100 



Symposium on Microseisms 



added to another disturbance with a period of 

 5.5 and an amplitude of 30. The individual 

 disturbances are represented by (A) and (B) 

 in the figure while the sum of the disturbances 

 is represented by (c) . A sample microseismic 

 record is included as (d). Although the values 

 taken for the simple cases were selected at ran- 

 dom a considerable parallelism seems to exist 

 between the composite record and the micro- 

 seismic record. 



Another interesting deduction can be made 

 from this construction. Although the original 



periods were 4 and 5.5, the most marked period 

 on the composite is 5 — representing neither 

 the shorter nor the longer wave. Moreover, 

 the amplitude, depending upon where and how 

 it is measured could be recorded as a value 

 between 39 and 43. 



It would seem from this, that if the reason- 

 ing has been valid to this point, much of the 

 microseismic data collected thus far are in- 

 consistent due to the fact that they do not 

 represent analysis into the component parts. 



Figure 3 



