FRF BATHYMETRY 9 JUL 84 



CERC PIEB 



Figure 43. Permanent trough under the FRF pier 

 (9 July 1984) 



comparison with prior years when the variation was observed to exceed 2 m in a 

 year. 



106. At 189 m, the depth variation exceeded 1.5 m.. The accumulation of 

 0.75 m of sediment during January was caused by erosion of the inshore. Wave 

 heights were relatively low during February and March, maintaining sediment 

 nearshore. The May survey was completed shortly after a mild storm which pro- 

 duced slightly above mean wave conditions. However, because of the abundance 

 of sediment at the time, significant erosion occurred. During the summer the 

 sediment was restored. A storm in October scoured the sediment from the 

 trough under the pier. Measured depth at the other positions on the pier 

 remained relatively constant. 



Bath3anetry 



107. Contour diagrams created from the data obtained during the bathy- 

 metric surveys are presented in Appendix C; characteristics of the bathymetric 

 conditions are discussed below. Figure 45 shows the locations of the surveyed 

 profile lines. 



108. The first survey of the year, completed on 5 January, showed an 

 asymmetric trough under the pier with an inshore end that elongated to the 



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