Earth Changes

Japan quake causes day to get a wee bit shorter

Seth Borenstein
Physorg.org
Sat, 12 Mar 2011 22:37 UTC

You won't notice it, but the day just got a tiny bit shorter because of Friday's giant earthquake off the coast of Japan.

NASA geophysicist Richard Gross calculated that Earth's rotation sped up by 1.6 microseconds. That's because of the shift in Earth's mass caused by the 8.9-magnitude earthquake. A microsecond is one-millionth of a second.

That change in rotation speed is slightly more than the one caused by last year's larger Chile earthquake. But 2004's bigger Sumatra earthquake caused a 6.8-microsecond shortening of the day.

The Japan quake is the fifth strongest since 1900.

Reader Comments

Niall · 2011-03-13T03:43:18Z

Question

Why would NASA be repeating this claim after their equivalent post-Chile one was rubbished last year? [Link]

Ady · 2011-03-13T04:14:00Z

because its NASA! they are the pinical of dis-info! 40 years after the 'moon landings' they are still credited as a source of science just like the US government is credited as a source of political freedom. the game is rigged and the house wins. Even if what they say is right its a fixed hand either way.