Soil Liquefaction by Hurricane Katrina, Reply.

Dave, KI5NG, in response to N5RTF's proposal:

Having grown up experiencing hurricanes on the Texas coast (Deborah [cat. 1], Carla [cat. 4], Beulah [cat. 3]. and Alicia [cat.3]; I don't count Rita, during which we only had tropical storm-force winds) and having been in the eyes of the first three, I remember something that I rarely hear mentioned in this day of live reporting.

As the eyes of Carla and Beulah approached, there was a "buzzing" sound, very loud, that most resembled the sound made by a four-piston-engined bomber flying overhead. I remember WWII-era adults saying things like, "What idiots would be flying around in weather like this?" My dad, who had first heard this during a cat. 4 1949 hurricane (they weren't named back then), recalled that this sound seemed to occur when winds exceeded 125 mph or so.

Every dentist knows that freshly mixed dental stone (modified plaster-of-Paris) is virtually thixotropic before it sets. To get it to flow into the intricacies of our intra-oral impressions, we subject it to a vibrator that causes the stone to liquefy. During dental school, when there might be several of these things going at the same time, the sound was very similar to that of a piston-powered multi-engined plane or .... like the sound I heard during the peaks of Carla and Beulah.

I have always assumed that such liquefaction of dental stone followed the same physics as soil liquefaction during an earthquake. The interaction of strong airborne vibrations with the ground and water would certainly be highly complex, but why couldn't such vibrations, under the right conditions, produce standing waves of highly significant energies?

I think your deduction is brilliant. If I were a graduate student, I would be wetting my pants to get approval to do a thesis on this.

David - KI5NG