authors to explain the agitation As a result of the study made by 

 Mr. Debrach, he concludes that study of the micro seismic waves, -at this 

 time does not offer possibility of the use of such micro seismic activity 

 as a means of forecasting the occurrence of oceanic waves It does appear 

 however that microseismic waves may be useful in the consideration of 

 other data to be used in the forecasting of waves 



WAVE DIFFRACTION 

 by Ho Lacombe 



A comparison is made between the classical hydrodynamic methods of 

 studying wave diffraction and the optical methods of Huyghens,, The author 

 cites a number of studies which have been made on the diffraction of waves 

 and presents the results of a study which he has made comparing the Huyghens 

 method with the classical hydrodynamic method developed by Sommerfeld He 

 concludes that while further experimental verification is necessary, the 

 simple method of Huyghens gives results which are very similar to those of 

 the classical hydrodynamic method' and that the Huyghens method appears to 

 have certain advantages in that it is a much simpler method to use in cases 

 where the hydrodynamic solution may be extremely difficult,, He points 

 again to the need for considerable further study which he anticipates will 

 be very fruitful „ 



AN EXPLANATION OF CERTAIN MARINE CURRENTS 

 by M„ P. Antoine 



In the Mediterranean one often notes long tongues or bands of pale 

 green or pale blue water occurring in an area of deep blue water These 

 occurrences are noted usually after several days of high winds The ex- 

 planation of these bands may be discovered by observing the water immedi- 

 ately adjacent to a beacho One notes first a yellow area which contains 

 sand in suspension, followed to seaward by a green area which contains a 

 suspension, probably of very fine mud particles, this latter area grading 

 in color to the deep blue of the offshore waters „ Coastal currents push 

 this water along the coast Yvhen it arrives at a cape or other headland, 

 the currents continue their path at the surface essentially in a straight 

 line and thus form in the deep blue offshore water a tongue of green water 

 which often has advanced quite far from the coast „ Similarly when the 

 wind blows from the land and is canalized, for example by a valley de- 

 scending to the sea, this land wind then pushes before it the green water 

 of the coast which later becomes pale blue by dilution „ The author does 

 not believe that the change in color is due to a mixing of the blue water 

 but rather states the following explanation,, The action of wind is not 

 transmitted to the deep water by reason of the viscosity of the water s 

 therefore the currents must lie as a very thin layer on the surface of 

 the sea„ The coastal current and the suspended material entering the 

 deep water therefore occurs solely on the surface of the water and as the 



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