Planet Earth's rotation is slowing down and it could have disastrous consequences
Remember how at the end of 2016 we were all thankful that the year was over, looking forward to the inevitable upswing that 2017 would bring? If so, you likely also remember how 2017 somehow took things to a new low, with dreadful news being reported every single day. So next year can only be better, right? Well, there are many things we don't know 2018 will bring, but one thing we do know is that there'll probably be an increase in natural disasters.
Scientists have warned that the number of earthquakes around the world could see a big increase, due to changes in the speed of the Earth's rotation. The fluctuations in the rotation speed are tiny, changing the length of the day by a millisecond at most, but could still potentially release vast amounts of underground energy. This will ultimately trigger intense seismic activity, particularly in the heavily-populated tropical regions of the world around the equator.
This news was brought to the scientific community's attention last month in a paper written by Roger Bilham, from the University of Colorado, and Rebecca Bendick, from the University of Montana. They presented their findings at the annual meeting of the Geological Society of America, where they found a link between major earthquakes and the rotation of the Earth.
“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,” Bilham told the Observer last week. “Major earthquakes have been well recorded for more than a century and that gives us a good record to study”.
Their study looked at earthquakes of magnitude seven and higher since 1900 and they found five periods where there were significantly higher numbers. They searched for correlations between these periods and other factors, finding that the Earth's rotation speed had slightly decreased. Bilham explained:
"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 rotation of the Earth does change slightly – by a millisecond a day sometimes – and that can be measured very accurately by atomic clocks.
"It is straightforward. The Earth is offering us a five-year heads-up on future earthquakes."
The study discovered there were periods of around five years when the rotation would slow over the last century and a half, and the Earth began one of these slowdowns over four years ago – meaning we could see the effects in 2018. Bilham continued:
"The inference is clear. Next year we should see a significant increase in numbers of severe earthquakes. We have had it easy this year. So far we have only had about six severe earthquakes.
"We could easily have 20 a year starting in 2018."
It's unclear why these periods cause or are related to the earthquakes, but scientists suspect that changes in the behaviour of the Earth's core could be causing both effects. There's some difficulty in predicting where the earthquakes will occur, but Bilham stated that most of the intense ones during these periods seemed to occur near the equator, often in heavily-populated areas.