3 Waves 



This chapter presents summaries of the wave data. A discussion of 

 individual major storms is given in Chapter 9 and contains additional wave 

 data for times when wave heights exceeded 2 m at the seaward end of the 

 FRF pier. Appendixes B through E provide more extensive data summaries 

 for each gauge, including height and period distributions, wave direction 

 distributions, persistence tables, and spectra during storms. 



Wave directions (similar to wind directions) at the FRF are seasonally 

 distributed. Waves approach most frequently from north of the pier in the fall 

 and winter and south of the pier in the summer, with the exception of storm 

 waves that approach twice as frequently from north of the pier. Annually, 

 waves are approximately evenly distributed between north and south (resultant 

 wave direction being almost shore-normal). 



Measurement Instruments 



The wave gauges included one wave staff gauge (Gauge 625), one buoy 

 gauge (Gauge 630), and two pressure gauges (Gauges 111 and 641) as shown 

 in Figure 2. Staff gauge 645 failed in May 1992 and was replaced by 

 pressure gauge 641 at the same location. The gauges were located as follows: 



Gauge Type/Number 



Continuous wire (645) 

 Pressure Gauge (641) 

 Continuous wire (625) 

 Accelerometer buoy (630) 

 Pressure gauge (111) 



Distance Off 



shore 



Water Depth 



Operational 



from Basel 



"ne 



m 



Period 



238 m 





3.5 



11/84-05/92 



238 m 





3.5 



11/92-12/94 



567 m 





8 



11/78-12/94 



6 km 





18 



11/78-12/94 



1 km 





8 



09/86-12/94 



Staff gauges 



One Baylor Company (Houston, TX) parallel cable inductance wave 

 gauge (Gauge 625 at sta 18+60 (Figure 2)) was mounted on the FRF pier. 

 Rugged and reliable, this gauge requires little maintenance except to keep 

 tension on the cables and to remove any material that may cause an electrical 



Chapter 3 Waves 



19 



