<p>Edit: This answer refers to the first version of this question which asked about &quot;gravitational waves&quot;.</p>
<p>Typically, the term &quot;gravitational wave&quot; is reserved for distortions (&quot;strain&quot;) in spacetime, in accordance with General Relativity. <a href="https://en.wikipedia.org/wiki/Gravitational_wave" rel="nofollow noreferrer">Gravitational waves</a> are a property of spacetime and can thus propagate in empty space. In contrast, what you measure here are simply <a href="https://en.wikipedia.org/wiki/Seismic_wave" rel="nofollow noreferrer">seismic waves</a>, such as pressure waves propagating through Earth and your setup. In fact, seismic waves are the limiting noise that prevents gravitational wave detectors such as aLIGO to measure at lower frequencies, see e.g. <a href="https://arxiv.org/abs/1604.00439" rel="nofollow noreferrer">this paper</a> for a discussion and plots.</p>

CC BY-SA 4.0
2021-05-10T00:53:55.417Z
We do have seismic signals in some of our measurements, but all of our measurements include a signal at around 3E-5 Hz that is 20 dB above the noise floor. This is a static signal that shows up in every measurement including those from the Continental US, Japan and Hawaii. By your reasoning, seismic events are occuring at the exact same frequency at different times and different places...that would be quite the global seismic event, highly unlikely. The theoretical section first printed on 07/2020 predicts a large signal at this frequency before measurements were made in 11/2021.
Sparks
CC BY-SA 4.0
2021-05-10T00:58:59.400Z
I'm not a Earth Scientist but there are modes where the entire Earth oscillates at. You could get closer to the actual cause of your signal by not only comparing amplitudes, but also the phases. (In any case don't get your hopes up, it's most certainly not gravitational waves)
rfl
CC BY-SA 4.0
2021-05-10T01:53:02.110Z
The gravitational waves detected by LIGO are the result of two pulsars rapidly moving around a common center. The original theory of gravitational waves from General Relativity was rejected by Physical Review journal because it lacked a plausible mechanism for generating waves from the static or moving GR solutions. The binary pulsars each generate static waves through this new  matter-wave model and the Doppler shifted version of those static waves from each pulsar intermodulate and produce base band frequencies that LIGO measures.
Sparks
CC BY-SA 4.0
2021-05-15T22:45:32.727Z
There was a helpful edit to the question which I'd accepted, then I'd made a further edit. I don't think either impacts your already-posted answer negatively, but please have a look. I think the question can be reopened, there's no longer any need for it to be closed hopefully. *Thanks!*
uhoh
CC BY-SA 4.0
2021-05-09T17:44:02.583Z
2021-05-16T12:46:48.027Z
2021-05-16T12:46:48.027Z
rfl
<p>On Earth, around 13,000 oscillations can be measured in the frequency range 1 <span class="math-container">$\mu$</span>Hz to around 200 <span class="math-container">$\mu$</span>Hz. A very strong peak is observed at 22.3643 <span class="math-container">$\mu$</span>Hz. At this frequency the moon deforms the earth and the atmosphere (tides). The moon, the sun and the planets generate further, much weaker resonance frequencies, which are precisely known and tabulated in The HW95 tidal potential catalogue,
<a href="https://publikationen.bibliothek.kit.edu/160395" rel="nofollow noreferrer">https://publikationen.bibliothek.kit.edu/160395</a>. A spectrum can be found in <a href="https://vixra.org/abs/2311.0020" rel="nofollow noreferrer">https://vixra.org/abs/2311.0020</a></p>

CC BY-SA 4.0
2023-11-11T14:27:47.680Z
2023-11-11T14:28:21.543Z
2023-11-11T14:28:21.543Z
9herbert9
<p>Does the Earth exhibit measurable <a href="https://en.wikipedia.org/wiki/Gravity_wave" rel="noreferrer">gravity waves</a>? Note: I'm not asking about <em>gravitational waves</em>.</p>
<p>Some recent experiments looking at low-frequency (3<span class="math-container">$\times 10^{-5}$</span>Hz) accelerometer data are showing some features that might be explained by this. The signal that I and others have measured shows a signal at least 10 to 15 dB above the noise floor that appears to change somewhat based on local geology as determined between measurements in Japan, Hawaii, and the continental US.</p>
<p>Any insight into crustal gravity waves with a period of roughly 9 hours, or other phenomena that might result in reproducible signals like this in accelerometers is appreciated.</p>
<p>Any suggestions for further analysis that might differentiate among different possible explanations is also welcome!</p>

CC BY-SA 4.0
2021-05-09T14:26:17.853Z
This is absolutely legitimate...I am requesting confirmation from other geologists if this is correct. I am not selling anything, I'm just trying to determine what this phenomenon is and inquiring with the broader earth science  community. This is strictly a scientific inquiry.
Sparks
CC BY-SA 4.0
2021-05-14T15:02:04.990Z
@Sparks Earth Science is not totally of Geologists with Geology Majors, go to the help page and read the guidelines, no Self-Promotion, advertising allowed, also no opinions allowed only fact-based Questions and Answers.
Tardy
CC BY-SA 4.0
2021-05-15T22:00:23.160Z
@Fred I think that's overly zealous and a quick edit could have solved the problem, see [this answer](https://earthscience.meta.stackexchange.com/a/1907/6031) Saying this question is about self promotion & advertising is absurd. There are tons of questions here of the form "I saw this phenomenon, could it be real?"
uhoh
CC BY-SA 4.0
2021-05-15T22:12:19.787Z
@MooseSmart edit looks great, *thanks!*
uhoh
CC BY-SA 4.0
2021-05-15T22:14:51.563Z
@Sparks Welcome to Stack Exchange! I think your initial experience here was not a good representation of how well Stack Exchange normally works (see my previous comments above and [my post in meta](https://earthscience.meta.stackexchange.com/a/1907/6031)). It takes a little time to get used to the best way to ask questions here. Since your question has been edited we can start the reopen process. Usually folks can just suggest changes or make them instead of closing which **blocks answers** but sometimes users get in to video game mode and pew! pew! pew! insta-close things. :-)
uhoh
CC BY-SA 4.0
2021-05-15T22:18:53.320Z
@Sparks if you can edit your question further and mention how the phases of the signals you are seeing in different locations relate that will be interesting as well. Earth Science SE certainly supports questions of the type "I saw this phenomenon, could it be X? If not, what else might it be?" but it's not for reporting findings, so I guess it means in this case keep the phrasing more towards the former than the latter. Stack Exchange is open to the whole internet and yet is astoundingly successful and calm (usually). We keep it this way by sticking to certain norms and traditions.
uhoh
CC BY-SA 4.0
2021-05-15T22:57:33.020Z
@Sparks Is there any chance it was consistent with 2.3$\times 10^{-5}$ Hz? A 12 hour period would be consistent with tidal effects https://astronomy.stackexchange.com/a/35562/7982
uhoh
<seismology><data-analysis><gravity><instrumentation>
Does the Earth produces measurable gravity waves?
Sparks
# Does the Earth produces measurable gravity waves?

(Asked by: username_0 on 2021-05-09)

Does the Earth exhibit measurable [gravity waves](https://en.wikipedia.org/wiki/Gravity_wave)? Note: I'm not asking about *gravitational waves*.

Some recent experiments looking at low-frequency (3$\times 10^{-5}$Hz) accelerometer data are showing some features that might be explained by this. The signal that I and others have measured shows a signal at least 10 to 15 dB above the noise floor that appears to change somewhat based on local geology as determined between measurements in Japan, Hawaii, and the continental US.

Any insight into crustal gravity waves with a period of roughly 9 hours, or other phenomena that might result in reproducible signals like this in accelerometers is appreciated.

Any suggestions for further analysis that might differentiate among different possible explanations is also welcome!

**Tags:** seismology, data-analysis, gravity, instrumentation

> **Comments:**
> **username_0**: This is absolutely legitimate...I am requesting confirmation from other geologists if this is correct. I am not selling anything, I'm just trying to determine what this phenomenon is and inquiring with the broader earth science  community. This is strictly a scientific inquiry.  
> **username_1**: @username_0 Earth Science is not totally of Geologists with Geology Majors, go to the help page and read the guidelines, no Self-Promotion, advertising allowed, also no opinions allowed only fact-based Questions and Answers.  
> **username_2**: @Fred I think that's overly zealous and a quick edit could have solved the problem, see [this answer](https://earthscience.meta.stackexchange.com/a/1907/6031) Saying this question is about self promotion & advertising is absurd. There are tons of questions here of the form "I saw this phenomenon, could it be real?"  
> **username_2**: @MooseSmart edit looks great, *thanks!*  
> **username_2**: @username_0 Welcome to Stack Exchange! I think your initial experience here was not a good representation of how well Stack Exchange normally works (see my previous comments above and [my post in meta](https://earthscience.meta.stackexchange.com/a/1907/6031)). It takes a little time to get used to the best way to ask questions here. Since your question has been edited we can start the reopen process. Usually folks can just suggest changes or make them instead of closing which **blocks answers** but sometimes users get in to video game mode and pew! pew! pew! insta-close things. :-)  
> **username_2**: @username_0 if you can edit your question further and mention how the phases of the signals you are seeing in different locations relate that will be interesting as well. Earth Science SE certainly supports questions of the type "I saw this phenomenon, could it be X? If not, what else might it be?" but it's not for reporting findings, so I guess it means in this case keep the phrasing more towards the former than the latter. Stack Exchange is open to the whole internet and yet is astoundingly successful and calm (usually). We keep it this way by sticking to certain norms and traditions.  
> **username_2**: @username_0 Is there any chance it was consistent with 2.3$\times 10^{-5}$ Hz? A 12 hour period would be consistent with tidal effects https://astronomy.stackexchange.com/a/35562/7982  

---

## 2 answers

### Answer by username_3 on 2021-05-09. Score: 2

Edit: This answer refers to the first version of this question which asked about "gravitational waves".

Typically, the term "gravitational wave" is reserved for distortions ("strain") in spacetime, in accordance with General Relativity. [Gravitational waves](https://en.wikipedia.org/wiki/Gravitational_wave) are a property of spacetime and can thus propagate in empty space. In contrast, what you measure here are simply [seismic waves](https://en.wikipedia.org/wiki/Seismic_wave), such as pressure waves propagating through Earth and your setup. In fact, seismic waves are the limiting noise that prevents gravitational wave detectors such as aLIGO to measure at lower frequencies, see e.g. [this paper](https://arxiv.org/abs/1604.00439) for a discussion and plots.

> **Comments:**
> **username_0**: We do have seismic signals in some of our measurements, but all of our measurements include a signal at around 3E-5 Hz that is 20 dB above the noise floor. This is a static signal that shows up in every measurement including those from the Continental US, Japan and Hawaii. By your reasoning, seismic events are occuring at the exact same frequency at different times and different places...that would be quite the global seismic event, highly unlikely. The theoretical section first printed on 07/2020 predicts a large signal at this frequency before measurements were made in 11/2021.  
> **username_3**: I'm not a Earth Scientist but there are modes where the entire Earth oscillates at. You could get closer to the actual cause of your signal by not only comparing amplitudes, but also the phases. (In any case don't get your hopes up, it's most certainly not gravitational waves)  
> **username_0**: The gravitational waves detected by LIGO are the result of two pulsars rapidly moving around a common center. The original theory of gravitational waves from General Relativity was rejected by Physical Review journal because it lacked a plausible mechanism for generating waves from the static or moving GR solutions. The binary pulsars each generate static waves through this new  matter-wave model and the Doppler shifted version of those static waves from each pulsar intermodulate and produce base band frequencies that LIGO measures.  
> **username_2**: There was a helpful edit to the question which I'd accepted, then I'd made a further edit. I don't think either impacts your already-posted answer negatively, but please have a look. I think the question can be reopened, there's no longer any need for it to be closed hopefully. *Thanks!*  

---

### Answer by username_4 on 2023-11-11. Score: 0

On Earth, around 13,000 oscillations can be measured in the frequency range 1 $\mu$Hz to around 200 $\mu$Hz. A very strong peak is observed at 22.3643 $\mu$Hz. At this frequency the moon deforms the earth and the atmosphere (tides). The moon, the sun and the planets generate further, much weaker resonance frequencies, which are precisely known and tabulated in The HW95 tidal potential catalogue,
<https://publikationen.bibliothek.kit.edu/160395>. A spectrum can be found in <https://vixra.org/abs/2311.0020>


---

