The moon might cause earthquakes on Earth, new evidence shows

It’s long been argued that ‘tidal stress’ might be to blame for earthquakes, but evidence for it has proved elusive

The Tohoku earthquake and resulting tsunami that rocked Japan in 2011 happened around a time of high ‘tidal stress’ (Kazuhiro Nogi/AFP/Getty)

The moon could cause huge earthquakes because of the stress it puts on our planet, according to new research.

Scientists have long suspected that the moon might play some part in the major earthquakes that strike across the world and often cause huge amounts of death and destruction.

But until now they haven’t been able to prove it, and no connection between our moon’s activity and those quakes has been established.

High tides are usually just caused by the gravitational pull of the moon, which moves the ocean’s water.

But twice a month, when the moon is new or full, the tides are especially high – the moon, earth and sun line up together and lead to an extra-high “spring” tide.

When that happens, it might lead to extra stress on the Earth’s surface and strain the faults that lead to earthquakes, the new study – led by Satoshi Ide from the University of Tokyo and published in Nature Geoscience – suggests. Scientists have long held that might be true – but never been able to be sure.

The scientists worked that out by looking at the amount of stress that the tides can put on those geological faults, by using information gathered from recent big earthquakes.

They found that very large earthquakes – such as those in Sumatra in 2004, 2010 in Chile and in Japan in 2011 – tend to happen around the times that the tidal stress gets at its highest. The scientist discovered that nine of the 12 biggest quakes on record happened near or on full or new moons.

That discovery could help people forecast when such very big earthquakes are about to happen. But even though the correlation might exist, whatever the moon is up to there is a tiny chance of such an earthquake, so it might prove hard to predict on that basis.

It isn’t clear that the same effect happens for smaller earthquakes.