FRF BATHYMETRY 13 JAN 83 



CERC PIER 



Figure 42. Permanent trough under the FRF pier 



occurs as far away as 300 m, and the shoreline may be affected up to 350 m 

 from the pier (Miller, Birkemeier, and DeWall 1983). 

 History of bottom elevations 



105. Useful for interpretation of the wave data, a history of the bot- 

 tom elevations is presented at the Baylor wave gage locations, pier sta 6+20 

 (189 m) and sta 19+00 (579 m); histories at intermediate locations at 323 and 

 433 ni are also included (Figure 43). Variations of elevation under the pier 

 are due to natural processes (such as profile changes due to bar movement) as 

 well as scour due to the interaction of the pier piles with waves and cur- 

 rents. At the beginning of the year, the scour hole at the seaward end of the 

 pier was 8.5 m deep. Following a storm in late January, the scour hole deep- 

 ened to 9 ni (measured during the 8 February survey). However, the scour hole 

 rapidly shoaled to 8 m by late March due to unseasonably mild wave conditions. 

 The scour hole, slightly less than 8 ra deep, remained stable through the 

 spring and summer. Tropical Storm Dean (28-30 September) caused 1 m of ero- 

 sion in the scour hole as measured in the 1 October survey. By the end of the 

 year sediment had again accumulated, and the depth was 8 m. 



106. At 189 m, the depth varied more slowly with the seasonal trends in 



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