Venerated by lovers and poets, suspected of bewitching and disturbing our mood, the Moon now has to carry another sanbenito: its influence on the danger of earthquakes. Because when it appears in all its fullness (full moon) and when it is completely hidden (new moon), the risk that the earth’s surface suffers serious tremors seems to increase, according to a study published in the journal Nature Geoscience .
Before, it was already suspected that the most palpable effect of the gravitational force exerted by our satellite, the tides, could have slight consequences on the seismic activity of certain places , but the new research goes further: during the days of the full and new moon – When the so-called “spring tides” occur – earthquakes with a magnitude of 5.5 on the Richter scale are more likely to turn into a very serious earthquake of 8 or more points .
The study authors, led by Satoshi Ide of the University of Tokyo, have analyzed data from three different seismic records, covering Japan, California and the entire world, assigning a number from 1 to 15 the intensity of the tides that there were the preceding days to relate them to the tremors. Thus, they observed, for example, that the catastrophic earthquakes in Chile, in 2010, and Japan, in 2011, took place, indeed, with strong tides .
Researchers speculate that this little added stress sometimes acts as a “nudge” to generate shocks in the friction zone of geological faults , although many other factors are also at play. Authorities in regions at particular risk of earthquakes should not obsess over the lunar calendar , experts advise.
