Japan's earthquake changed Earth's rotation rate day length. The quake shifted earth's axis and shortened the day.
Richard Gross at JPL (Jet Propulsion Laboratory), a NASA scientist, has calculated that Japan's 8.9 earthquake on March 11, 2011 increased Earth's rotation rate. He calculated that the length of the day decreased by 1.8 millionths of a second.
The calculations also indicate that the earthquake should have changed the position of Earth’s axis (around which the mass balances of our planet) about 17 centimeters in the direction 133 degrees east longitude.
The earthquake moved the island of Japan about 8 feet. A small part of Earth's mass was redistributed to increase Earth's rotation rate and decrease the length of the day. Last year's earthquake in Chile caused a similar effect. Richard Gross estimated the magnitude 8.8 earthquake that occurred in Chile last year should have shortened the length of the day at about 1.26 microseconds and shifted the axis of the Earth in about 8 inches.
A similar calculation made after 9.1-magnitude earthquake that struck Sumatra in 2004, said the natural phenomenon should have shortened the length of day 6.8 microseconds and change the axis of the earth about 7 inches.
Gross explained, in theory, any phenomenon that redistributes the mass of the Earth will change the planet's rotation.
"The rotation of the Earth changes all the time not only as a result of the earthquake, but also major effects such as changes in atmospheric winds and ocean currents," he said.
"In the course of a year, day length increases and decreases by about one thousandth of a second, which is a change approximately 550 times greater than the change caused by the earthquake in Japan," he added.
In this regard, he indicated that changes in the rotation of the Earth by earthquakes should have no impact on our daily lives.
"Are perfectly natural and happens all the time."
"People should not worry about them" he said.
Source: Examiner : Scienceray
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