Underwater sound transmission

["Griff Peters" <griff@griffpeters.com>]

Whales have the ability to communicate over extremely long distances,
perhaps hundreds of miles, underwater via low frequencies. Ocean floor
topography, thermoclines, and currents facilitate communication much
farther that previously thought. However, due to the industrial age and
mechanized shipping, there is now so much low frequency noise throughout
the world's oceans that a large portion of whales' long distance
communication has been eliminated forever.

Griff Peters
www.griffpeters.com


-----Original Message-----
From: mark sottilaro [mailto:marksottilaro@sbcglobal.net] 
Sent: Wednesday, March 16, 2005 10:35 AM
To: Loopers-Delight@loopers-delight.com
Subject: Re: Underwater latency (not completely OT) ;-)

Whales use a high pitch because, while not "going the
distance," they can get a higher resolution of SONAR
than they could if they use a lower freq sound with a
long wavelength.

--- Per Boysen <per@boysen.se> wrote:
> >> ...Since lower frequencies typically
> contain/require more energy in 
> >> the first place, they have a tendency to stay
> more coherent over a 
> >> longer distance.  That's one reason why the Navy
> can use ELF 
> >> (extremely long frequency) waves to communicate
> with submarines over 
> >> distances of many, many miles.
> 
> On Mar 16, 2005, at 4:43, Matthias Grob wrote:
> > and why create those huge whales such a high pitch
> sound to call?
> 
> Yeah, that's an interesting question that has been
> in my mind since I 
> was a kid and heard dolphins for the first time.
> Maybe they use this 
> for "short distance calls"? When I was scuba diving
> in the Red Sea a 
> "fish expert" told me that sharks (as most fish BTW)
> can "hear" with 
> their body. Along the left and right side lines they
> have receptors 
> that can measure water waves (known to us as
> "sound"). Especially 
> sharks are very talented in hearing those low
> frequencies that are 
> created by a fish fighting or splashing by the water
> surface (don't 
> swim like a damaged fish, if you don't want to call
> for sharks;-)
> 
> Maybe all fishes "hear" also much lower frequencies
> (like 1 - 2 Hz?) 
> with their body lines. I guess the sea should be a
> pretty noisy place 
> for a fish, if that's true, so maybe some sea
> animals keep their 
> communication in that higher pitch only to stay free
> from that terrible 
> noise floor?
> 
> Greetings from Sweden
> 
> Per Boysen
> ---
> http://www.looproom.com (international)
> http://www.boysen.se (Swedish site)
> http://www.cdbaby.com/perboysen
> 
> 
>