According to Dr. William Kaufmann, director of the Griffith Park Observatory, the moon and the sun pull the Earth in opposite directions during a total lunar eclipse. This pulling on the Earth changes its shape from a sphere to a more oblong figure; it is as if the planet is being squeezed. These forces of gravity and tidal stresses, which are created when the moon, Earth, and the sun are aligned, may trigger earthquakes. That being noted, only a few of the total lunar eclipses have been followed by a significant increase in seismic activity.
However, the total lunar eclipse of Sept. 27-28, 2015 was different:
- It featured a supermoon, which is 220,000 miles away instead of 250,000 miles, and the closest the celestial body has come to the Earth this year. So it looks 14 percent larger and 30 percent brighter than normal.
- This was the last total lunar eclipse of a tetrad (four lunar eclipses six months apart without any partial eclipses in between). The tetrad began on April 15, 2014.
- This was only the fifth tetrad since 1900.
- The combination of the supermoon and the total lunar eclipse is rare. The last one was in 1982 and the next one will not be until 2033.
This most recent total lunar eclipse was followed by more than 121 earthquakes, over a 2.8 magnitude, reported around the world in less than 24 hours. The most significant earthquake had a magnitude of 6.0 in Jujuy Province, Argentina. The quake hit at 15:28 GMT and was 219 km deep at its hypocenter. Two 5.4 magnitude tremors hit San Antonio De Los Cobres and Jujuy, Argentina at the same time. However, the British Geological Society states that the evidence of earthquakes occurring due to phases of the moon has been found to be merely coincidental.
Some scientists are certain that the moon affects the Earth as the planetoid is known to alter the tides and a total lunar eclipse impacts the seabed. The water will be heavier as the tides rise higher and fall harder, changing the pressure in the seabed. Based on these scientific facts the idea the celestial body could also trigger earthquakes seems legitimate. However, there is science, which does not agree.
The pressure the tides put on the floor of the sea is not as significant as the tectonic forces that move the plates. Also, scientists have not seen a link between the severity of an earthquake and the maximum tides. A supermoon only increases the tide height by 10 cm.
Gemma Lavender, from the Royal Astronomical Society, says the claims stating the moon being closest to Earth will cause tectonic and volcanic activity is false. That being said, the gravitational pull of the planetoid and the sun does cause the crust of the Earth to rise and fall; this event is referred to as a “land tide.” Land tides can rise up to 20 cm at the North and South Pole. This would lead one to assume that the moon and the sun can cause earthquakes, however, the Earth gravitationally affects the celestial body and induces moonquakes instead.
The Earth has 81 times the mass of its satellite, making it highly unlikely the small celestial body could cause an earthquake of any size. Nonetheless, there are scientific papers written on both sides of this controversy. Studies have also been conducted concluding that the moon-induced land tides can trigger earthquakes.
As a matter of fact, a study conducted by Lyndie Chiou, with the Research Pipeline, showed when both celestial bodies are on the horizon, there was a notable decrease in tectonic activity. It is believed this happens because when the sun and moon are together on the horizon the gravitational pull on the earth is horizontal, therefore, pushing together fault lines.
Scientists cannot agree on what impact the planetoid truly has on the Earth. Although science has not discovered what the relationship is between a total lunar eclipse and seismic activity, Argentina may not accept the statement from Lavender that significant changes of the moon do not impact the Earth, at least in this rare instance.
By Jeanette Smith
Space.com: 10 Surprising Facts About Lunar Eclipses
Earthquake Report: Earthquakes in the World on Sept. 28, 2015 (M2.9 or More)
Daily Mail: Blood Moon and Lunar Eclipse Features Closest Possible Lunar Approach to Earth
IFL Science: Fact Over Fiction On the Apocalyptic Super Blood Moon
IBT: ‘Supermoon’ 2015 Live Streaming Information: Will Full Moon Cause Earthquakes, Volcanic Eruptions?
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