Thanks for the answer Jim.

I suspected also that it was something to do with the geophone, but how
does the epoxy help? Tomorrow i can check a 10km distance station to check
if it also record something (which i dont believe).

Netherless i forgot to post the link of the SAC files, they can be
downloaded here:
https://dl.dropboxusercontent.com/u/15802004/sac.zip

Chris, in my case the geophone (1996 one) is inside a house, covered with
styrofoam.


2013/10/10 

> From: Jim ODonnell 
> To: psnlist 
> Sent: Thu, 10 Oct 2013 1:00
> Subject: Re: Please review these SAC
>
>
> Tiago- I call it a seismometer Burp (hiccup is good too)- happens with the
> 1 Hz phones, although I think all seismometers do it, but not as much.  I
> use 1 Hz phones in the desert for field work & in the summer they did this
> a lot, until I painted them with a white epoxy paint.
> You need another sensor recording nearby to see if the ground actually
> moved............    Jim
>
> Hi Jim,
>
>     Do you have any idea what is happening, please ? Maybe the top spring
> is expanding out of step with the bottom spring and buckling ? Are the
> geophones in direct sun light ? Are they the old type geophones or the
> redesigned newer ones ? White epoxy paint should reduce the amount of
> radiation absorbed, but it could also seal the unit completely. Have you
> tried wrapping them in Al foil to reduce absorbed radiation ? How about
> mounting them inside a Copper tube to slow down / prevent differential
> heating ?
>
>    Regards,
>
>    Chris Chapman
>
>
>
>
>
> ______________________________**____________________________
>
> Public Seismic Network Mailing List (PSNLIST)
>
> To leave this list email PSNLIST-REQUEST@.............. with the body of
> the message (first line only): unsubscribe
> See http://www.seismicnet.com/**maillist.htmlfor more information.
>
Thanks for the answer Jim.

I suspec=
ted also that it was something to do with the geophone, but how does the ep=
oxy help? Tomorrow i can check a 10km distance station to check if it also =
record something (which i dont believe).


Netherless i forgot to post the link of the SAC files, they =
can be downloaded here:
https://dl.dropboxusercontent.com/u/15802004/sac.zip

Chris, in my case the geophone (1996 one) is inside a =
house, covered with styrofoam.


=
2013/10/10  <chrisatupw@.......>=


From: Jim ODonnell <geophysics.jim@.........>
To: psnlist <psnlist@..............>

Sent: Thu, 10 Oct 2013 1:00

Subject: Re: Please review these SAC




Tiago- I call it a seismometer Burp (hiccup is good too)- happens with the =
1 Hz phones, although I think all seismometers do it, but not as much. =A0I=
 use 1 Hz phones in the desert for field work & in the summer they did =
this a lot, until I painted them with a white epoxy paint.


You need another sensor recording nearby to see if the ground actually move=
d............ =A0 =A0Jim



Hi Jim,



=A0 =A0 Do you have any idea what is happening, please ? Maybe the top spri=
ng is expanding out of step with the bottom spring and buckling ? Are the g=
eophones in direct sun light ? Are they the old type geophones or the redes=
igned newer ones ? White epoxy paint should reduce the amount of radiation =
absorbed, but it could also seal the unit completely. Have you tried wrappi=
ng them in Al foil to reduce absorbed radiation ? How about mounting them i=
nside a Copper tube to slow down / prevent differential heating ?




=A0 =A0Regards,



=A0 =A0Chris Chapman











__________________________________________________________



Public Seismic Network Mailing List (PSNLIST)



To leave this list email PSNLIST-REQUEST@.............. with the body of the m=
essage (first line only): unsubscribe

See h=
ttp://www.seismicnet.com/maillist.html for more information.