100 



0.06 



0,08 0.10 



Frequency ( Hz ) 



0.12 



Figure 47. Comparison of phase for frequency-matched MRS con- 

 stituents from three South Pass records. Uppermost 

 curve represents constituents which match paired 

 constituents from the other two records; starting 

 time of record is noted beside each curve. 



The preceding discussion invites some solid speculation. It is suggested 

 that each of the field records examined contains energy at a set of approxi- 

 mately 10, possibly more, discrete frequencies. These well-defined frequency 

 constituents are not independent, but are closely bound together in such a way 

 that their phase relationships relative to each other are nearly invariant in 

 time. The possibility of independent frequency constituents coexisting with 

 bound constituents is not precluded, but the bound system clearly appears to 

 be the major feature, accounting for most of the energy in the field records. 



The energy in each of the bound constituents varies tremendously over 

 short time intervals, as evidenced in the records of waves passing fixed 

 gages. The large and rapid variation is associated with striking variations 

 of wave grouping characteristics observed in the time series, variations which 

 have thwarted past attempts to establish empirical relationships for wave 

 grouping in field records. 



68 



