PSN-L Email List Message

Subject: Re: low pressure tilt?
From: ian ian@...........
Date: Mon, 10 Mar 2008 20:41:05 +0000


Hi,

I think the "event" on the bottom line is a passing animal.  It shows up 
on the geophone trace underneath and it doesn't show at 
http://www.guralp.net/aboutus/realtime .  My sensors are in a double 
skinned wooden box, surrounding the concrete pad, about a meter cubed, 
with insulation in the 3" cavity all round, a "Kingspan" solid foam 
insulation slab on top, then a tarp cover and a wooden lid on top of 
that.   Everything is warm and dry inside

The weather where I am has been average for this time of year.  We have 
been close to the centre of the depression most of the day.  Some light 
rain and winds of about 30 mph.  The unusual thing is the record low 
atmospheric pressure.  Chris, though, is probably right, the simplest 
explanation is usually the correct one...

Cheers

Ian

jonfr@......... wrote:
> Hi Ian.
>
> You actually should record the ocean waves on your lechman in this type of
> storm. I don't how you protect your lechman outside, but in this type of
> storm not much is needed to break an weak setup. There is a earthquake
> recorded near the zero line at the bottom of the image. After that I see
> some weather noise as expected until it goes flat. So I must assume that
> something has happened to it. Maybe it got flooded by water or the cable
> got damged. It is hard to tell, you are going to have to look at it when
> the storm dies down.
>
> Regards.
> Jón Frímann.
>
>   
>> Hi,
>>
>> we have a record breaking low pressure system over us in Scotland just
>> now, 952 mbar or about 28".  My Lehman seems to have gone into limit,
>> given the flat line signal coming from it (see http://www.iasmith.com).
>> I wonder if the low pressure has caused the ground to tilt, ever so
>> slightly.
>>
>> I also wonder if it will come out of limit when the pressure goes up
>> again, though hysteresis will probably prevent it.
>>
>> Cheers
>>
>> Ian
>> __________________________________________________________
>>
>> 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)
>
> 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)


[ Top ] [ Back ] [ Home Page ]