PSN-L Email List Message
Subject: Re: L15B 4.5 Geophone, detecting teleseismic earthquake
From: ChrisAtUpw@.......
Date: Thu, 30 Mar 2006 21:57:46 EST
In a message dated 31/03/2006, jonfr500@......... writes:
Is it impossible for L15B 4.5Hz geophone to detect teleseismic
earthquakes or just improbable.
Hi Jon,
The sensitivity is down to ~1/5 at 2 Hz and it falls off increasingly
rapidly below this. At 1 Hz it is ~1/20. So what you can see depends on the P
wave frequency and on the magnitude of the quake. I would say that it may be
'difficult'.
It is possible to use a 'Roberts type' frequency compensating amplifier
to boost the output of a 4.5 Hz geophone fairly level down to ~0.5 Hz. This
enables you to use these geophones fairly well for teleseismic quakes.
Regards,
Chris Chapman
In a message dated 31/03/2006, jonfr500@......... writes:
<=
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style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
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impossible for L15B 4.5Hz geophone to detect teleseismic
earthquakes or=
=20
just improbable.
Hi Jon,
The sensitivity is down to ~1/5 at 2 Hz and it=20
falls off increasingly rapidly below this. At 1 Hz it is ~1/20. So what you=20=
can=20
see depends on the P wave frequency and on the magnitude of the quake.=20=
I=20
would say that it may be 'difficult'.
It is possible to use a 'Roberts type' frequenc=
y=20
compensating amplifier to boost the output of a 4.5 Hz geophone fairly level=
=20
down to ~0.5 Hz. This enables you to use these geophones fairly well fo=
r=20
teleseismic quakes.
Regards,
Chris Chapman
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