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Ship spies largest underwater eruption ever (sciencemag.org)
112 points by Fifth_Star on May 24, 2019 | hide | past | favorite | 35 comments



It's interesting to read an article and come to HN hoping to find more interesting comments only to find one thread with stupid memes.

Is this the largest ever because we're just starting to be able to map this type of stuff or have we seen a lot of them and this is enormous?


Well there is this, "The map of the sea floor, made by the ship’s multibeam sonar, indicates that as much as 5 cubic kilometers of magma erupted onto the sea floor."

I think 5 km^3 is a large eruption by any standards. Looking at lists of modern ones it's a index 6 event which happen every few decades on land. From the article it sounds like if it weren't close to Mayotte it wouldn't have been picked up seismically.


... gas trapped inside the black volcanic material.

Sudden release of such gases has been suspected in the case of a number of sudden ship disappearances over the centuries. If a bubble's volume is large relative to the ship's, the ship will drop to the bottom as the gas forces water from under the hull. Then the surrounding seas crash onto the decks.


Try to picture this. All the water next to a ship mysteriously flowing away from the ship, over the bubble while the ship for some reason is the only thing going down through it.

Water is also heavier than air, and water on top of a bubble will also fall into the center of the bubble (breaking it up into smaller bubbles), until the surface tension of the water around the bubble is great enough to hold it together (small bubble).

Therefore a huge bubble gets split into many bubbles, I suppose at depth a lot of the gas gets dissolved into the water. The worst that would happen is many small bubbles cause the density of the water to decrease, causing the boat to sink lower into the water. I'm not sure if the water could lose enough density to sink a regular boat directly?

I think what you may be thinking of is large, shallow explosions (generally man made) under a ship which create a temporary bubble which then collapses in on itself, but can cause extreme stress on large ships.

Extremely contrived example of bubbles being able to sink a small boat: https://www.youtube.com/watch?v=MSmAXp_BHcQ

How a bubble generated by an explosion can actually sink a large ship: https://youtu.be/UdFNuc5XtII?t=192


There is a no-sail zone quite near the coast of Grenada due to an active underwater volcano. The volcano is called Kick 'em Jenny and has sunk numerous boats over the years. On one instance it sunk a boat and killed 60 people.


Wikipedia link for the lazy https://en.wikipedia.org/wiki/Kick_%27em_Jenny#Maritime_excl... The part about the "sinking hazard" has a [citation needed] anyway. The Spanish version look more concerned about eruptions than bubbles, and says that when they detect unusual activity the radius is increased from 1 mile to 3 miles.


Well that about wraps up the Bermuda Triangle for me


Bubbles that large are not stable—the sinking effect (which is disputed) would have to do with a significant reduction in density of the water by a large number of smaller bubbles.


is this too deep for a tsunami effect? can underwater volcanoes cause tsunamis?


The article says it’s too deep to cause a tsunami, at least where the quakes are now. If seismic activity starts moving towards land and a big quake is close enough, a shelf-collapse could cause one.


That would be scary, seeing as I believe the largest tsunami ever was created via a similar mechanism.

Edit: not the largest, but large. See: https://en.m.wikipedia.org/wiki/Storegga_Slide


[flagged]


Could you please not start shitty subthreads by posting flamebait to this site?

https://news.ycombinator.com/newsguidelines.html


Sorry, you're right this was useless. My bad.


Thanks—appreciated.


The onus is on the person making the claim to bring evidence to the discussion.

"What can be asserted without evidence can be dismissd without evidence" -- C. Hitchens

Since the comment was removed or deleted it originally said something like "Underwater volcanoes are the cause of Climate Change -- prove me wrong"


Since the question has been asked, I found this to be relatively convincing to the casual observer:

https://www.bloomberg.com/graphics/2015-whats-warming-the-wo...


Perhaps the only thing more absurd that original is censoring it and removing it.


It's not removed. Turn "showdead" on in your profile.


Low quality comments are removed when flagged by enough people. It's actually a good thing.


[flagged]


I find that the Venn diagram of

<dissent>

vs <evidence-free assertions, disruption, distraction, and disingenuous arguments>

do not overlap, and it is useful to distinguish between the two and to treat them differently.

To paraphrase Asimov, one person's ignorance (deliberate or not) is not equal to another's knowledge.


There are many factors in climate change. Some more impactful than others


You, and opinions stated as facts by ignorant people are exactly what is wrong with the internet. I used to think everyone having a voice was a wonderful, liberating new freedom for the whole world. The last few years have really changed my mind.


That's really depressing that you think that way. That way of thinking is pretty dangerous. I know it's a "slippery slope", but thinking that certain people shouldn't express their opinions on things in a public place goes against everything the internet gave us so many years ago.


Everyone has a right to their own opinion, no one has a right to their own facts though. I get what you're saying but there are consequences to certain types of misinformation (ex.: anti-vaxxers). It's a complicated issue.


I think we're in a state of transition that will take a few decades to resolve itself.

In the past, it was difficult to get an idea published. Money and power are definitely not sufficient to show that someone's ideas should be listened to (in some cases, the converse is true), but they're at least weakly correlated to competence. Also, when the barrier to entry was higher, less was produced, so there was a lot more opportunity for coversight.

This lead to printed words and popular speech having an air of authority and truthfulness. I expect that this will be swiftly eroded, and replaced with more caution, as society adjusts.


If you take away the right for anti-vaxxers (or climate change deniers in the OP's case) to talk about things on a public platform where they're actively ridiculed, they're going to go underground and create their own communities under the radar.

Say someone goes to that community to try and convince them otherwise and says "hang on, vaccines don't cause autism, here's some research articles", they'll get banned and their post removed, and everyone in the separate community is none the wiser and nobody who uses that community will ever have the chance to be convinced otherwise.

So if you really wanted to stamp out the anti-vaxxers, I guess you'd have to have some kind of monitoring to make sure they don't post anything anywhere about anti-vaxx views. That would need to be done by someone or something powerful, say... Facebook or the government? I don't trust Facebook as their ulterior motive is selling your data for sweet sweet ad money, and I don't trust the government as many governments have shown in the past many times they can't be trusted to regulate speech of citizens (not that I would EVER want to regular speech)

So - why not just let them speak on large public platforms and have them get laughed at?


I never said anything about people making laws about anything. And they do get laughed at, but then they claim that they're somehow being censored by all the negative responses they get. And none of it makes a difference. For a lot of people, universal condemnation on Facebook or Reddit or whatever is just further proof that they're on to something.

All I'm saying is that there's disinformation, and then there's harmful disinformation, and on top of that there's a recent trend amongst certain podcast listeners in a certain demographic to insist that allowing people to spread harmful disinformation as far and wide as they want to will magically reveal how fake and harmful it is to everyone. I don't know what the answers are, I just know the binary answers are wrong:

(0) The government should pass laws prohibiting free speech about stuff the government has determined is "wrong".

vs.

(1) If only everybody could just say whatever they want anywhere and anytime they want without repercussions, social pressures from Internet forums will make them realize how wrong they are! Because if there's one thing we've learned about Internet forums over the past 30 years, it's that they bring everyone together and magically help filter out truth from falsehood? Or something.

I don't have any answers, I just know that neither extreme is helpful, and I'm extremely not sympathetic to the likes of anti-vaxxers and conspiracy theorists.


> they're going to go underground and create their own communities under the radar

I dunno, they're already doing that anyway. And OP clearly has no interest in actually sticking around and debating this point, just in trolling us, so it's not like flagging their post shuts down conversation in any meaningful way.


Great, let them go to their own communities. Time was fringe beliefs stayed mainly in the shadows. If you wanted to believe in a flat earth, or deny climate change there was probably some guy running an amateur newsletter you could subscribe to, maybe small scale meetings to attend. Those subscribing to a more mainstream view need never know or care.

Why should every reasonable conversation about climate, vaccination, and others give space to allow constant sealioning? It spoils every discussion and ruins it for those trying to discuss and learn in good faith - whilst entertainment for the troll lobbing the one sentence hand grenades.

> "If you take away the right for anti-vaxxers to talk about things on a public platform" vs "someone goes to that community ... they'll get banned and their post removed"

So you're actually advocating for the paradox of tolerance? They can moderate the discussion in their under the radar community to stay on topic, but the world in general should not and should just take the consequences and pollution?


cakeface claimed to be stating fact, not opinion. cakeface supplied no evidence, and instead attempted to reverse the burden of proof. And the claimed fact is rather farcical on its face; it certainly needs some evidence in order to be believed.

No, I don't think much would be lost from the discussion if that comment were removed. We'd lose some noise, but very little signal.

I agree that there is a slippery slope. I don't know where to draw the line. But HN gives us a way to downvote and flag comments like this one for a reason - they add negative value, and the discussion is better off without them.


Why the correlation with CO2 levels then?


[flagged]


Not responsible, but "contributing to". It's a natural process of the earth, but I don't deny we're rapidly accelerating it out of control.


The sun and natural variables in the incredibly complex climate system are FAR larger factors.

Prove me wrong.


Your claim is that before humans, Earth's climate was static?


I read that headline as "Ship spies largest underwear eruption ever"

I can't even say where my mind went, 'cause it hasn't come back yet...

Fridays are hard. Especially on mobile screens.




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