Previous studies have looked at periods of peak tidal stress, which would be during a new moon. At this point, the Sun and Moon are on the same side of Earth, and their gravitational fields “team up” to pull even more strongly on that hemisphere of the world. This was also enough to apparently initiate the horrifying 2011 Tohoku quake, whose accompanying tsunami smothered much of Eastern Japan.
Although there is no direct evidence linking syzygies of both kinds to the physical rupturing of these major subduction zone faults, the correlation – which isn’t linked to any one particular region of the world – is the strongest on record. It may still be circumstantial evidence, but it’s a very compelling argument that suggests that big things have small beginnings.
“[Our study] suggests that the probability of a tiny rock failure expanding to a gigantic rupture increases with increasing tidal stress levels,” the authors note in their paper. “We conclude that large earthquakes are more probable during periods of high tidal stress.”
There has been an increasing amount of evidence in the last few decades that suggests the gravitational influence of the Moon and Sun could be conspiring to pull apart structurally weak faults that were due to release some stress. The San Andreas Fault, for example, has experienced more than 80,000 small tremors related to the lunar cycle.
If it’s triggering these quakes, then should we attempt to destroy the Moon? Ultimately, no – the Moon may also be stirring tides deep within Earth’s liquid core. Without these tides, we may not have a protective magnetic field shielding us from harmful radiation.
Every cloud has a silver lining.
Iwate prefecture damage in Japan as a result of the 2011 quake and tsunami. yankane/Shutterstock