For Google USA there's a Onebox containing earthquake informaton, Ionut reports:

Sample query:
http://www.google.com/search?hl=en&q=earthquake&btnG=Google+Search&gl=us

More info:
http://googlesystem.blogspot.com/2009/03/earthquake-onebox-in-google-search.html

http://blogoscoped.com/files/google-earthquake-onebox.png