1989 Loma Prieta quake that hit SF and the surrounding area was a 6.9 with a surfacewave 7.1.
It was 11 miles deep, and struck 80 miles (120km or so) from San francisco and Oakland, yet it fucked shit up hardcore there... collapsing bridges, causing pipes and sewers to burst, and collapsing a ton of buildings. However... it downright flattened Santa Cruz where it hit... that town was dusted, just about.
The 6.3 that hit Christchurch was only 3 miles deep, so it likely had faster ground acceleration. It didnt hit for as long, but the initial jolt of that thing facewrecked the area a little harder than the Loma Prieta quake...