Earth’s Mysterious Hum Explained

Scientists have long known that earthquakes can make the Earth sing like a bell for days or months. However, in the late 1990s, seismologists discovered the world also constantly vibrates at very low frequencies even when there are no quakes. This so-called microseismic activity is too faint for humans to feel.

more…

could be the dinah moe humm.

Big Earthquakes Might Calm the Earth

The biggest earthquakes make the Earth ring like a bell. But do earthquakes that rock the world increase the risk of new temblors?

Not by much, according to two reports presented today (April 19) at the Seismological Society of America’s annual meeting in Salt Lake City. In fact, one recent quake near Sumatra, Indonesia, seemed to actually quiet global earthquakes.

from the first link

Using computer models of the ocean, winds and seafloor, the scientists found that colliding ocean waves could generate seismic waves that take 13 seconds or less to complete one ripple. When it came to slower waves, they found that ocean waves moving over the seafloor could generate seismic waves with a frequency of 13 to 300 seconds. Most of the mystery hum comes from these longer waves. The pressure of these longer ocean waves on the seafloor causes most of the Earth’s bell-like ringing, the researchers said.

CrazyNeutrino said:

from the first link

Using computer models of the ocean, winds and seafloor, the scientists found that colliding ocean waves could generate seismic waves that take 13 seconds or less to complete one ripple. When it came to slower waves, they found that ocean waves moving over the seafloor could generate seismic waves with a frequency of 13 to 300 seconds. Most of the mystery hum comes from these longer waves. The pressure of these longer ocean waves on the seafloor causes most of the Earth’s bell-like ringing, the researchers said.

Good. I’d heard some ten or more years ago that this hum was caused by the movement of the ocean. But I hadn’t realised that there were problems with frequencies in the range of 13 to 300 seconds.

It has forgotten the words

dv said:

It has forgotten the words

Well it is getting on a bit.

other planets with water could be making these bell sounds as well

I read the first linked artical.

I don’t understand the ‘bell analogy’

Aquila said:

I read the first linked artical.

I don’t understand the ‘bell analogy’

It’s a misprint..

Ring like a ball

Or it refers to Schumann resonances

Or even The Hum

ring like a bell=reverb.

ChrispenEvan said:

ring like a bell=reverb.

I am suddenly thinking of Colette.

ChrispenEvan said:

ring like a bell=reverb.

Ploise exlain.

once the clapper has struck the bell still rings, that is reverb.

ChrispenEvan said:

once the clapper has struck the bell still rings, that is reverb.

Does not a bell resonate?

produce or be filled with a deep, full, reverberating sound.
“the sound of the siren resonated across the harbour”

ChrispenEvan said:

produce or be filled with a deep, full, reverberating sound.
“the sound of the siren resonated across the harbour”

So what’s the earth’s fundamental frequency?

Reverberation is the collection of reflected sounds from the surfaces in an enclosure like an auditorium. It is a desirable property of auditoriums to the extent that it helps to overcome the inverse square law dropoff of sound intensity in the enclosure.

the enclosure is the earth.

why would it have a fundamental frequency when it isn’t solid and has varying densities?

ChrispenEvan said:

why would it have a fundamental frequency when it isn’t solid and has varying densities?

So nothing like a bell then.

it’s an analogy.

ChrispenEvan said:

why would it have a fundamental frequency when it isn’t solid and has varying densities?

Well, the Earth is mostly solid. And bells have varying densities (granted not such a large variation, but also bells don’t have anywhere near as much mass.)

ok, it’s nothing like a bell but like something identical but has a different name.

ChrispenEvan said:

ok, it’s nothing like a bell but like something identical but has a different name.

wtf?

it’s a shakespeare reference.

Sorry, I don’t get it.

The earth goes Ohhhmmmmm in perfect resonance with Tibetan Mystics.

AwesomeO said:

The earth goes Ohhhmmmmm in perfect resonance with Tibetan Mystics.

:)

(I get that one.)

:) :) :)

some claim that shakespeare wasn’t the author of the plays attributed to him. they were written by someone else using his name. see anti-stratfordians.

Ah, I see now. Thanks.

Michael V said:

Ah, I see now. Thanks.

I knew a geologist would have the answers.

Ian said:

Michael V said:

Ah, I see now. Thanks.

I knew a geologist would have the answers.

Seriously, I thing the Earth could have a fundamental frequency. It’s likely to be very low…

Michael V said:

Ian said:

Michael V said:

Ah, I see now. Thanks.

I knew a geologist would have the answers.

Seriously, I thing the Earth could have a fundamental frequency. It’s likely to be very low…

A bit over 1 minute according to some.

Michael V said:

Ian said:

Michael V said:

Ah, I see now. Thanks.

I knew a geologist would have the answers.

Seriously, I thing the Earth could have a fundamental frequency. It’s likely to be very low…

If you made a basketball sized earth slightly pears shaped with a soft but heavy centre, ballistic gel oceans, make some dense spots, simulate the plates, throw in some fractures and holes and hit it with a hammer….

what is a frequency of one minute?

AwesomeO said:

Michael V said:

Ian said:

I knew a geologist would have the answers.

Seriously, I thing the Earth could have a fundamental frequency. It’s likely to be very low…

:)

(Or get dv to calculate it. I wouldn’t be surprised if he had already done that.)

If you made a basketball sized earth slightly pears shaped with a soft but heavy centre, ballistic gel oceans, make some dense spots, simulate the plates, throw in some fractures and holes and hit it with a hammer….

ChrispenEvan said:

what is a frequency of one minute?

Cycle per

ChrispenEvan said:

what is a frequency of one minute?

A stoned woodpecker?

how many cycles?

ChrispenEvan said:

what is a frequency of one minute?

1/60 Hz.

~0.016666666666666666666666666666667 Hz

ChrispenEvan said:

what is a frequency of one minute?

0.017 Hz

60Hz surely?

Michael V said:

ChrispenEvan said:

what is a frequency of one minute?

1/60 Hz.

~0.016666666666666666666666666666667 Hz

Tsk, tsk, tsk. Significant figures, MV, tsk, tsk, tsk.

:)

ChrispenEvan said:

60Hz surely?

Frequency is the reciprocal of time.

yeah. though a frequency of one minute tell you nothing.

ChrispenEvan said:

yeah. though a frequency of one minute tell you nothing.

Well I understood the question as one minute being the period of the wave, In that case the frequency is 0.017 Hz.

sibeen said:

Michael V said:

ChrispenEvan said:

what is a frequency of one minute?

1/60 Hz.

~0.016666666666666666666666666666667 Hz

Tsk, tsk, tsk. Significant figures, MV, tsk, tsk, tsk.

:)

Hey! I did use an “approximately” symbol.

so the frequency is .017 Hz not one minute?

Michael V said:

sibeen said:

Michael V said:

1/60 Hz.

~0.016666666666666666666666666666667 Hz

Tsk, tsk, tsk. Significant figures, MV, tsk, tsk, tsk.

:)

Hey! I did use an “approximately” symbol.

Had I had my geologist’s hat on (instead of a mathematicians hat at that point in time), I’d‘ve said “~0.02” Hz.

I’m glad you agree.

:)

as i am.

ChrispenEvan said:

so the frequency is .017 Hz not one minute?

Yes.. very mysterious

but does it though or is it just speculation?

ChrispenEvan said:

so the frequency is .017 Hz not one minute?

1 Hz is one cycle per second.

2 Hz is two cycles per second.

0.5 Hz is half a cycle per second = one cycle per two seconds.

1/60 Hz = ~0.0167 Hz is 1 cycle per 60 seconds = 1 cycle per minute.

Michael V said:

Michael V said:

sibeen said:

Tsk, tsk, tsk. Significant figures, MV, tsk, tsk, tsk.

:)

Hey! I did use an “approximately” symbol.

Had I had my geologist’s hat on (instead of a mathematicians hat at that point in time), I’d‘ve said “~0.02” Hz.

?

The 60 is two sig figures. 0.02 is one, if I remember correctly leading zeros are discounted; so my 0.017 is the correct answer!

hopes I’m not wrong

:)

CPS hasn’t been used for years.

ChrispenEvan said:

CPS hasn’t been used for years.

Si :)

sibeen said:

Michael V said:

Michael V said:

Hey! I did use an “approximately” symbol.

Had I had my geologist’s hat on (instead of a mathematicians hat at that point in time), I’d‘ve said “~0.02” Hz.

?

The 60 is two sig figures. 0.02 is one, if I remember correctly leading zeros are discounted; so my 0.017 is the correct answer!

hopes I’m not wrong

:)

Significant figures relate entirely to the accuracy of the measuring instrument. Since none was defined, we are all correct.

i know what the things are just no good at the working shit out side. even easy stuff.

Could I rephrase my explanation to help out?

nah, it is just a number blindness. i’m a word person.

(I must admit to not being metricated for fuel economy. Litres per hundred kilometres is not only an inverse function of miles per gallon, but it has another factor.)