Some Cartago area residents are betting that the Turrialba volcano will produce a major eruption at the next full moon, June 2,
The prediction contains a lot of logic because full moons have a well-documented effect on ocean tides. The high tides are not just because of the moon. The lunar body, when full or brightly lighted, is on the opposite side of the earth from the sun, but the sun also has a strong gravitational influence on tides from the opposite direction.
When there is a new moon, that is the moon is dark, both the moon and the sun are pulling the earth in the same direction.
Seeking a relationship between the moon and volcano eruptions or even earthquakes goes back to antiquity.
Husband and wife volcano experts Steve and Donna O’Meara studied Italy’s Stromboli volcano more than 25 years ago and obtained data that showed a relationship.
They determined that when the moon is closest to the earth during its variable orbit, called perigee, and also at full moon, volcanic activity would be greater.
During their 14 days living on the shoulder of the continually eruption volcano, the pair determined that the greatest spike in volcanic activity occurred at a time between full moon and perigee, according to the National Geographic Society, which supported the expedition.
The most recent perigees for Costa Rica were March 19, when the moon was just 222,189 miles away, April 16 (224,325 miles) and May 14 (227,444 miles).
The next close approach is June 9 when the moon will be 229,731 miles away or 369,716 kilometers.
Although the mountain is perking all the time, a chart of the major eruptions at Turrialba seems to support the conclusions of the O’Mearas. Four of six significant eruptions took place between the full moon and the lunar perigee. That theory suggests that a major eruption might take place sometime between June 2 and 9.
The O’Mearas probably would be the first to say that eruptions are the result of many factors. Gravitational influences are probably just a part of the puzzle.