I get the feeling the noise frequencies are being slightly
shifted or modulated in frequency or dampened alltogether
by the effects of the arriving wave.

This would mean the first arrival can be more subtle then I ever imagined.

Hard to detect.

geoff

----- Original Message ----- 
From: "Barry Lotz" 
To: 
Sent: Wednesday, September 02, 2009 6:54 PM
Subject: Re: ARRIVAL TIMES: Quiet Before The Storm


> Geoffrey
> I've also noticed this for quite some time. I thought it was my sensors. Maybe not.
> Regards
> Barry
> 
> 
> --- On Wed, 9/2/09, Geoffrey  wrote:
> 
> From: Geoffrey 
> Subject: ARRIVAL TIMES: Quiet Before The Storm
> To: "PSN-LIST" 
> Date: Wednesday, September 2, 2009, 5:50 PM
> 
> I have noticed in some Earthquakes you seem to notice
> a short increase in quietness just before the impulse arrives.
> 
> Is this a real phenomena or simply a coincidence ?
> 
> Does this mean the real arrival time is
> the beginning of the noticeable quiet ?
> 
> WHY THE QUIET ??
> What physics would possibly muffle the noise ?
> 
> arrival of Possibly eP instead of simply P ?
> 
> Also,
> 
> What is the preferred format for a PSN files data ?
> FLOAT or INTEGER
> 16 bit or 32 ?
> 
> My data is all 8 bit So should I expand it to
> meet the new format ?
> 
> Comments ?
> 
> geoff
> __________________________________________________________
> 
> Public Seismic Network Mailing List (PSN-L)
> 
> To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)