Next year there is a possibility for a big increase in numbers of devastating earthquakes around the world, warn scientists. This intense seismic activity will be triggered by variations in the speed of Earth’s rotation. The effects would be most noticeable in heavily populated tropical regions.
It is argued that even though the fluctuations in the Earth’s rotation are going to be small, causing minimal changes in the length of the day by a millisecond, this could still be implicated in the release of vast amounts of underground energy.
The link between the rotation of our planet and the seismic activity was highlighted recently in a paper made by Roger Bilham of the University of Colorado in Boulder and Rebecca Bendick of the University of Montana in Missoula. They presented their study at the annual meeting of the Geological Society of America.
“The connection between the Earth’s rotation and the earthquake activity is very strong. According to this connection we discovered, we are going to have a higher number of intense earthquakes next year”, said Bilham.
Bilham and Bendick based their theory on earthquakes of magnitude 7 and higher, that occurred since 1900. Major earthquakes have been recorded for more than a century which gives them a good record to study and research these connections.
While doing this research, they found five periods with significantly higher numbers of strong earthquakes. The number was up to 25 to 30 intense earthquakes a year, in comparison to the average figure that was around 15 major earthquakes a year.
Together they tried to find correlations between these periods of intense seismic activity and other factors. They soon discovered that when Earth’s rotation decreased slightly it’s followed by periods of increased numbers of intense earthquakes.
“The rotation of the Earth does change slightly. Sometimes only by millisecond a day. This changes can be accurately measured by atomic clocks,” said Bilham.
The researchers found that there had been periods of around five years when Earth’s rotation slowed by such an amount. This happened several times over the past 100 years. Crucially, in these periods was noticeable that they were followed by increased numbers of intense earthquakes.
“The Earth is offering us a five-year heads-up on future earthquakes”, said Bilham.
Earth began one of its periodic slowdowns over four years ago, and this newly discovered link is very important. “Next year we are probably going to see a significant increase in numbers of severe earthquakes. We have had it easy this year. So far we have only had about six earthquakes that caused severe damage, but we could easily have 20 a year starting in 2018.”
Scientist suspect that slight changes in the behavior of Earth’s core could be causing both effects, the decrease in day length and the earthquakes. However this theory is still unclear.
Moreover, it’s very hard to predict where would be the location of these extra earthquakes next year. Bilham said they found that most of these intense earthquakes that responded to changes in day length seemed to occur near the equator, where around one billion people live.