The Moon and the Moonie

Part I: The Moon

This is getting a bit old. Time and time again, someone bops along with the idea that the Moon or the sun causes an increase in seismicity. They climb up on their soapbox and thump their chest denouncing the world (that would be the rest of us) are blind to the obvious correlation. That we will all suffer ruination if we don’t heed their warnings or suffers some calamity akin to a slow and brutal death.

Hey, sounds like fun. Let’s play.

Here is a plot of all earthquakes greater than Magnitude 4.5 as listed on the USGS website from 1973 to 2010.

Image by GeoLurking.

Wow, that look a bit compelling. How about the power distribution across that same data?

Image by GeoLurking.

Well… that seals the deal. Right?

Not so fast.

First, I would like to point out that there is some research that points to a lunar influence in the activity of certain already seismically active regions, but that this research is founded on actual science. The effect is ephemeral and buried in noise. This is not intended to debunk that research, only to illustrate just how misleading some of the source data is, and how easy it is to jump to conclusions.

Now here is the nugget-o-truth that most people tend to miss:

The longer that the Moon spends at a specific location, the more likely it is that quakes will occur while it is at that location.

The Moon completes an orbit around the Earth about every 27.321 days. All orbits have a Perapsis (closest point on orbit) and an Apoapsis (furthest point). At perapsis the Moon is at it’s highest rate of speed at about 1.076 km/s.1 At apoapsis, it is moving at 0.964 km/s1. Obviously, this speed is not constant. The period of the Lunar orbit is 27.321582 days2 . The Moon goes through a full phase cycle in about 29.53 days3. That’s almost the same period… but it’s not. Couple this with the dynamics of an elliptical orbit, and you get this odd characteristic.

Image by GeoLurking.

This is the dwell time of the Moon on two separate phase cycles. Notice that the curves, though similar, do not match. This is due to the ‘not quite the same’ durations of the phase cycle and the orbital period. Also notice that the amount of time spent at the New and Full phases is longer than at mid phase.

Let’s take a look at several cycles in order to see if there is a pattern.

Image by GeoLurking.

Sure enough… that orange is the plot of several phase cycles. The blue is an average of what is seen at that phase over those same cycles. (the average of the orange curve). We can go a step further and run this through a curve fitting program in order to see if there is a function that matches.

Image by GeoLurking.

That’s pretty good… but note the end points, even though the curve is a good fit, it leave enough uncertainty on the ends to make it mostly useless. I provided the plot mainly since I pissed away about two and a half hours in Erueqa’s “Formulize” in order to find it. (it’s a really great program though).

Taking the idea of using the mean of the curve to calculate a correction factor, and using the 1000 bin average from the previous plot (the one with the orange and blue), we can apply that to the quake count curve.

Image by GeoLurking.

Err… where did the trends go? Okay, maybe the power curve will still show the significant signal.

Image by GeoLurking.

Hmm… not looking so good.

There is still an artifact in there… at least it seems to me like there is an artifact in there… but it’s small. So small that the last thing I would do would be to stand on a soap box preaching at people about it.

Part II: The Sun and the Moon

I realize that some people are adamant about the seismic connection with the Sun and the Moon. I also realize that I have pointed out a few issues with making this connection. One might argue that I was being very selective in presenting the data… okay, fair enough.

Here are some more plots that may, or may not, show a connection. You be the judge.

Image by GeoLurking.
Image by GeoLurking.
Image by GeoLurking.
Image by GeoLurking.

Nothing there that really jumps out at ya eh? Okay, a few more:

Image by GeoLurking.
Image by GeoLurking.

Do note that the apparent dwell time of the Sun at mid Winter and Mid Summer really stands out in that last plot. By the way, see those horizontal bands? Those are the latitudes of seismically active areas.


Image by GeoLurking.
Image by GeoLurking.

Again, the bands equate to known active areas… this time in longitude.

You may think me an ass for not believing in the Sun-Moon-Earth connection. That’s your prerogative. But unlike some, I actually went out and looked for myself. I’m not one to buy a pig in a poke. Personally, I don’t see it in the data. If your numeric skills are better, knock yourself out. I could stand to learn a thing or two while reading it. But if it’s BS, I’m not gonna buy it.





2 thoughts on “The Moon and the Moonie

  1. okay how does an opera singer break a glass. the strength of the voice about 120db..through the density of air….. the internal strength of glass( a supercooled liquid) immensely stronger.
    yet the glass breaks when the sympathetic vibrations are matched.or frequencies are additive smashboomcrash If we are to measure the absolute strength of the solution whether it be gravitational strength of the moon and the earth is to misunderstand the situation.
    okay the width of crust to diameter of earth 10-70km to twelve thousand lets say on average 1 to 6000-6600 ratio. and the ratio of gravity moon to earth 1 to 6 round about. awful lot of 6s. this means even though the gravity is one sixth of the earth the grav field of the moon is broadly sympathetic to the ratio of the crust to diameter. also if you check the above page you will see anomalies.
    Any surfer on the planet can tell you when the rising moon is low in the sky surf is up. swells appear from nowhere with the complete absence of storm systems. gravitational waves.

    low c on the piano will vibrate hi c. hi c …low c.

    the effect flows on. when the vibration of the grav field reaches sympathy the thixotrophic lava finds itself able to flow.(pretend the ketchup is lava. turn the bottle upside your vibrating phone on the bottle and wait for the eruption.)
    I see geolurking and carl frantically quoting absolute figures but missing the david and goliath point.
    finally you include the wildly fluctuating sun and its additive to the earth moon grav field. vibrating all those 667hz and super and subsets of that frequency in a standing gravwave.

    Its quite a male perspective. brute strength. or the strong vs weak argument.

    • I’m sorry, but I believe you are the one who misses the point. I’ll give you a few hints but it’s only fair to warn you that they will be useless to you without at least a High School level education and you will have to look things up and think for yourself.

      First – Try to figure out why a singer can’t break an earthenware cup, then explain in what way the Earth’s crust differs from a crystal glass.

      Second – “Wildly fluctuating Sun”. Excuse me? The Sun’s luminosity varies about 0.1% between min and max over the 11-year cycle. Now answer this: The Earth’s orbit round the Sun is not circular but elliptic. How much does the amount of light/energy received from the Sun vary over the year? More or less than 0.1%?

      Third – just a piece of advice. If you know nothing or next to nothing about a subject, don’t give yourself airs. It will only serve to expose your ignorance and make you look like the fool you are.

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