Re: Ice tweeks
> This should no be so much off-topic, because these crackling ice soundslook
> look exactly like the tweeks which can be received by night on ELF/VLF.
> Performing a spectral analysis shows that the ice acoustical sounds
> exactly like the electromagnetic tweeks.That´s not too surprising.. Dispersion is a pretty common
phenomenon in nature.
At a guess though, I would have said that the noise you
hear with stones on ice is a surface acoustic wave on
the ice surface (Surface acoustic waves are also strongly dispersive)
and little to do with the depth of the lake (but probably a function
of the diameter of the lake and the thickness of the ice)
I also remember the sounds from childhood from an iced over
paddling pool that was only a foot deep giving similar noise.
I suspect it is largely water depth invariant (perhaps
some bored person can carry out an experminent?)
Interstingly, liquid water is also dispersive.. if you throw a
pebble into a pond the shortest, fastest ripples will reach the bank
first followed by the lower frequencies. You have to be watching
pretty carefully though to appreciate it though. In this case,
depth of the pond does matter.
Cheers, Hugh Gibson