The speed of rotation of the Earth a little more quickly after a big earthquake in Japan on Friday (11 / 3).
An earthquake measuring 9 on the Richter Scale (SR) that occur in Japan causing the Earth's mass distribution changes because of plate movement and the collapse of rock in the Earth's skin. That's what makes the speed of rotation of the earth to be a little faster and humans have a shorter day. "The speed increased 1.8 microseconds," said Richard Gross, geophysicist from NASA's Jet Propulsion Laboratory in Pasadena, USA, as reported by Space.com.
Previous analysis of the quake affected only 1.6 microsecond rotational speed, but recent data suggest that the greater strength.
The effect is much smaller than the annual variation. The length of one day or time of rotation of the Earth is 24 hours or 86,400 seconds. Long day for about 1000 microseconds this varies depending on season variation of Earth's mass distribution.
Changes in the rotation by an earthquake like this is not the first time happening. Aceh Earthquake of 2004 for example, shorten the day as much as 6.8 microseconds. While the earthquake in Chile shorten the day 1.26 microseconds.
Gross said that this change has not been completed. Aftershocks could also change the rotation. "Aftershocks could also change the rotation time. But because the power of smaller aftershocks, the effect is also smaller," he explained.
In theory, Gross said, anything that affects the Earth's mass distribution will impact on the rotation. Earthquake reported little movement of the earth's rotation speed is typically about 1604 km / hour.
However, from Indonesia astrophysicist who worked at the Max Planck Institute for Astronomy, Johny Setiawan, not too confident with that opinion. According to him, in short day length can only occur if there are effects from the outside world. "If Earth asteroids fall so that its mass increases, the length will change today," he continued. He said that if the mass of the earth stays the same it should be the speed of rotation and duration of the rotation will also remain the same.
News from:National Geographic
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