The Supermoon did NOT cause the earthquake

Normally, scientists are meant to be circumspect and reserved about cause and effect. We’re supposed to deal in probabilities, statistics and uncertainties. However, on this occasion, I have absolutely no qualms in saying this: The Daily Mail is wrong. The “Supermoon” had nothing to do with the terrible earthquake off the coast of Japan today.

Ben Goldacre and Phil Plait have already produced some admirable rebuttals to the Mail‘s exploitative scaremongering; these are my thoughts, but I recommend reading the linked posts.

The powerful tsunami that today slammed into Japan’s eastern coast comes just two days after warnings that the movement of the moon could trigger unpredictable events on Earth.

Except none of these “warnings” come from scientists. The only people who took the “Supermoon” seriously were internet conspiracy theorists and the tabloids. And…

Astrologers predicted that on March 19 – a week tomorrow – the so-called ‘supermoon’ will be closer to Earth than at any time since 1992, just 221,567 miles away, and that its gravitational pull will bring chaos to Earth.

An astrologer is the not same thing as an astronomer. A warning from an astronomer should (generally) be taken seriously. A warning from an astrologer isn’t worth the paper it’s printed on.

Others on the Internet have predicted it will cause further catastrophes such as volcanic eruptions and earthquakes.

“Others on the Internet”? Of course, everything that was ever written on the internet MUST be true.*

* Fully aware of the hypocrisy, thank you very much.

However the ‘supermoon’ date is still eight days away. But those that adhere to this particular belief could claim that this was still close enough for there to be some kind of effect.

Ok, as everyone knows, the moon orbits once a month. Once every two weeks, it comes close to the Earth – this is the “perigee” of its orbit – and in between these perigees we have the furthest points: the “apogee”. This means that eight days before the perigee, it will be as far away as possible from the Earth; the exact opposite of a “supermoon”. Its gravity would be weaker, not stronger.

The energy needed to produce an earthquake builds slowly through stress and strain in the rocks where tectonic plates meet, over years or decades. A tiny change in the position of the moon – a change which, remember, happens twice a month – will have virtually no effect compared the constant force of billions of tons of rock pressing against each other.

Two days ago, in an interview with ABC radio discussing the potential impact of the March 19 supermoon, astrologer Richard Nolle, who first coined the term in 1979, said he was convinced that lunar perigees cause natural disasters on Earth.

‘Supermoons have a historical association with strong storms, very high tides, extreme tides and also earthquakes,’ he said.

The only one of those that is true is that “Supermoons” can cause high tides (and even then, it only changes the tidal range by a couple of percent). There is no association between “Supermoons” and storms or major earthquakes. And again, an astrologer is NOT an astronomer.

Natural disasters are unfortunately common. Earthquakes, storms and floods happen with depressing regularity – look hard enough and you can find disasters happening around any supermoon. What’s important is to the look at the disasters that weren’t linked to a supermoon. No scientific study has shown an increase in quakes or storms around supermoons.

What do the actual scientists say?

Dr David Harland, space historian and author, said: ‘It’s possible that the moon may be a kilometre or two closer to Earth than normal at a perigee, but it’s an utterly insignificant event.’

Professor George Helffrich, a seismologist at the University of Bristol was equally dismissive.

‘Complete nonsense. The moon has no significant effect on earthquake triggering.

‘If the moon triggers “big” earthquakes, it would trigger the many of millions of times more “small” earthquakes that happen daily. There is no time dependence of those; hence no moon effect.’


John S Whalley, geoscience programme manager at the University of Portsmouth, agreed there was no correlation.

‘There is no established correlation between variations in the orbit of the moon and either the number or magnitude of earthquakes.

‘It is all too easy, with hindsight, to link major earthquakes to variations in all sort of parameters.

‘The real test is to look at the vast numbers of earthquakes of all magnitudes that occur on a daily basis worldwide.

‘Any correlation with the lunar orbit would have to be established on the basis of this population of earthquakes, not on individual high magnitude events. In need hardly add that no such correlation has been established.’

I would end this post with another glib link to the SMBC comic, but frankly I don’t feel like this the right time for daft jokes. Nor is it the appropriate time for a newspaper with a readership of millions to be giving a platform to charlatans and conspiracy theorists, who seize on a terrible tragedy just to get a little bit of publicity for their pseudoscientific claims.


  1. #1 by Daz on Friday, 11th March 2011 - 22:33 GMT+0100

    “who seize on a terrible tragedy just to get a little bit of publicity for their pseudoscientific claims.”

    Not to mention the journalists and editors who print the damn rubbish, knowing, in all likelihood, that it is rubbish, just to sell a few papers.

    I vote we put ’em in the Big Brother house with the inevitable religious loonies who’ll pop up claiming it as God’s punishment for ‘the gays’ or some such, and let them argue it out.

  2. #2 by Prof. K.S.Nataraj on Monday, 14th March 2011 - 12:59 GMT+0100

    excellent. we need to rubbish the statements by these so called astrologers Scientists and people with scientific attitude and some logical thinking must come openly and expose these fraudsters otherwise

  3. #3 by Man in a Shed on Thursday, 17th March 2011 - 9:11 GMT+0100

    Of course you can’t say this as the full mechanisms for earth quakes aren’t understood.

    We do know that moonquakes are caused by the gravitational interaction with earth.

    I would guess the Earth has complex non-linear dynamics involved with the Core floating in its centre ( again interacting with the moon ). Hence earthquake events wouldn’t need to precisely coincide with Lunar orbits to be triggered by Lunar proximity.

    The argument could be similar to the one where you could say exercise causes heart attacks – when the long term impact of exercise is good, but in the short term it may tip an event over its threshold and cause the cardiac arrest.

    • #4 by atomicspin on Thursday, 17th March 2011 - 9:45 GMT+0100

      The thing is though, if the Moon caused earthquakes, we’d see an increase in quakes every time it came close – which happens twice a month. There is simply no connection between how close the Moon is and the number of quakes measured. If the Moon does have some effect on seismic activity, its effect is so small, and so spread out in time, that you can’t blame any “supermoon” for the quake.

      Moonquakes are interesting, but remember that the Earth weighs 100 times more than the moon does. The effect of Earth’s gravity on the Moon’s surface is much stronger than the effect of the Moon’s gravity on the Earth’s surface – and the largest measured moonquake is 1000 times smaller than the quake that hit Japan. We don’t understand the precise details of how earthquakes happen, of course, but we understand the basic details, and forces due to the Moon’s gravity are tiny compared to other forces acting on the tectonic plates.

      And ignoring all this, of course, remember that this happened one week before the supermoon, when the Moon wasn’t close at all!

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