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CrustalTrudger t1_ja2vj0e wrote

A form of this question is asked after virtually every large earthquake that makes the news, so I'm going to keep my answer generic with the futile hope that I can put this in our FAQs and maybe retire this question. To first cover the underlying geology and earthquake behavior, there are specific processes by which one earthquake can trigger others. This is discussed in more detail in one of our FAQs, but in short we can consider either static or dynamic triggering. Static triggering is where the permanent movement of the crust that results from a particular earthquake changes the stress state on neighboring faults pushing some of them closer (or past) failure through stress transfer. Static triggering occurs over a very limited distance (roughly X km away from anywhere along the portion of the fault that ruptures where X is the total length of the original rupture). Dynamic triggering is where passing seismic waves, and the temporary change in stress they induce, causes a portion of a fault to fail. Dynamic triggering can occur over long (i.e., teleseismic) distances, but it tends to mostly be associated with very large magnitude earthquakes as the generative event, is pretty rare, is temporally limited (i.e., we only consider dynamic triggering to be possible over a narrow time window after the original event), and is hard to demonstrate. Given the above, when this question gets asked, i.e., "There was a big earthquake in location X and then there were moderate magnitude earthquakes in distant locations in the days, weeks, or months following, are they related?" there is a vanishingly small probability that one or more of those events may be a dynamically triggered event, but the overwhelmingly vast majority of the time, the answer is firmly and unequivocally, "No, they are not related".

So what's going on and why is this question asked so often? Mostly cognitive biases. Specifically, some mixture of the frequency illusion and the clustering illusion. The frequency illusion (or Baader–Meinhof phenomenon) is basically the tendency for your brain to take note of similar events after you become aware of an event. So, a large magnitude earthquake hits a populated area and makes the news and for some period after that you (and the news media more broadly) take note of other even moderate magnitude events. This also brings in the second bias, i.e., the clustering illusion, or the tendency for us to see patterns in stochastic (random) things. Within this context, it's worth considering just how many earthquakes of a given magnitude there are, e.g., the global statistics from the USGS. You'll notice a rough logarithmic behavior in these, i.e., for M8+ we expect about 1 a year, for M7-7.9 ~15/year, for M6-6.9 ~150/year, for M5-5.9 ~1500/year, and so on. So in a scenario where one of the ~15 7-7.9 events happens in a populated place and you notice a tiny fraction of the hundreds to thousands of 6-6.9 or 5-5.9 magnitude events we expect every year that also occur in a different populated place (i.e., excluding aftershocks from the original event) in the following days/weeks, does that mean anything or imply any linkage? No, almost always, it represents nothing other than you paying attention to a small fraction of events because you are primed to and seeing patterns that aren't there.

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andrewmmm t1_ja3cho5 wrote

A good example of the Baader–Meinhof phenomenon that most people encounter in their lives is with new words. Have you ever seen a word you’ve never seen before, looked up the definition, then all of the sudden you see the word everywhere? That word has always presented itself to you, but you have only taken notice now that you learned it. This is the same effect.

For example, I had never seen the word “ephemeral” until I was reading a tutorial the other day and had to look up the definition. I swear I have seen that damn word like 4 times this week in completely unrelated scenarios.

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PMMEANUMBER1-10 t1_ja4td4b wrote

The irony is that after learning about Baader-Meinhof, you'll start to see it everywhere too

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Shrimpits t1_ja5sc7z wrote

It’s funny because I just learned about the Baader-Meinhof phenomenon a couple weeks ago

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Fritzkreig t1_ja6d5o0 wrote

I used the Baader-Meinhof phenomenon in a online discussion thread in my masters language aquisition course work.

The PhD. teaching the course called me out about how in the world does an 80s communist German terror organisation have anything to do with out discussion.

I sent her some links, and let her know she will being seeing those words in her life more frequently now.

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Veestoria t1_ja705bz wrote

Hmmm this is the first I hear of it EVER so I’ll come back and let y’all know if I come across it again sometime soon!

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Shrimpits t1_ja7fv8e wrote

Please do! I have had the actual phenomenon happen to me a lot (first time I ever remember was when I learned what “serendipitous” was and then the next day I heard it used in the movie Let’s Go To Prison lol), but I never knew what it was called until I googled it recently, and now the name popped up in the wild

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[deleted] t1_ja3gmgb wrote

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[deleted] t1_ja3ibk7 wrote

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NotTooDeep t1_ja4il4p wrote

> Baader–Meinhof

I've been googling on something that should be related to this for a while and can't find the info. My question is this: what is the opposite of the Baader–Meinhof phenomenon?

I recall watching a show decades ago that described the discovery of nerve cells in the lymph nodes in the 1970s or 80s. The research overthrew the common understanding that the immune system was autonomous from the rest of us, especially our brains, and kind of just did its thing. This gave some credence to depression as having a role in reducing our immunity to disease. You catch more colds when you're down.

The person interviewing the scientist asked why it had taken centuries for anyone to see these nerves. All of the thousands of med students and researchers and physicians did not see these nerves.

Is there a word or phrase that describes this phenomena? Blind spot comes to mind, but not the physical blind spot in the eye; I'm referring to some kind of blind spot that filters out images in the brain because we 'know' they don't exist, so we don't see them.

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notionovus t1_ja4vwx5 wrote

The term you might be referring to is scotoma. The technical term for a "blind spot" in the eye, it is used in psychology to refer to something you become blind or ignorant of.

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4x49ers t1_ja55m7i wrote

I'm thinking of something I learned as task oriented blindness but is apparently really called Inattentional blindness.

>Inattentional blindness or perceptual blindness (rarely called inattentive blindness) occurs when an individual fails to perceive an unexpected stimulus in plain sight, purely as a result of a lack of attention rather than any vision defects or deficits.

To over simplify a bit, they didn't see them because they weren't looking for them. You might have heard of the invisible gorilla test which demonstrates it, and I recall a BBC program where they were testing it as well: they had a pilot fly some people from A to B telling them to keep an eye out for X, I can't recall. Anywhere they flew over Stonehenge on the way there, and no one saw it, then flying the same route back (without being told to look for X) they were surprised to find it along the same path.

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NotTooDeep t1_ja57gpp wrote

Yes. I found that Wikipedia page as well. This also makes me think about situational awareness. That scene in the diner in the original Bourne Identity movie, where he can't recall who he is, but tells the young woman who is helping him about the people and objects in the environment around him and what their meaning is.

I imagine a professional boxer sees arm and foot movements in a different way than someone who has never seen a boxing match.

Your example of the flight over Stonehenge is funny! Thanks for that.

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g0d15anath315t t1_ja62024 wrote

Sounds sort of like the "phenomenon" of Psychic Blindness.

The brain doesn't comprehend what it's seeingsl so it just subs in something that does make sense.

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mouldybun t1_ja72awh wrote

I noticed ephemeral in a book I read last year, funny you should choose that word... because I do feel I see it around more, but it must be purely the way I'm reacting to it, because in the book it's used to refer to non immortal, non digitized humans (the book is we are legion we are bob.) and it's sort of elevated the word to a new status... but I've been using google Vm's for years prior... and when you dont have a static IP its "ephemeral". Its odd how it's been this background thing and I literally never paid it any mind

Also, I think I did look up the definition... or the definition was explained in the book.

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LibertyLizard t1_ja3vrhd wrote

Another reason is that the media plays to this bias—they know people will be more curious about other earthquakes after a huge disastrous one, so they will publish stories on earthquakes that would not have made the news otherwise to capitalize on that interest. This can give the illusion that more earthquakes are happening because how else would you hear about the ones on the other side of the world?

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8myself t1_ja5jlbh wrote

damn you must be smart, just reading your explanation i felt like my iq went up by 1.

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Welpe t1_ja6lj14 wrote

Fortunately/Unfortunately, IQ doesn’t work like that, gaining knowledge shouldn’t increase IQ theoretically or IQ fails to measure intelligence. Knowledge isn’t intelligence. I of course say “shouldn’t” because IQ tests are already flawed and this is veering off-topic but I really wish we wouldn’t conflate IQ score and knowledge or educational attainment (Or even intelligence for that matter, but that’s a whole ‘nother rant).

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foureyesequals0 t1_ja6npwg wrote

But are IQ test scores related to the earthquakes?

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Welpe t1_ja6rbj9 wrote

“If you torture data long enough, it will confess to anything” - Ronald Coase

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_AlreadyTaken_ t1_ja3lkt6 wrote

It would be just as unlikely for there to never be earthquakes close to each other in time.

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TealSwinglineStapler t1_ja6deek wrote

People will still ask the question after each major earthquake, but you've make sure I won't be one of them. So thanks!

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[deleted] t1_ja3dii6 wrote

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Vladimir_Putting t1_ja6z7im wrote

Wow, I had no idea there was an 8+ earthquake every year on average.

That alone really explains how we only take notice when it directly impacts a populated area. I'm sure most people think those are truly once in a lifetime seismic events. But really, they happen quite frequently, especially when you are talking in geological terms.

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MyPlantsEatPeople t1_ja6r2el wrote

Does this also apply to all the toxic chemical spills and train derailments the last couple weeks?

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Fizyx t1_ja76z87 wrote

Actually, yes. In the last 30 years, the US has averaged about 1,700 train derailments annually. Over the last decade, hazardous material releases as a result of derailment has averaged about 17 annually. That's about 1 every 3 weeks.

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kynthrus t1_ja6qe1s wrote

The relation is that they are all on Earth. Tectonic plates moving causes pressure to build somewhere else and when that snaps (quake) pressure builds somewhere else. Large quakes have aftershocks as well that last for years.

For Japan quakes above 5 or 6 are very common several times a year, their infrastructure is built for it though.

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CaruMel t1_ja90e8c wrote

If you are at all interested in how frequent earthquakes are around the world then you can use an app that actively notifies you of seismic events as they happen and shows past events. I have family in Japan and I use one to keep track of any new events there. Having been in a few earthquakes myself in Greece, Japan and Spain I kinda got hooked on tracking world events too.

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stateofyou t1_ja6b641 wrote

It’s been a long time since a big earthquake struck Japan, considering how frequently they hit. The biggest one was about 12 years ago and it was the tsunami that caused the most loss of life. As for the earthquake in Haiti, it’s a failed state with no building codes.

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