Hello all:

I have noticed that when P and S locations are calculated for events within a 
few hundred miles of my location (e.g., recent events in Quebec and Ohio) a 
Pb phase shows up that is 2 or 3 seconds ahead of the P wave arrival.  I have 
checked the books I have on hand and cannot find mention of a Pb phase.  It 
doesn't show for events that are thousands of miles away.  Can someone fill 
me in on this?

Thanks.

Bob Laney
Herndon, VA
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