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They're probably fine... right? (lemmy.world)
submitted 4 months ago by [email protected] to c/[email protected]
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[-] [email protected] 78 points 4 months ago* (last edited 4 months ago)

Can you please explain to me, a simple person with no knowledge in that sort of thing?

I'm assuming the sonar emits a loud "ping" sound and the divers would probably deafened by it?

Edit: Holy shit ......

Thanks for all the great replies.

But holy shit ...

[-] [email protected] 139 points 4 months ago* (last edited 4 months ago)

Military sonars are so loud that if you happened to be idly floating near one (let's say closer than 500 meters away) as it does one of its strongest pings, your entire body would cavitate into pink mist; it's weakest ping would rupture every organ in your body instantly, all of your bones would fracture in place and some of your blood at the skin surface would boil from the sonars ping causing rapid pressure changes right in front of whatever is supposed to remain of your face.

Imagine standing next to a hundred grenades as they all simultaneously explode, but also pretend you are spared from the heat wave of the explosion and not the blast wave.

[-] [email protected] 123 points 4 months ago* (last edited 4 months ago)

Wait a minute

Have we been pulping marine wildlife this whole time? I just connected the dots there

[-] [email protected] 114 points 4 months ago

Yep. Its fucked. Literally drives whales to beach themselves.

https://en.m.wikipedia.org/wiki/Marine_mammals_and_sonar

[-] [email protected] 88 points 4 months ago

Like 10,000 dolphins were killed in the black sea in 2022 because of sonar.

[-] [email protected] 14 points 4 months ago

That's fucked. Hopefully aliens do the same thing to Earth soon.๐Ÿ‘ฝ

[-] [email protected] 55 points 4 months ago

Hey, man. Why do you hate dolphins so much that you want aliens to kill another 10,000?

[-] [email protected] 7 points 4 months ago

Ah the ol' switchroo

[-] [email protected] 2 points 4 months ago

The ol Lemmyaroo.

[-] [email protected] 3 points 4 months ago

Aw, we don't have a Lemmy switchroo link tree yet.

[-] [email protected] 50 points 4 months ago

There's two types of military SONAR: active and passive. Active SONAR is using pings and listening for the echo, but it's not very commonly used by submarines. Passive sonar is just listening out for engine noise from ships and prop noise from other submarines. Warships use active SONAR more because they're already noisy and so if they think an enemy submarine is in the area they'll use it to try and locate, but in peacetime it's mostly reserved for training exercises. It's still terrible for wildlife, even if they don't die it's very distressing and disorientating but it's not constantly scanning like a RADAR.

[-] [email protected] 49 points 4 months ago* (last edited 4 months ago)

Sonar systems[...]generate slow-rolling sound waves topping out at around 235 decibels[...]. These sound waves can travel for hundreds of miles under water, and can retain an intensity of 140 decibels as far as 300 miles from their source.

140 dB is a gunshot at the source. About 190 in air pressure will cause an explosive shockwave that can kill a person. 235 dB in dense water pressure is...somewhat more violent, as we understand how the decibal curve works and molecular pressure at depth.

[-] [email protected] 38 points 4 months ago* (last edited 4 months ago)

But that means that a person would be killed even if they are miles away? Maybe tens of miles.

Found it: Based on sonar guidelines and studies on sound propagation, a diver exposed to 235 dB low-frequency sonar would likely need to be more than 1.5โ€“2 kilometers (1โ€“1.2 miles) away to ensure safety.

However, pings are conical and the strongest sonar is at the bow. So you could literally be safe if you were diving behind it.

[-] [email protected] 20 points 4 months ago

This R*ddit comment suggests that it's only close-range that it's reliably lethal.

[-] [email protected] 2 points 4 months ago

Every 10dB is twice as much energy, so 235 dB is pretty scary.

[-] [email protected] 5 points 4 months ago

I think people are missing that this is extreme exaggeration.

[-] [email protected] 4 points 4 months ago

Not exactly, navy sonar has history of kills, but I haven't heard of something shattering into pink mess by that. Though military stuffs aren't always public.

[-] [email protected] 4 points 4 months ago

It was fun to read though. But I believed it until I checked.

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this post was submitted on 08 Jan 2025
242 points (99.2% liked)

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