One theory about the Mediterranean Sea is that several times, up until five   
   and a half million years ago, the Sea periodically would be cut off from the   
   Atlantic (or other parts of the world ocean) and dry up.  This is plausible   
   because the Mediterranean    
   is an evaporative sea, the rate of evaporation exceeds the influx of water   
   from the tributary rivers and rainwater.  Even today, if something cut off the   
   connections through Gibraltar and Marmara, the Mediterranean would begin to   
   dry up.   
      
   The theory of the Zanclean Flood is that during that last such period of   
   desiccation, something broke the barrier at what is now Gibraltar, and the   
   Atlantic came flooding in to a basin that was either mostly dry, or host only   
   to shallow seas kilometers    
   below world sea level.   
      
   The 'fast fill' model would have it that the mostly-empty Med basin filled up   
   to about its current state quickly, possibly in as little as a few months to a   
   few years.  There is also a slow-fill theory that holds that a much smaller   
   flow took thousands    
   of years to refill the basin, which would be far less dramatic.   
      
   Assuming the fast flow model is right, though, the influx through what would   
   become the Sraits of Gibraltar would have been gargantuan.  The figures   
   suggest 1000 Amazon Rivers, pouring through at a tremendous rate.   
      
   Assuming that's true, assuming a human was somewhere in the region, how far   
   away would he be able to hear it?  How far would he be able to feel the   
   vibrations in the ground?     
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)