posted on Apr, 5 2012 @ 08:46 PM
reply to post by Xterrain
I live not too far from Clintonville , but lived for over a decade in central California. I can tell you for a fact that unless that 1.5 was less than
forty feet under your feet you would never notice it , let alone hear it.
Interestingly you are exactly right:this particular section of Wisconsin has been relatively stable for almost 3.5 billion years. and the ground
composition is very very large chunks of granite and bedrock covered by at least a couple of centuries of 'not yet weathered away silt and dust'( a
perennial process that will ALWAYS have a relative "silt" coating depth in direct relation to yearly weathering and heaving).
This sets up an interesting condition: if it is a 'quake' down to a few hundred meters, even if small, the rocks in the sub soil will ring like a bell
and that ringing SHOULD become longer wave propagation when it transits the rock hard substances underground into the less dense soils near the
surface. just like the propagation of quake waves in the central valley in Cali ( but on a smaller propagation scale due to the relative depth and
composition of materials)
if it was a slightly deeper quake the area of noticeable effect should be over a much larger surface area ( ominous indeed , but luckily not the case
So...the most likely culprit is stress fractures occurring in "near" surface dense rock being bent or stressed to the cracking point.such a thing
would produce localized near surface noise as the near speed of sound cracking was translated into 'slow time' by the soft , low density surface
transition , resulting in a local boom , and vibration without much propagation .
THE very viscous fluid "shape" the sub surface rock floats on may have changed it's "level' state, from change in the earth's curvature ( possible
planet expansion ) or temperature state( higher average than before in history ), which would lower it's density slightly and allow the subsurface
granite to sink and flatten a bit ) .Or the the buoyancy of the near surface granite sub surface no longer is in the same 'buoyancy condition' as it
has existed in for epochs.
in any event if a chunk of subsurface granite was suddenly cracked on e would expect the exact conditions that we see in this environment.
if somone has already posted something like this throw a couple of tomatoes at my noobs and move on ( I am still on page one ) ;-)
edit on 5-4-2012 by Silverlok because:
edit on 5-4-2012 by Silverlok because: bm of the mind