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The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

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Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#21

Post by jobigoud »

cheriot wrote: post #13
abhinai wrote: post #5

Why haven’t I heard about this before? This seems too important a detail for my school textbooks to have left out and for popular culture to lack any references to it whatsoever. What am I missing?

> But nearly 60 years after the pulse was first observed, no one has managed to figure it out. That may be because, as far as seismologists are concerned, it’s just not really a priority. “There are certain things that we concentrate on in seismology,” explains Wiens. “We want to determine the structure beneath the continents, things like that. This is just a little bit outside what we would typically study … [since]…

Such a weird justification. If they don't know what's causing it how do they know it won't help explain the structure beneath the continent or the deep structure of the Earth.

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#22

Post by mucsun »

hugey010 wrote: post #16

Never heard of this, so I had to do some digging. My money is on this being an ocean wave phenomenon. The Gulf of Guinea, specifically the Bight of Bonny, is up to ~20,000ft deep. Average ocean waves have a period less than 15s and the average ocean depth of the Atlantic is ~11,000ft. Oddly similar ratios! So it's plausible this 26s wave period is caused by the increase in depth [0]. The abnormally large seismic ampl…

Never heard of this either, but I don't agree with your theory, as waves usually form only superficial on the ocean.

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#23

Post by jusssi »

aaron695 wrote: post #14
abhinai wrote: post #5

Why haven’t I heard about this before? This seems too important a detail for my school textbooks to have left out and for popular culture to lack any references to it whatsoever. What am I missing?

> Why haven’t I heard about this before? It's probably just part of the "Earth's hum", which is waves. (Don't confuse this with the world wide paranormal hum people claim to hear) You probably should have learned of the hum at school, if you did, you'd have probably forgotten. As a 10 year old you'd either find it amazing and think of it forever or just forget. It would be interesting to rank it on the importance lev…

> (Don't confuse this with the world wide paranormal hum people claim to hear)

Taking this sort of random swipe at at people who experience this is kind of rude. Even though it's pretty much confirmed it's not a real audio signal coming from outside of a person's body, there isn't quite enough evidence it isn't a real auditory sensation for these people (instead of psychological or "paranormal" issue).

I do get the hum sometimes, usually happens when my shoulders are tense. Also usually only in one ear, which is why I was able to pretty quickly rule out an external source (though when it first happened, I did spend some time opening and closing windows, listening at ventilation ducts, trying to locate it).

Edit: I'll add it here that sometimes it is a real sound. We live a couple of km away from a harbor, and the sound we get to our place from an idling cruise liner is very similar to what my ears sometimes generate by themselves. It's really hard to tell them apart except by trying if it gets louder (and more high freq components) by opening a window. The point is, at least in an urban environment it can be pretty hard to tell if the hum is real or not.

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#24

Post by richrichardsson »

abhinai wrote: post #5

Why haven’t I heard about this before? This seems too important a detail for my school textbooks to have left out and for popular culture to lack any references to it whatsoever. What am I missing?

You're missing more XKCD in your life!

https://xkcd.com/2344/

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#27

Post by pa7x1 »

hugey010 wrote: post #16

Never heard of this, so I had to do some digging. My money is on this being an ocean wave phenomenon. The Gulf of Guinea, specifically the Bight of Bonny, is up to ~20,000ft deep. Average ocean waves have a period less than 15s and the average ocean depth of the Atlantic is ~11,000ft. Oddly similar ratios! So it's plausible this 26s wave period is caused by the increase in depth [0]. The abnormally large seismic ampl…

Wave-depth and period are related, waves of 15s or even 26 are much too shallow to be affected by the seabed at those depths.

EDIT: Some back of the envelope physics to see how plausible your hypothesis is:

For deep water waves: wave_speed = gravity * wave_period / 2pi

wave_speed (26 sec period) = 40.56 m/s

wave_speed = wavelength / period => wavelength = 1054 m = 3458 ft.

The effect of the seabed (i.e. shallow water wave physics) is usually taken into account at depths of the order 1/20 the wavelength. That is, when the depth is smaller than 1/20 the wavelength we have to start taking into account the effect of the seabed which makes the dispersion relation of waves non-linear and brings entirely new physics. Of course that 1/20 is not a magic number just a rough figure when the effects of the seabed start to be noticeable.

Unfortunately, we are still off by several orders of magnitude so I would think the effect you describe is unlikely.

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#28

Post by op03 »

jobigoud wrote: post #21
cheriot wrote: post #13

Earlier quoted context omitted.

> But nearly 60 years after the pulse was first observed, no one has managed to figure it out. That may be because, as far as seismologists are concerned, it’s just not really a priority. “There are certain things that we concentrate on in seismology,” explains Wiens. “We want to determine the structure beneath the continents, things like that. This is just a little bit outside what we would typically study … [since]…

Such a weird justification. If they don't know what's causing it how do they know it won't help explain the structure beneath the continent or the deep structure of the Earth.

It's not weird. Its just how a large jungle gets explored by chimps with 6 inch brains. Eye doctors, Astronomers, Painters, Microscopists, Architects etc etc had all been studying light for thousands of years. But it took a bookminder to do some basic 8th grade magnetism and electrical experiments to make a connection.

The jungle is vast and there are only so many curious chimps.

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#29

Post by throwaway_pdp09 »

jobigoud wrote: post #21
cheriot wrote: post #13

Earlier quoted context omitted.

> But nearly 60 years after the pulse was first observed, no one has managed to figure it out. That may be because, as far as seismologists are concerned, it’s just not really a priority. “There are certain things that we concentrate on in seismology,” explains Wiens. “We want to determine the structure beneath the continents, things like that. This is just a little bit outside what we would typically study … [since]…

Such a weird justification. If they don't know what's causing it how do they know it won't help explain the structure beneath the continent or the deep structure of the Earth.

Life is finite. Brainpower is finite. If you feel otherwise, add to the field.

Re: The Earth Is Pulsating Every 26 Seconds, and Seismologists Don't Agree Why

#30

Post by aaron695 »

jusssi wrote: post #23
aaron695 wrote: post #14

Earlier quoted context omitted.

> Why haven’t I heard about this before? It's probably just part of the "Earth's hum", which is waves. (Don't confuse this with the world wide paranormal hum people claim to hear) You probably should have learned of the hum at school, if you did, you'd have probably forgotten. As a 10 year old you'd either find it amazing and think of it forever or just forget. It would be interesting to rank it on the importance lev…

> (Don't confuse this with the world wide paranormal hum people claim to hear) Taking this sort of random swipe at at people who experience this is kind of rude. Even though it's pretty much confirmed it's not a real audio signal coming from outside of a person's body, there isn't quite enough evidence it isn't a real auditory sensation for these people (instead of psychological or "paranormal" issue). I do get the h…

> Taking this sort of random swipe at at people who experience this is kind of rude.

> Even though it's pretty much confirmed it's not a real audio signal coming from outside of a person's body

Why would you not think you have the well documented medical condition Tinnitus?

"The Hum" is "a real audio signal coming from outside of a person's body", except it's not real. (And the first Google result for "The Hum" is this legend, not the vibrations from the oceans hum)

It was on the X-Files for instance - https://en.wikipedia.org/wiki/Drive_(The_X-Files)

William Shatner's The UnXplained - https://www.history.com/shows/the-unxplained/season-1/episod...

I have friends who believe in the paranormal. I don't disagree with them, even if it's medical like this. But I also won't agree with them. I'm not sure if that's cowardice.

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