Rates of great earthquakes not affected by moon phases, day of year

Credit: CC0 Public Domain

There is an enduring myth that large earthquakes tend to happen during certain phases of the Moon or at certain times during the year. But a new analysis published in Seismological Research Letters confirms that this bit of earthquake lore is incorrect.

After matching dates and lunar phases to 204 earthquakes of magnitude 8 or larger, Susan Hough of the U.S. Geological Survey concluded that there is no evidence that the rates of these great earthquakes are affected by the position of the Earth relative to either the Moon or the Sun.

In fact, the patterns that some observers see as linking large earthquakes with specific parts of the lunar cycle "are no different from the kinds of patterns you would get if the data are completely random," Hough noted.

To determine this, Hough looked at both the day of the year and the lunar phase for 204 large earthquakes from the global catalog, dating back to the 1600s. To avoid detecting clusters of earthquakes within the data that are related to other factors, she chose to look at larger earthquakes because they are less likely to be an aftershock of a bigger .

Looking at only large earthquakes also allowed Hough to pare down the list to a manageable number that could be matched to lunar phase information found in online databases.

Her analysis did turn up some clusters of earthquakes on certain days, but to test for any significance in the patterns she was observing, she randomized the dates of the earthquakes to find out what kind of patterns would appear in these random data. The patterns in the random data were no different from the kinds of patterns showing up in the original data set, she found.

This isn't an unusual finding, Hough noted. "When you have random data, you can get all sorts of apparent signals, just like when you flip a coin, you sometimes end up with five heads in a row."

Hough did see some unusual "signals" in the original data; for instance, the highest number of earthquakes (16) occurring on a single day came seven days after the new . But this signal was not statistically significant, "and the lunar tides would be at a minimum at this point, so it doesn't make any physical sense," she noted.

Hough said that the Moon and Sun do cause solid Earth tidal stresses— ripples through the Earth itself, and not the waters hitting the coastline—and could be one of the stresses that contribute in a small way to earthquake nucleation."

Some researchers have shown that "there is in some cases a weak effect, where there are more earthquakes when tidal stresses are high," she said, "But if you read those papers, you'll see that the authors are very careful. They never claim that the data can be used for prediction, because the modulation is always very small."

The idea that the Sun and Moon's positions in the sky can modulate earthquake rates has a long history, she said. "I've read Charles Richter's files, the amateur predictors who wrote to him in droves, because he was the one person that people knew to write to ... and if you read the letters, they're similar to what people are saying now, it's all the same ideas."

"Sooner or later there is going to be another big earthquake on a full moon, and the lore will pop back up," said Hough. "The hope is that this will give people a solid study to point to, to show that over time, there isn't a track record of big earthquakes happening on a full ."

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More information: "Do Large (Magnitude ? 8) Global Earthquakes Occur on Preferred Days of the Calendar Year or Lunar Cycle?" Seismological Research Letters (2018). DOI: 10.1785/0220170154
Journal information: Seismological Research Letters

Citation: Rates of great earthquakes not affected by moon phases, day of year (2018, January 16) retrieved 18 July 2019 from https://phys.org/news/2018-01-great-earthquakes-affected-moon-phases.html
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Jan 16, 2018
There yeah go again! Spoiling everybody's feverishly drunken gibberish with the icy-cold reality of the Scientific Method.


Jan 16, 2018
"and the lunar tides would be at a minimum at this point, so it doesn't make any physical sense,"
*Known* Physical sense or not, that's odd enough for another look, surely ??

Jan 16, 2018
...tidal motion pushes the plates, at a somewhat steady rate, and, although there can be no doubt that this affects tectonic activity, there is really no way to directly relate this to any specific earthquake. so, moot point... ;-]

Jan 16, 2018
Hey Susan Hough, how've you been?, thanks again for verifying my findings in March 2011, that it was, in fact, a meteor impact and not the NMSZ to cause the events on Dec.. 16, 1811...

...from my studies of the embayment, I have come to more conclusions- the Moon impacted the Tethys sea 13kya, ending the Pleistocene, and a comet hit the Hudson bay, 10.5kya ending the Clovis...

Please see- https://www.linke...ny-hood/

[...get back in touch with me Susan, and we can correct a great amount of misunderstood science and lost history...]

Jan 17, 2018
An interesting article but it does not account for the 7,500 deep Moonquakes that correlated to earthquakes in the research done in 1975 by a NASA geologist. It does not account for the latest algorithms for seismology being used by students in the USA in 2016 that found over 1000 more deep Moonquakes from the same Apollo data that also correlated to earthquakes. Similarly it does not account for the test done in 2016 on the San Andreas Fault by seismologists who found that 100 out of 100 shallow earthquakes matched the earth tide (where the pull of the Moon pulls up the rocks under our feet). The earth tide, according to earthquake prediction experts, pulls up the rocks between 4.5cm and 0.5m each day.

Jan 17, 2018
A3, you do know the difference in Mass between the Earth and the Moon?

And that the difference in Mass means there is a different aggregate of Tidal Forces upon each?

For example, the Lunar Gravity Atractor is 1/6th that of the Earth's Gravity.

The Moon's gravity is tugging at a one pound mass of a rock on the Earth's surface. Against the pull of the Earth's gravity.

The Earth's gravity is tugging at a one pound mass of a rock on the Lunar surface. Against the pull of the Lunar gravity.

Guess which tidal influence is a lot more measurable?

Jan 18, 2018
"A3, you do know the difference in Mass...
...Guess which tidal influence is a lot more measurable?"

[...well, since there are no tides on the Moon... ]

...the Moon has quakes when the tides hit land and vis-versa\...

...the Moon has everything to do with plate tectonics, as it is the originator...
...one full wobble on Earth's axis is approx. 26ky, at the ending of the last cycle the Moon had impacted the Earth breaking apart the supercontinent of Pangaea, this occurred approx. 13kya...

...it appears this planet and its largest satellite are approx. halfway through a processional cycle, as the 26ky and 100ky glacial cycle coincide with the Moon's orbital elements...
...and when another imbalance occurs, such as another supercontinent congealing or maybe too much water/weight at the equator, another impact may occur...

...this appears somewhat of a pattern...

Jan 18, 2018
What Hough doesn't acknowledge is the triggering effect. When an earthquake is triggered, it may be influenced by a small nudge due to the vicinity of the lunisolar path. Thus, she is contradicting recent research by her colleagues at the USGS:

van der Elst, Nicholas J., et al. "Fortnightly modulation of San Andreas tremor and low-frequency earthquakes." Proceedings of the National Academy of Sciences (2016): 201524316.

Delorey, Andrew A., Nicholas J. van der Elst, and Paul A. Johnson. "Tidal triggering of earthquakes suggests poroelastic behavior on the San Andreas Fault." Earth and Planetary Science Letters 460 (2017): 164-170.

and also this Japanese group

Ide, Satoshi, Suguru Yabe, and Yoshiyuki Tanaka. "Earthquake potential revealed by tidal influence on earthquake size-frequency statistics." Nature Geoscience 9.11 (2016): 834-837.

Jan 19, 2018
During large M7.8 quake in Christchurch there were anecdotal reports about its connection with solar activity, but the systematical connection between quakes and solar activity is still dismissed.

No doubt still dismissed, although likely incorrectly.
There are tools that detect these things too.
It should also be noted that NASA is starting a prediction network based on precisely the same mechanisms Suspicious Observers uses to make their predictions. It's electric.

Jan 19, 2018
...there has been a recent step-up in activity...,
...due to the debris storm the solar system has just entered,...
... several comets had impacted the Sun, causing CME's sending out flares impacting Earth's magnetosphere, producing extreme auroras...
...these explosions send out atmospheric acoustic shockwaves at extremely low frequencies with high intensity, producing vibrations between tectonic plates causing further disruption...
...as well as a multitude of meteors coming in, exploding when hitting the extra oxygen at the troposphere, more sonic booms to cause more quakes...

...in fact the majority of tectonic movement is the result of extraterrestrial activity, besides tidal motion from the Moon-, impacts, close passing comets, solar flares,...all can be external crustal stressors, and have yet to find proper recognition...
[I believe...;-]

[note- the Eurasian plate is still well attached to the mantle...]

Jan 19, 2018
clear, concise study that was understandable even by the pseudoscience eu idiots

Jan 19, 2018
Puhleeze, some matronly nurse step up and take away above patient's comicbooks!

Cause their claptrap is leaking out of their diapers and getting all over the internet!

Jan 19, 2018
[-;...you guys always crack me up!...;-]

...just as the Moon pulls up the on the oceans it also pulls up on the tectonic plates, at the compressional boundary, except for at the Eurasian plate, which pulls down on the Moon...

...any number of factors can produce the final triggering mechanism, but every force is building up the tension, the combination of all stressors must be considered in understanding tectonic movement- where, why, when, how,... earthquakes occur...

[or, anything specifically? ;-]]]]]]]

Jan 20, 2018
So K, if I understand your comment, correctly?

When you jump off the edge of a cliff, you expect to float up? Because that Full Moon is visible in the sky?

Oh, and those ocean tides? Are a surface phenomena, acerbated by winds, air pressure, water temperature, currents and geological fixtures such as shoreline contours and bights.

Jan 20, 2018
[no, no, roll back over, it's ok sir Isaac, we got this;-]

...the entire depth of the ocean, a massive bulge, is being pulled upward from the gravitational pull, as water weighs less than land much more pull, just as a constant tsunami, pushing against the plates, from boundary to surface, with an enormous amount of pressure, this spin force is gradually pushing the plates westward, except for Eurasia, which is currently under subduction from the Pacific plate...

[...its all being pushed westward forming another supercontinent...]

...and when the Moon's full or new, combining gravitational pull with the Sun some tides can reach 12-16m [40-50ft], imagine, across almost the entire shelf of the eastern side of the continents, [also more pull on plates during this phase] this is the moment being suggested that an increase in quakes may occur,...
[...make sense?... ;-]

Jan 20, 2018
Hough's abstract consists of the following (in its entirety):


That's all there is in her abstract. Is this silly, considering her USGS colleagues had at least a couple of papers last year that claimed there is a correlation between earthquake events and a lunar fortnightly cycle?

Jan 21, 2018
Look at the USGS earthquake map

-there appears to be a distinct arc of quakes from LA through las vegas, up through utah, yellowstone and ending in northwest Montana. LA is where the Pacific plate is hung up as it travels northward along the San Andreas.

It's almost as if the pressure is so great it's trying to tear off a large chunk of the western part of this country.

I've been watching this for years and I've never seen this much activity.

If you turn on satellite view it does seem to follow a series of features separating terrain types.

If you follow this arc north it appears to join up with a very clear separation which is apparently the Columbia river valley.

I'm sure there must be a name for this great arc? but I can't find one.

Jan 21, 2018
RGO1, you see but you do not understand.

Since the rise of the present Rocky Mountains. Everything west of that uplift consists of straggly lines of the eastern edge of the Pacific Plates being pushed into and upward. Over and over again, for tens of millions of years. That continuing evolution is why you can find fossils of sea-life at the peaks of the Sierra Ranges and the Colorado Plateau.

Why so much of California has such thick layers of sea bottom clay under the soil.

Contrary to cultists predictions of the leftest coasting falling into the Ocean from a big quake. While some shoreline will dip to tsunamis. And Newport Beach will just collapse into the waters. The fools built their town on a pile of dredgings!

Most of the West Coast will be shoved up and inland.

All those rich folk, owning the beachline will sue the rest of us to restore their entitled enclaves to once again block the beaches from us uncouth peasantry.

Jan 21, 2018
The two largest earthquakes of 2017 coincided with peaks/troughs in the polar magnetic cycle of Sun.
Willful ignorance is required to not see the scientifically obvious electrical connection of the Sun and Earth

Jan 22, 2018
RGO1, you see but you do not understand
You addressing me willis? Sorry I was hoping to get a response from a poster who isn't a drooling imbecile.

Jan 24, 2018
The faultline dear readers, lies not in our stars but in our geography.

And you can quote me on that!

Jan 28, 2018
"...There has been a significant up-tick in earthquake and volcanic activity. This in-itself is not overly concerning, however the locations of this seismic cycle may hit heavily populated areas. This cycles chain of events began on January 23rd with the 7.9 magnitude which hit south of Kodiak, Alaska. Since that event a series of aftershocks ranging from 3.0 to 5.6 mag. with a count of over 270..."
...earthquake swarm...

...could not have timed it more perfectly- explosion against the magnetosphere- tectonic activity... [bam!;-]

Jan 28, 2018
...earthquake swarm...

...could not have timed it more perfectly- explosion against the magnetosphere- tectonic activity... [bam!;-]

...went to edit, half my comment disappeared?
http://scienceofc...logists/ [quote is from this link]
Zeba Knight
Published on Jan 24, 2018
"... It occurred about 1:00am Churchill time, when the half-full moon was less bright..."

...extreme auroras directly to earthquake swarm...
...and you can go down my posts [fb, twit, lnkdn,...] and see how many times flares, auroras, meteors,... correlate to earthquake activity, that's knowing when, but where, a much more difficult calculation...

Feb 05, 2018
...and, finally, the reason why-
NASA - National Aeronautics and Space Administration
"...A burst of plasma was captured erupting from a small flare on the Sun by our Solar Dynamics Observatory on Jan. 22. Watch as immediately after the burst the magnetic fields brighten intensely and begin to reorganize:..." http://go.nasa.gov/2EeE7cD

...solar flares [Jan. 22]- explosions against the magnetosphere [auroras] [Jan.24-25]- earthquake swarm [Jan.25-26]...

...CME more than likely the result of a cometary impact... [...to the Sun...]
...space weather effects Earth's weather directly and can cause serious changes within an instant...

[...yes, the truth- "...I'm the one they love to hate!..." ;-]

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