Re: sonar effects in whale strandings

"Jack Linthicum" <jacklinthicum@xxxxxxxxxxxxx> wrote in message
news:1130607613.712335.169030@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> Repeat of a paragraph above, 140 decibels at reception 300 mile from
> the source. 140 decibels is a jet aircraft, chainsaw, rock concert.
>
> "Since 1994, when NRDC began investigating rumors that sound
> experiments were taking place off the California coast, LFA
> (Low-frequency Active) sonar has been of particular concern because of
> the enormous distances traveled by its intense blasts of sound. During
> testing off the California coast, noise from a single LFA system was
> detected across the breadth of the North Pacific. By the Navy's own
> estimates, even 300 miles from the source these sonic waves can retain
> an intensity of 140 decibels -- still a hundred times more intense than
> the noise aversion threshold for gray whales. Many scientists believe
> that blanketing the oceans with such deafening sound could harm entire
> populations of whales, dolphins and fish."
>
Jack, do you know what the SL is of a humpback's whale song?
Take a guess....I'll tell you it's nearly 160 dB, so you want to argue
that 140 dB low freq signal is gonna harm it? How loud is 160 dB?

Also, over 52 human divers were exposed to LFA tranmissions of 157 dB
and none showed physiological effects.

I know, I'm using scienitific research here, and you're not. I'm also using
my eyes, I was on Cory Chouest during SRP phase III.

The research does not support the "theory" that 140 dB is too loud.

Two good links regarding the research:

http://www.surtass-lfa-eis.com/Download/index.htm

http://www.surtass-lfa-eis.com/Research/index.htm

Mark


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