Hi,

 

I have used the USGS Arrival Time Calculator to compare the amplitudes of
the past week to what I measure.  The 1 second amplitude I measure ranges
from almost perfect agreement on some events to about 1.6 times greater on
others and as bad as 1/7th predicted on others.  I use a 1 second high and
low pass filter and take the amplitude of the P grouping.  I have not
included the events in the shadow zone or events where I have a PKP and not
the P.  I understand this for a horizontal but I am using a vertical so
direction should not factor in.  Is this a normal range or do I need to look
for an instrument issue?  

 

Randy

 














Hi,

 

I have used the USGS Arrival Time Calculator to =
compare the
amplitudes of the past week to what I measure.  The 1 second =
amplitude I
measure ranges from almost perfect agreement on some events to about 1.6 =
times
greater on others and as bad as 1/7th predicted on =
others.  I
use a 1 second high and low pass filter and take the amplitude of the P
grouping.  I have not included the events in the shadow zone or =
events
where I have a PKP and not the P.  I understand this for a =
horizontal but
I am using a vertical so direction should not factor in.  Is this a =
normal
range or do I need to look for an instrument issue?  =


 

Randy