72 



Symposium on Microseisms 



f 



1 — i — - 





INPUT SHORTED 



•5 - .25 Seconds 



f^-AW^y^JjjflllL^^ 



l.oo - .5o 



1.33 - .67 



2.00 - 1.00 



/v^a/V^^ 



6.33 - 2.67 



10.00 - 5.00 



Figure 6. Mi crosei smic Spectral Analysis by Krohn-Hite Filter. Figures to the right of each 

 line give pass band of filter, but not of combined sei smometer- f il ter system. Large disturb- 

 ance on third line due to near approach at automobile. System gain reduced for longer periods. 



