The Earth is set to experience a change in the speed of its rotation, which may possibly cause more earthquakes to occur next year.
Are we set to see a surge in earthquakes in 2018?
That may be alarming to hear, especially that bit about the Earth’s rotation changing. And yes, our planet’s rotation is set to slow down sometime relatively soon. However, this is something that cyclically happens. Earth’s rotation does periodically slow down, but only for a few milliseconds. It speeds up afterward to its normal rate of rotation, until the next time it’s due to slow down again.
So you may be asking: if this happens now and then, has it happened sometime before in your lifetime and you were somehow too preoccupied to notice? Earth’s slowing rotation is actually something that we’ll never notice, at least not without specialized instruments. However, one side effect of this slowing rotation seems to be a surge in earthquakes around the world.
Earth's rotation periodically slows down.
According to a new study, there was an increase in earthquakes every about 32 years. Findings showed that the surge in earthquakes happened after Earth’s rotation slowed down. Though we can’t perceive this decrease in speed ourselves, atomic clocks can measure the milliseconds by which the rotation slows.
“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 next year,” said Roger Bilham, one of the researchers. Bilham and his colleague, Rebecca Bendick, analyzed the occurrence of earthquakes with a magnitude of seven or greater since the year 1900. They found a total of five periods of time in history in which 25 to 30 intense earthquakes occurred per year. The rest of the time, however, there was an average of just 15 intense earthquakes per year.
However, the uptick in earthquakes didn’t happen right away after Earth’s rotation began to slow down. The researchers found periods of about five years in which Earth’s rotation slows, which are then followed by a period of more earthquakes than usual.
Researchers have also found that this decrease in the speed of Earth’s rotation lasts for about five years. “It is straightforward,” according to Bilham. “The Earth is offering us a five-year heads-up on future earthquakes.”
Disruptions in Earth's outer core may be causing disruptions in Earth's rotation. [Image by NASA]
Now, it turns out that Earth’s rotation began slowing down over four years ago. “We have had it easy this year,” Bilham said. “So far we have only had about six severe earthquakes. We could easily have 20 a year starting in 2018.”
One pertinent question, of course, is why Earth’s rotation slows down. Scientists don’t actually have a certain answer, but they do have some hypotheses. One, for example, says it’s possible that Earth’s outer core, which is liquid, may sometimes stick to Earth’s mantle. This may then lead to a disruption in the flow of the outer core’s liquid, which would then disrupt Earth’s magnetic field. This may be the reason for the imperceptible changes in the speed of Earth’s rotation. It may also be what’s causing the increase in earthquakes.
Of all the natural disasters that can befall us, earthquakes are the most difficult to predict. We may not be able to tell when exactly these earthquakes will occur next year, but at the very least we can prepare for the possibility that more earthquakes will occur.
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