the record corresponds to terminating the wave generation signal while 

 continuing to sample the waves. Squaring the standard deviation yields the 

 variance, which is theoretically equal to the total energy under the spectral 

 density curves. Note that tabulated standard deviations are within 

 approximately 5 percent of the square root of the energy levels identified in 

 Figures 12-9 and 12-10. Mean values reflect setdown of the water surface 

 profile near the breaker zone. Mean values from the wave and pore pressure 

 gauges are approximately equal because static pressures are not attenuated in 

 the water column or the sediment. 



Table 12-6 



Statistics of Wave Profile 4 and Pore Pressure Head 24 



File: A0618AHY.WRL 



Channel 



256-sec block 



Mean 

 ft 



Std deviation 

 ft 



4 



1 



-.592663 



.473351 



4 



2 



-.604135 



.505336 



4 



3 



-.591660 



.477283 



4 



4 



-.589063 



.485818 



4 



5 



-.589842 



.489397 



4 



6 



-.590401 



.501392 



4 



7 



-.604909 



.504524 



4 



8 



-.602705 



.493688 



4 



9 



-.596072 



.494718 



4 



10 



-.563763 



.242535 



24 



1 



-.570276 



.222024 



24 



2 



-.578107 



.236154 



24 



3 



-.568982 



.220605 



24 



4 



-.562733 



.228357 



24 



5 



-.565518 



.221738 



24 



6 



-.565460 



.227875 



24 



7 



-.577615 



.234550 



24 



8 



-.574427 



.234908 



24 



9 



-.567233 



.224543 



24 



10 



-.542446 



.117655 



Identification of marginal data sets. Pore pressure gauges which were 

 disconnected or removed from service are noted in Table 12-2. No other 

 marginal data sets are known at this time. 



252 



Chapter 1 2 Pore Pressure and Sediment Density Measurements 



