This conclusion has been reached by a team led by academic Satoshi Ide of the University of Tokyo (Japan). As if in a bad dream, the moon appears to be triggering major earthquakes , which are more likely to occur during high or spring tides—that is, when our satellite is in its full or new moon phase.
The Moon's effect on Earth was already known, as it exerts a gravitational force that activates the tides and helps maintain the stability of our planet. There is even a popular belief that the Moon influences human feelings and behavior. However, until now, no study had been conducted to demonstrate that it could also play a key role in triggering major earthquakes.
The team of researchers carried out a meticulous study, published in the journal Nature Geoscience , in which they recreated the size and amplitude of the tidal force, an effect of gravity that causes tides, in the weeks leading up to large earthquakes of magnitude 5,5 or higher.
Thus, they found a correlation between tidal forces and large earthquakes , while they did not find such a correlation in smaller earthquakes. This discovery is a significant advance, as it could facilitate the prediction of large earthquakes in the future.
Earthquakes like the 2010 Maule earthquake in Chile and the 2011 Tohoku-oki earthquake in Japan occurred during periods of high tidal range. This suggests a relationship between lunar activity and earthquakes , which could help researchers better understand how earthquakes are triggered and potentially prevent further loss of life during these tragic events.
To reach these conclusions, the researchers analyzed data from three earthquake records covering events in Japan, California, and globally. They evaluated the tides that occurred 15 days before the earthquakes, assigning a number from 1 to 15 to measure the relative tidal stress. This approach allowed them to discover that large earthquakes, such as those in Chile and Japan, occurred during the full and new moon phases, when the Sun, Moon, and Earth align.
In their research, they also found that of 10,000 earthquakes with a magnitude close to 5,5, those that initiated during a spring tide were more likely to reach magnitude 8 or higher. This is a momentous discovery, as it demonstrates that tidal forces can have a significant impact on seismic activity, even on large scales.
How do the Moon and Earth interact?
The relationship between the Moon and Earth is complex. The gravitational force exerted by the Moon not only affects the water in the oceans but also has effects on Earth's crust. Lunar gravity causes the water to rise, creating high tides in areas where the Moon is most directly above the planet's surface. You can also read more about the Moon's characteristics to better understand its influence.
Although the Sun also exerts a gravitational pull on Earth, its distance makes its impact on tides less significant than that of the Moon. However, the combined gravitational pull of the Earth, Sun, and Moon can generate tensions in geological faults that could contribute to seismic activity.
Seismologists have long investigated the relationship between tides and earthquakes, noting that two high tides a day can generate small tremors in specific areas, such as the San Andreas Fault in California. Recent studies, such as the one mentioned above, suggest that the most significant events are related to monthly tides, specifically during the new and full moons.
Additional studies and their implications
Complementary research has found that the number of large earthquakes increases during these special lunar periods. This finding provides new insight into how lunar dynamics might influence Earth's seismic activity.
It's important to consider that while a correlation between tides and earthquakes has been demonstrated, this doesn't necessarily imply a direct causal relationship in all cases. Many factors influence the occurrence of earthquakes, and lunar gravity could act as a trigger under certain conditions, but it's not the only factor at play. To understand more about the planet's structure that may influence this, visit the Earth's structure page.
The need to continue investigating this relationship is crucial. Understanding how the Moon's gravity can influence earthquakes could be a fundamental step toward developing more effective prediction methods, potentially saving lives in earthquake-prone regions.
What do the experts think?
Geology experts, such as Honn Kao, have emphasized that this type of research offers a new way of addressing the complexity of seismic phenomena. The possibility of predicting certain earthquakes in advance could revolutionize our approach to safety in seismically active areas.
However, researchers such as Susan Hough of the U.S. Geological Survey have questioned the relationship between lunar phases and earthquakes. Hough argues that while there are observable patterns, these are often the result of random coincidences rather than a direct causal relationship. She asserts that seismic activity can be manipulated by multiple factors, not just lunar influence.
Therefore, although current research suggests that there may be a significant connection between lunar-triggered tides and large earthquakes, further studies are critical to fully validate and understand this relationship.
The Moon and its seismic activity
In addition to influencing Earth's seismic activity, the Moon itself also experiences earthquakes, known as moonquakes. These lunar seismic events are an active area of ​​study, as they can provide valuable information about the composition and internal structure of our natural satellite.
Research has shown that the Moon is shrinking and experiencing significant seismic activity, especially in its polar region. These observations are relevant for planning future lunar explorations, as they may present challenges for planned manned missions.
