

 had already found that the tides in the central part of the Channel, the actual 

 Irish Sea, have almost the character of a standing wave. The tidal current 

 changes nearly everywhere simultaneously, and the currents are strongest 



Fig. 161. Co-tidal and co-range lines of the M 2 tide in the Irish Sea. — , phase in degrees 

 referred to upper culmination of the moon in Greenwich; , amplitude in cm. 



where the range is smallest (in the St. George Channel and in the North 

 Channel), whereas the currents are smallest, even almost imperceptible, where 

 the range is largest (Isle of Man). This points unmistakably to standing 

 waves. The distribution of the co-tidal lines shows in the south an incoming 

 wave from the Atlantic Ocean, then a crowding of these lines, particularly 

 in the northern part of the St. George Channel; in the Irish Sea a large area 

 with nearly uniform time of high water (homochromy), which still persists 



25 



