New Delhi: Slowing down of the earth’s rotation can cause devastating earthquakes across the world the next year, geologists have warned through a thesis submitted to the Geological Society of America. Retardation in the speed with which our planet rotates causes “intense seismic activity”, these scientists say.
India is particularly vulnerable, as these highly probable earthquakes will hit the “tropical, equatorial regions” the hardest — as per the calculations of scientists.
The number of earthquakes in the year 2018 could be between 25 and 30, say Roger Bilham of the University of Colorado in Boulder and Rebecca Bendick of the University of Montana in Missoula, who presented their paper at the annual meeting of the Geological Society of America.
The slowdown in the angular velocity of the earth is negligible otherwise, where the earth is taking a millisecond or two more to complete each rotation. That’s enough to release considerable energy from the interiors of the earth. That’s because the angular velocity-seismic activity correlation is strong, the scientists say.
The reason for the correlation is, however, unexplained. It is presumed that some activities in the core and mantle of the planet lead to the reduction in its angular velocity which, in turn, causes an upsurge of the magma (molten matter in the second layer of the earth) towards the surface — that may lead to a volcanic eruption or an earthquake.
Bilham and Bendick studied all earthquakes that measured greater than 7 on the Richter Scale since 1910 to reach this conclusion. They noticed that the five periods that registered high frequencies (25 to 30) of earthquakes coincided with the slowing down of the rotation of the earth.
The periods in which about 15 odd earthquakes a year were recorded did not correspond to a noticeable reduction in the angular velocity of the earth.
Atomic clocks were used to measure the speed of rotation of the earth — for the sake of accuracy — Bilham said.
This slowdown occurs over a period of five years, the scientists observed. Those five years wherein the fifth year witnesses massive earthquakes every time. The observation of this pattern could lead scientists to devising an accurate method of predicting earthquakes, which has not been possible this far.
There have been about six earthquakes this year where the magnitude was 7 or above on the Richter Scale. The figure could rise to 25-30 in 2018, the scientists have warned.
Hindusthan Samachar/Surajit Dasgupta