SOMITE CENTRAL d'OCEANOGRAPHIE et d' ETUDE des COTES 



The Central Committee for Oceanography and Coastal Studies is a 

 French Governmental agency associated with the Naval Hydrographic Service 

 of the French Ministry of National Defense., In January 1949 this com- 

 mittee initiated the periodic issuance of an information bulletin. This 

 bulletin contains articles of general information on committee activities 

 and interests, technical communications in condensed form, and bibliogra- 

 phic notes. Distribution of this bulletin is limited and the Board takes 

 this opportunity to again brief some of the articles contained in the 

 bulletins to acquaint American students with the extent and character 

 of the coastal problems in other areas 



REMARKS ON WAVE FORECASTING 

 by Mo Gelci 



This article reports the results of the comparison between the 

 Sverdrup-Munk method of forecasting and the Jeffrey Suthons method of 

 forecasting, both being applied to the forecast of waves on the Morroccan 

 coast. As a result of several studies the following conclusions are 

 reached; (1) the measured amplitudes of waves, are approximately ten 

 times as large as those forecast| (2) the time of arrival of the waves 

 varies from 2 to 4 days earlier than forecast; and (3) the wave period is 

 forecast within an accuracy of 2 to 3 seconds. 



In an attempt to explain the differences which have been noted in 

 the comparison, the author notes that study of the weather charts indicates 

 that the isobars of the charts are not sufficiently precise, especially over 

 the ocean areas, to permit the prediction of the value of the wind velocity 

 with accuracy. 



He states further that it appears that in the actual state of African 

 meteorology wind velocities derived from isobars are probably not useful 

 because of their lack of precision for purposes of wave prediction. 



RELATIONS BETWEEN MICROSEISMIC ACTIVITY AND WAVES 

 by J, Debrach 



The study concerns principally the microseismic activity frequently 

 noted on seismograph records in the absence of any seismic activity on 

 land. The height of these waves is very small, being of the order of 

 several microns. The periods of the waves vary from about one second to 

 one minute but usually lie in the range, 3 to 10 seconds. It has been 

 noted that these seismic waves occur simultaneously over very large areas, 

 for example, occidental Europe frequently is the order of the magnitude 

 of the area involved. Several hypotheses have been proposed by numerous 



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