The day is shorter because of Chile's earthquake

It is possible that the horrific earthquake that shook Chile last weekend made the earth's axis shift shorter.

The ruined scene in the city of Concepcion, Chile due to the February 27 earthquake.Photo: AP .

CNN said that Richard Gross, a geophysicist of the US Aerospace Agency (NASA), used a computer model to understand the impact of the 8.8-magnitude earthquake in Chile on February 27. for the earth.

He noticed that the earthquake caused the earth axis to move about 8 cm. The material of the Earth always balanced distribution around the axis of rotation. So the movement of the shaft can make the day shorter.

The change is not significant, but it will have a long-term effect, because according to Gross's preliminary calculations, each day will take 1.26 milliseconds.

Large earthquakes always shift large amounts of rock and change the distribution of matter on the planet. When the material distribution on the planet changes, its rotation speed also changes. Meanwhile the speed of rotation determines the length of the day.

Scientists use figure skating athletes to illustrate. When the athlete collapses his hand close to his body, he will rotate faster. It is due to the fact that the action of shortening changes the body weight distribution and therefore also changes the athlete's rotation speed.

This is not the first time a shorter day because of an earthquake. According to CNN, the seismic 9.1 on the Richter scale in 2004 created a tsunami in the Indian Ocean that lost 6.8 milliseconds every day.

There are other events that increase the length of the day. For example, if the Three Gorges Dam in China - currently the world's largest hydroelectric dam - is blocked, it could contain 40 km3 of water and change the distribution of matter on earth. Scientists claim that this change will make the day longer by 0.06 millionths of a second.