Jump to content

Length of the day shortened by Chilean earthquake


bascule

Recommended Posts

http://www.csmonitor.com/Science/Discoveries/2010/0303/Chile-earthquake-shortened-Earth-s-day-NASA-thinks-so

 

The Chilean earthquake displaced enough of the Earth's mass to affect its axis and shortened the length of the day by approximately one microsecond.

 

I heard a great NPR interview with a NASA geophysicist about this. Apparently they managed to perform this calculation using seismic data alone.

Link to comment
Share on other sites

I heard a great NPR interview with a NASA geophysicist about this. Apparently they managed to perform this calculation using seismic data alone.

 

This?

 

And the USNO scientist they interviewed? What is he, chopped liver? ;):D

 

(I'll tell. He works a few doors up the hall)

Link to comment
Share on other sites

This effect is similar to pulling your arms closer to you to spin faster. Conservation of angular momentum means you spin faster -- but this does not generate any more angular momentum. Earth is losing angular momentum (it is being transferred gravitationally to the moon via tides). We will eventually match spins with the moon's orbit, so that one side of Earth faces the moon as today one side of the moon always faces Earth.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.