Ok, I was completely wrong about Iran, but this is shallow, and has to be compression, right at the bulldozer end of the India push. So I'm guessing this is a high PGV earthquake. There are always lots of people everywhere in China, so it's a bad combination. We'll wait for some news.
Update: Huge rocks near the epicentre may indicate a high PGV, but there are lots of pictures of weak housing still standing. We may never know the ground motion.
Update2: All the videos show standard damage. If there was a 'hammer zone' for a super-quake, it would be in the mountains.