A new analysis denies popular belief that large earthquakes tend to happen during certain phases of the moon or at certain times of the year. The study, published in Seismological Research Letters today, confirms that popular belief is incorrect. After matching the dates and phases of the moon to 204 earthquakes of magnitude 8 or greater, dating back to 1600, Susan Hough of the Geological Survey concluded that there is no evidence that the rates of these large earthquakes are affected by the Earth's position relative to the moon. or in the sun. The patterns that some observers see as a link to large earthquakes with specific parts of the lunar cycle “are no different from the types of patterns that would be obtained if the data were completely random,” Hough noted. To avoid identifying clusters of earthquakes within the data that are linked to other factors, he chose to narrow the list to larger earthquakes. Hough saw some unusual "signs" in the data. For example, the highest number of earthquakes that occur in a single day - 16 times - came seven days after the new moon. But this signal was not statistically significant "and the lunar tides would have been at their lowest at this point, so it doesn't make any physical sense," he noted. Hough said the Moon and the Sun cause terrestrial tensions of the Earth and could be one of the stresses that contribute to a small extent to the nucleation of earthquakes. Some researchers have shown that “there are some cases where there are more earthquakes when tidal stress is high. But if you read those documents, you will see that the authors are very careful not to pretend that the data can be used for prediction, because the modulation is always very small. Sooner or later there will be another big earthquake on the full moon, and the tradition will come back, ”Hough said. “The hope is that this will provide people with an in-depth study to aim for, to show that over time, there is no track record of large earthquakes occurring on a full moon.
