Large and destructive earthquakes are more likely to occur during full moons. The gravitational pull from the moon could influence to the emergence of strong earthquakes, a new study found.
Earthquakes are the most unpredictable forces on the planet and now it seems that they may be actually following a pattern, the gravitational pull between the Moon and the Sun. Scientists from Department of Earth and Planetary Science and the Earthquake Research Institute at the University of Tokyo, Japan has published a study suggesting that the stress this gravitational pull puts on the planet may influence the movement of Earth's geological faults.
For decades, seismologists have long been confused with what triggers major tremors on the planet. They established that the twice-daily high tides could affect tiny tremors.
The new study, however, pointed out that large earthquakes like those which happened in Japan in 2011, Chile in 2010 and Sumatra in 2004, tend to occur around the times when the tidal stress is at its highest. These huge earthquakes triggered large tsunamis that killed hundreds of thousands of people.
In fact, they found that about 9 of the 12 largest earthquakes ever recorded happened on a full moon or new moon.
"This is a very innovative way to address this long-debated issue," Honn Kao, a seismologist at the Geological Survey of Canada and Natural Resources Canada in Sidney, said in a statement.
"It gives us some sense into the possible relationship between tidal stress and the occurrence of big earthquakes," Kao added.
The scientists calculated the tidal stress history on fault lines over the past two weeks prior to huge earthquakes across the globe. They found that the fraction of large tremors increases as the amplitude of tidal shear stress increases.
"This suggests that the probability of a tiny rock failure expanding to a gigantic rupture increases with increasing tidal stress levels. We conclude that large earthquakes are more probable during periods of high tidal stress," the scientists concluded. Their findings were published in the journal Nature Geoscience on Monday, Sept. 12.