There's actually some interesting visuals that illustrate this showing the difference in ground velocity between the two earthquakes :

2010 Quake: https://www.youtube.com/watch?v=eA5m5PZ5p8E

2011 Quake: https://www.youtube.com/watch?v=KJW7tkTwqXo

And a good explanation vid: https://www.youtube.com/watch?v=aaA1nxYVi6k