Hi Paul, Yes I am using the very  inexpensive $30?  DataQ 194   I am =
very happy with it, I actually use two of them for two different =
stations.  You can see my .gif's on the Psn new events page.  Ted
  ----- Original Message -----=20
  From: Paul Cianciolo=20
  To: psn-l@.................
  Sent: Saturday, April 21, 2007 1:38 PM
  Subject: RE: Time of Quake??


  Ted,

  Is it you that is using a DATAQ device...  ?

  a 154 or a 158=20
  PauLC

    -----Original Message-----
    From: psn-l-request@.............. =
[mailto:psn-l-request@................. Behalf Of tchannel
    Sent: Saturday, April 21, 2007 1:54 PM
    To: psn-l@..............
    Subject: Re: Time of Quake??


    Hi Chris, A question about P travel time?  I read somewhere it =
varies, from __km to __km per second.
    Does it vary depending on the material, type of earth, that it is =
moving through?
    I have calculated, from recordings, a range of 10,000 to 30,000 =
miles per hour. That's a big range.

    I would like to have a better understanding of it.   Thanks, Ted
      ----- Original Message -----=20
      From: ChrisAtUpw@..........
      To: psn-l@.................
      Sent: Saturday, April 21, 2007 9:34 AM
      Subject: Re: Time of Quake??


      In a message dated 2007/04/21, Paulc@........ writes:

         =20
        For the past month I have been working on a horizontal pendulum =
sensor and I am going through my maiden voyage with it.
            The clock is accurate to within 10 seconds, I am using the =
Amaseis program, and a 12 bit ADC.


      Hi Paul,

             The P waves may travel at 8.2 km / sec. You need your clock =
accurate to about 1 sec for practical purposes. I suggest that you keep =
a note of the errors for a day or two. They are often very large.
             You can buy a radio corrected crystal clock for less than =
$20. They are very useful and are accurate to 20 mS. They update every =
hour.=20
             You can also visit http://nist.time.gov/ and cross check =
on-line, but do watch out for transient data delays.


            I would like to try and compare events elsewhere in the =
world / country to my sensor. At this site I can see various locations.

        The question.

            If I know in  when in UTC an event occurred, and where.. how =
do I convert that to a UTC time when the event would arrive at my =
location, if ever.
        In other words how ho long does it take to get here??


         Y=20
        ou can calculate arrival time using =
http://neic.usgs.gov/neis/travel_times/=20


             and also download tables and charts to measure the distance =
from the P to S delay time.

             Regards,

             Chris Chapman








Hi Paul, Yes I am using the very  =
inexpensive=20
$30?  DataQ 194   I am very happy with it, I actually use =
two of=20
them for two different stations.  You can see my .gif's on the Psn =
new=20
events page.  Ted

  
----- Original Message ----- 
  From:=20
  Paul =
Cianciolo 
  
To: psn-l@.............. 
  
Sent: Saturday, April 21, 2007 =
1:38=20
  PM
  
Subject: RE: Time of =
Quake??
  


  
Ted,
  
 
  
Is=20
  it you that is using a DATAQ device...  ?
  
 
  
a=20
  154 or a 158 
  
PauLC

  

    
-----Original Message-----
From: psn-l-request@...............
=20
    [mailto:psn-l-request@...............On Behalf Of=20
    tchannel
Sent: Saturday, April 21, 2007 1:54 =
PM
To:=20
    psn-l@..............
Subje=
ct:=20
    Re: Time of Quake??


    
Hi Chris, A question about P travel =
time? =20
    I read somewhere it varies, from __km to __km per =
second.
    
Does it vary depending on the =
material, type of=20
    earth, that it is moving through?
    
I have calculated, from recordings, =
a range of=20
    10,000 to 30,000 miles per hour. That's a big =
range.
    
 
    
I would like to have a better =
understanding of=20
    it.   Thanks, Ted
    
      
----- Original Message ----- =

      From:=20
      ChrisAtUpw@....... 
      
To: psn-l@.............. =

      
Sent: Saturday, April 21, =
2007 9:34=20
      AM
      
Subject: Re: Time of =
Quake??
      

In a=20
      message dated 2007/04/21, Paulc@........=20
      writes:

    
      For the past month I have been working on a =
horizontal=20
        pendulum sensor and I am going through my maiden voyage with=20
        it.
    The clock is accurate to =
within 10=20
        seconds, I am using the Amaseis program, and a 12 bit =
ADC.


Hi=20
      Paul,

       The P waves may =
travel=20
      at 8.2 km / sec. You need your clock accurate to about 1 sec for =
practical=20
      purposes. I suggest that you keep a note of the errors for a day =
or two.=20
      They are often very large.
       =
You can=20
      buy a radio corrected crystal clock for less than $20. They are =
very=20
      useful and are accurate to 20 mS. They update every hour.=20
      
       You can also visit=20
      http://nist.time.gov/ and cross check on-line, but do watch out =
for=20
      transient data delays.


          I would like =
to try and=20
        compare events elsewhere in the world / country to my sensor. At =
this=20
        site I can see various locations.

The =
question.

    If I=20
        know in  when in UTC an event occurred, and where.. how do =
I=20
        convert that to a UTC time when the event would arrive at my =
location,=20
        if ever.
In other words how ho long does it take to get=20
        here??


   =
Y=20
      ou can calculate arrival time using http://neic.usgs.gov/nei=
s/travel_times/=20
        

      =20
      and=20
      also download tables and charts to measure the distance from the P =
to S=20
      delay time.

      =20
      Regards,

       Chris=20
      Chapman