> In the Keyser Pod experiment, the cumulative sound exposure level (SELcum) value was 191.29 dB re 1 μPa2s at a distance of 10 meters from the transmitter. Note that this value is within the limits defined by Marine Mammal Protection Act (MMPA) for all marine mammals except for mammals that lie within high-frequency cetacean hearing group. However, there were no mammals from this group (or any other group) within the 10-meter radius of the
transmitter.
190 dB ???!? Is that different under water, and how much is left after 10m?
I mean 130-140 dB is the jet engine and the range were exposure without plugs is painful and longer than few seconds causes damage. This is 6 magnitudes higher, how can this be a good idea?
(Sounds like microwave wireless energy transmission: it's great, unless you care for birds which just get roasted if they fly through the beam?!).
And evidence of bison killings predate bison being nearly killed off. It's more about sonar causing more whales to beach themselves, not that it didn't happen ever in nature, but that our actions cause it to happen way too often. This is a weird argument.
the earth makes all sorts of horrible noises across the spectrum.
I think that it's unfair to use that as a defense of sonar unless you're certain that the number hasn't been trending upwards since the beginning of sonar usage.
if whale navigation is somehow affected by strange very high or very low noises it's not outside the realm of possibility that there have been plenty of whales beached simply due to tectonic/planetary movement inducing confusion.
I wonder if you could use free space optics or mm wave radio (above the absorption spectrum of water) to do this without the environmental externalities. Dispersion is still a problem underwater with these high frequency EM waves, but presumably a researcher could deploy some relays along with the cameras.
Passive sound absorption for power could also work without any sort of active sonar pinging.
thesausageking|3 years ago
> In the Keyser Pod experiment, the cumulative sound exposure level (SELcum) value was 191.29 dB re 1 μPa2s at a distance of 10 meters from the transmitter. Note that this value is within the limits defined by Marine Mammal Protection Act (MMPA) for all marine mammals except for mammals that lie within high-frequency cetacean hearing group. However, there were no mammals from this group (or any other group) within the 10-meter radius of the transmitter.
throw827474737|3 years ago
I mean 130-140 dB is the jet engine and the range were exposure without plugs is painful and longer than few seconds causes damage. This is 6 magnitudes higher, how can this be a good idea?
(Sounds like microwave wireless energy transmission: it's great, unless you care for birds which just get roasted if they fly through the beam?!).
matt_the_bass|3 years ago
Maursault|3 years ago
While I join the outrage, evidence of whale beachings predate the development of sonar by some 14K years.
iancmceachern|3 years ago
serf|3 years ago
I think that it's unfair to use that as a defense of sonar unless you're certain that the number hasn't been trending upwards since the beginning of sonar usage.
if whale navigation is somehow affected by strange very high or very low noises it's not outside the realm of possibility that there have been plenty of whales beached simply due to tectonic/planetary movement inducing confusion.
david38|3 years ago
pvaldes|3 years ago
pclmulqdq|3 years ago
Passive sound absorption for power could also work without any sort of active sonar pinging.
sva_|3 years ago
https://m.youtube.com/watch?v=sCmyZYYR7_s
pvaldes|3 years ago
But it looks damn sexy