J=C3=B3n Fr=C3=ADmann jonfr@.........
Subject: Recording earthquakes in a big city


Hello J=C3=B3n,
***It might well be that the smaller towns don't fit my plans. As I am
oing to try avoding owning a car in Germany.
he populations in the towns and cities are from 10.000 (Daun) and up to
 million (K=C3=B6ln).
    You are lucky. London is about 11 million and several UK towns=20
are about 1 million!=20
    How about using a bicycle for transport in towns up to 30,000?=20
Also, do check for any tram and bus services!
***But I want to know how it is to record a earthquakes in big towns. I am
urrently living in Denmark, in S=C3=B8nderborg. That town has a popluation
lose to 28.000 people. There is a lot of noise on my geophone. But I am
p on the 3rd floor (2nd floor danish system). So the results that I am
etting a bit noise because of this.
Does anyone here have experience on how to record earthquakes in larger
owns ? Is it possible to start with?
    In general it is usually quite possible, but maybe only well=20
away from heavy industrial plant, particularly ones using large=20
metal presses, rock crushing etc., but do expect the background=20
noise levels to be quite high. Road traffic, particularly heavy=20
lorries and goods trains generate quite a lot of noise, Uneven
-ness in the road, potholes, manhole covers, rainwater drain=20
grids can all interact with road traffic to generate pulse=20
noise. A heavy lorry with several axles driving over a depressed=20
drain or a pothole can generate a wave sequence which may look=20
like a P wave. =20
    The factor which concerns me more is your 3rd floor location. =20
Is there a bassement, or space on the ground floor for a geophone?=20
There are usually vertical colums extending through all floors to=20
carry water, drain pipes and electricity services. You may be able=20
to use one of these for a geophone cable? Buildings are relatively=20
light structures and react to wind noise, machinery and people=20
noise. The basement, or the ground floor if there isn't one are=20
likely to be the quietest locations.
    What sort of geophones are you using? I know that they are 4.5=20
Hz, but are they a triaxial type or a single axis vertical?
    Regards,
    Chris Chapman
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This is likely=20
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J=C3=B3n Fr=C3=ADmann jonfr@.........

Subject: Recording earthquakes in a big city





Hello<=
FONT size=3D2> J=C3=B3n,

***It might well be that the smaller towns don't fit my plans. As I am
going to try avoding owning a c=
ar in Germany.
The populations in the towns an=
d cities are from 10.000 (Daun) and up to
1 million (K=C3=B6ln).
    You are lucky. London is about 11 million =
and several UK towns 
are about 1 million! 
    How about using a bicycle for transport in towns up to 30,000? 
Also, do check for any tram and bus services!<=
/FONT>
=

***But I want to know how it is to record a earthquakes in big towns. I am
currently living in Denmark, in S=C3=B8nderborg. That=
 town has a popluation
close to 28.000 people. There i=
s a lot of noise on my geophone. But I am
up on the 3rd floor (2nd floor danish system). So the=
 results that I am
getting a bit noise because of =
this.

Does anyone here have experience on how to record earthquakes =
in larger
towns ? Is it possible to start=
 with?
    In general it is usually quite possible, but maybe only we=
ll 
away =
from heavy industrial plant, particularly on=
es using large 
metal presses, rock crushing etc., bu=
t do expect the background 
=
noise levels to be quite high. Road traffic, particularly heavy 
lorries and goods trains generate quite a lot of noise, Uneven
-ness <=
FONT size=3D2>in the road, potholes, manhole covers, rainwater drain 
grids can all =
interact with road traffic to generate pulse 
noise. A heavy lorry with several ax=
les driving over a depressed 
like a P wave.  
  =
  The factor which concerns me more is your 3rd floor location.  
Is there a basseme=
nt, or space on the ground floor for a geophone? 
There are usually vertical colums =
extending through all floors to 
carry water, drain pipes and electricity services. =
You may be able 
to use one of these for a geophone cable? Buildings are relatively =
light st=
ructures and react to wind noise, machinery and people 
noise. The basement, or the =
ground floor if there isn't one are 
likely to be the=
 quietest locations.
    What sort of geophones are you using? I know that they are =
4.5 
Hz, =
but are they a triaxial type or a single axi=
s vertical?
    Regards,
    Chris Chapman
<=
TT> 
 
<=
FONT size=3D2> 
 
 
 
 
=
 
 
 
=
This is likely 
 
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