The planet is entering a five-year period of slow-down where the movement of the molten iron core slows the Earth’s spin.
But the slowdown reduces the centrifugal force and shrinks and tightens the equator, crushing tectonic plates together with unimaginable force.
Anyone living on the planet’s major fault lines – which run though western USA, southern Europe, the Middle East, South America and the so-called Ring of Fire in the Far East – is in serious danger, experts warn.
In the ‘slow-spin’ years, like 2018, the number of major earthquakes more than doubles.
On average the planet sees about 15 major quakes per year, however next year as many as 35 quakes higher than magnitude 7 are predicted.
A magnitude 7 earthquake is formally described as “causing damage to most buildings, some to partially or completely collapse or receive severe damage. Well-designed structures are likely to receive damage. Felt across great distances with major damage mostly limited to 250 km from epicenter.”
A magnitude 9 quake would level every building for hundreds of miles.
But movement of tectonic plates also triggers volcanoes – or supervolanoes. And supervolcanoes have been known to devastate life on Earth.
The currently erupting Mount Agung in Bali was the site of a spectacular ‘super-eruption’ 74,000-years-ago and USA’s Yellowstone Park is sited over one of the planet’s biggest caldera, bang on the San Andreas Fault between the Pacific tectonic plate and the North American plate.
Experts say if the Yellowstone caldera blows then all life on Earth would be at risk from the immediate destruction and lava flows, then subsequent ash cloud which would trigger catastrophic global cooling.
Researchers at the annual meeting of the Geological Society of America produced evidence that periods of slow rotation over the last 100 years have coincided with substantially more earthquakes than average.
Study co-author Roger Bilham, a geophysicist at the University of Colorado Boulder, told science website Live Science: “The numbers of earthquakes that have occurred each year in the past century are well known.
“The changes in Earth’s rotation rate are also well known. All we have done is to compare these two well-known lists of numbers and report an interesting and useful relationship.”
Mr Bilham and his colleague, Rebecca Bendick, a geophysicist at the University of Montana in Missoula, looked at the history of earthquakes of magnitude 7 or greater since 1900.
On average, there were about 15 major earthquakes per year since 1900 but during slow-down periods this figure rises to as many as 35.
NASA tracks the planets spin-speed to fractions of a second and have confirmed the Earth is entering a period of prolonged slower rotation
Mr Bilham said: “Even though the rotation rate changes so little, the size of the mass of the Earth and the inertia are so great, you don’t need a huge change in rotation to have a change in stress.
“We have no information on where these earthquakes will occur, except that they will occur at the world’s plate boundaries.”