In My Layman Opinion you will have to detect tornadoes by looking only at
local area of the tornado itself and possibly indirectly by looking at
the derbies bouncing on the ground like autos or trees being ripped from 
the ground
These frequencies might be higher into the audio spectrum
and thus will be attenuated more quickly and thus limited to
the immediate vicinity of the tornado requiring an array too expensive
to maintain. What the weather people currently do to forecast
tornadoes are the best way to go like watching for
crossing currents of air in the sky.
Tornadoes are very small focal points of energy where forces are
somewhat balanced against each other like
centripetal force VS in-rushing air.
Small usually means higher frequencies.
Best to watch for intensive moving air pressure changes
in the air and possibly the ground noises also.
A combination of key factors and not any one thing.
Just a thought, from a layman.
A layman named geoff.
:-)




On 4/7/2013 3:05 PM, Thomas Dick wrote:
> Since things are quiet on the network lately and even Geoff has 
> commented on this subject in the past, I'd like to return to this 
> issue......on Steve Jones' Facebook page, 
> http://alabamaquake.com/reports.html#Tornado_Seismic_Signature a 
> couple of paragraphs on the above issue surfaced lately. (_Tornado 
> Detection Based on __
> __Seismic Signal," Tatom/Knupp/Vitton; 18 July 1994_) I replied to his 
> post with this:
>
>
> I got strongly criticized by the Paducah regional weather people and
> pulled back after the initial discussion on PSN network. But, I have
> spent many hours studying weather and what I see on the seismic
> equipment.  I learned to recognize the signatures of strong storms off
> the coast of Alaska, Great Lakes, east coast and off the SE coast of
> Greenland....even hurricanes in the Gulf. This is what I know. The Ohio
> group that suggested a peak around .15 to .25 Hz were seeing Great Lakes
> waves/wind....not a tornado. I have learned  what to expect on the N-S
> or E-W Lehman.
>
> Frank Tatom called the US array system to my attention. I examined the
> Harrisburg, ILL tornado data and felt it was too short of a path. I also
> did extensive study on the Henryville, IN  tornado which actually went
> over into Kentucky. I felt that the hilly terrain confuses the issue....
> it is still too early, we are still doing preliminary
> study/investigation work.  I also used the USArray to look at the
> Oakland City, IN macroburst.
>
> I honestly can't say I can put my finger on a specific frequency that
> fits all these situations. IU claimed they saw something in the
> Harrisburg data (which I believe), but it was more likely the collapse
> of the storm cell .... something like I saw on the Oakland City, IN
> macroburst.
>
> Tatom and Vitton were looking for a specific frequency; something that a
> detector could easily recognize. I really believe it exists. Personally
> I suspect it to be higher than .2 Hz. I spent time interviewing people
> who experienced the tornado I brought to the PSN network for discussion.
> I did the same in conjunction with the Branson, MO tornado as well as
> Joplin, MO. If those who experienced these tornadoes say anything about
> hearing the tornado, they all agree it sounded somewhat like a train.
> Wind by itself creates sound too....ever hear the upstairs wind howl?
> Even earthquakes can emit "sound", don't you agree? Logically, this common
> thread of "sound" must be a clue to either higher or lower creator of
> the "sound" exists BUT NOT this .2 Hz. What we hear may even be
> harmonics of the original frequency.
> This last two sentences have haunted me all night. Sound is a common 
> denominator. Have I missed something? Where do we look?


-- 
*************
It is by the Entropy, That I set my mind in Motion.
Entropy is the seeking of equilibrium.
It is by the Entropy that, I set my mind in motion.


  
    
  
  
    
In My Layman Opinion you will have to
      detect tornadoes by looking only at

      local area of the tornado itself and possibly indirectly by
      looking at

      the derbies bouncing on the ground like autos or trees being
      ripped from the ground

      These frequencies might be higher into the audio spectrum

      and thus will be attenuated more quickly and thus limited to

      the immediate vicinity of the tornado requiring an array too
      expensive

      to maintain. What the weather people currently do to forecast

      tornadoes are the best way to go like watching for

      crossing currents of air in the sky.

      Tornadoes are very small focal points of energy where forces are

      somewhat balanced against each other like

      centripetal force VS in-rushing air.

      Small usually means higher frequencies.

      Best to watch for intensive moving air pressure changes

      in the air and possibly the ground noises also.

      A combination of key factors and not any one thing.

      Just a thought, from a layman.

      A layman named geoff.

      :-)

      

      

      

      

      On 4/7/2013 3:05 PM, Thomas Dick wrote:

    
    

      
      Since things are quiet on the network lately and even Geoff has
      commented on this subject in the past, I'd like to return to this
      issue......on Steve Jones' Facebook page, http://alabamaquake.com/reports.html#Tornado_Seismic_Signature
      a couple of paragraphs on the above issue surfaced lately. (Tornado
          Detection Based on 

        Seismic Signal,” Tatom/Knupp/Vitton; 18 July 1994)  I
      replied to his post with this:

      

      

      
I got strongly criticized by the Paducah regional weather people and 
pulled back after the initial discussion on PSN network. But, I have 
spent many hours studying weather and what I see on the seismic 
equipment.  I learned to recognize the signatures of strong storms off 
the coast of Alaska, Great Lakes, east coast and off the SE coast of 
Greenland....even hurricanes in the Gulf. This is what I know. The Ohio 
group that suggested a peak around .15 to .25 Hz were seeing Great Lakes 
waves/wind....not a tornado. I have learned  what to expect on the N-S 
or E-W Lehman.

Frank Tatom called the US array system to my attention. I examined the 
Harrisburg, ILL tornado data and felt it was too short of a path. I also 
did extensive study on the Henryville, IN  tornado which actually went 
over into Kentucky. I felt that the hilly terrain confuses the issue.... 
it is still too early, we are still doing preliminary 
study/investigation work.  I also used the USArray to look at the 
Oakland City, IN macroburst.

I honestly can't say I can put my finger on a specific frequency that 
fits all these situations. IU claimed they saw something in the 
Harrisburg data (which I believe), but it was more likely the collapse 
of the storm cell .... something like I saw on the Oakland City, IN 
macroburst.

Tatom and Vitton were looking for a specific frequency; something that a 
detector could easily recognize. I really believe it exists. Personally 
I suspect it to be higher than .2 Hz. I spent time interviewing people 
who experienced the tornado I brought to the PSN network for discussion. 
I did the same in conjunction with the Branson, MO tornado as well as 
Joplin, MO. If those who experienced these tornadoes say anything about 
hearing the tornado, they all agree it sounded somewhat like a train. 
Wind by itself creates sound too....ever hear the upstairs wind howl?  
Even earthquakes can emit "sound", don't you agree? Logically, this common 
thread of "sound" must be a clue to either higher or lower creator of 
the "sound" exists BUT NOT this .2 Hz. What we hear may even be 
harmonics of the original frequency.
      This last two sentences have haunted me all night. Sound is a
      common denominator. Have I missed something? Where do we look?

    
    

    

    
-- 
*************
It is by the Entropy, That I set my mind in Motion.
Entropy is the seeking of equilibrium.
It is by the Entropy that, I set my mind in motion.