Sunday, March 13, 2011
Geophysicist Richard Gross at NASA’s Jet Propulsion Laboratory in Pasadena, CA says the 8.9 earthquake that struck Japan on Friday shortened the length Earth’s day by a fraction and shifted how the planet’s mass is distributed.
A new analysis of the 8.9-magnitude earthquake in Japan has found the mega tremblor accelerated the Earth’s spin, and shortened the length of the 24-hour day by 1.8 microseconds.
This isn’t the first time a massive earthquake has changed the length of Earth’s day. Major temblors have shortened day length in the past.
The 8.8-magnitude earthquake in Chile last year also sped up the planet’s rotation and shortened the day by 1.26 microseconds. The 9.1 Sumatra earthquake in 2004 shortened the day by 6.8 microseconds.
And the impact from Japan’s 8.9-magnitude temblor may not be completely over.The weaker aftershocks may contribute tiny changes to day length as well.