Earthquakes are one of the major natural disasters that human beings have not been able to decode so far. For sure, no one can ever forget the 2001 Gujarat earthquake that claimed the life of around 20,000 people. There are many reasons of the cause of earthquake including tectonic movements in the Earth's crust. Well, slowing down of the Earth’s rotation can also cause the earthquakes. Shocking, isn’t it? This must not be known by many. Right? Earth’s rotation is slowing down as the Moon moves farther away from the planet and it could cause major earthquakes, reported express.co.uk.
Matthew Funke, solar system ambassador for NASA’s Jet Propulsion Laboratory, said that the Moon’s gravity creates a tidal bulge on the Earth. This bulge attempts to rotate at the same speed as the rest of the planet.
“As it moves ahead of the Moon, the Moon attempts to pull it back. This slows the Earth’s rotation down,” Matthew Funke noted on Q+A website Quora. He further said, “One of the rules of the Universe is that ‘angular momentum’ can’t go anywhere — even if individual pieces speed up, slow down, or change direction, the sum total of angular momentum cannot change.”
“The Earth loses angular momentum when the Moon slows it down, so the Moon has to gain it — and it does, by moving further away in its orbit. The Moon is currently receding from the Earth by about one and a half inches per year. This could lead to major earthquakes down the line,” he underlined.
It is worth mentioning here that a slower rotating Earth leads to stronger and more frequent earthquakes, however, the reason is unclear.
A research carried out by Roger Bilham of the University of Colorado in Boulder and Rebecca Bendick of the University of Montana in Missoula observed the earthquakes with a magnitude higher than seven since 1900.
Roger Bilham and Rebecca Bendick found five years since the turn of the 20th century where there were significantly more magnitude 7.0-plus earthquakes – all of which were years that earth’s rotation speed had slowed down slightly.
Bilham said, “In these periods, there were between 25 to 30 intense earthquakes a year. The rest of the time the average figure was around 15 major earthquakes a year.” “The correlation between Earth’s rotation and earthquake activity is strong and suggests there is going to be an increase in numbers of intense earthquakes,” he added.
According to Physicist Paul Walorski, this is expected to happen for billions of years. “The slowing rotation of the Earth results in a longer day as well as a longer month. That’s been projected to happen once the day and month both equal about 47 (current) days, billions of years in the future,” he explained on physics forum PhysLink.