Friday, April 19, 2013

M6.9 earthquake China



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.

2 comments:

Gus83 said...

So USGS calls it a 6.6, and China calls it a 7. On a logarithmic scale, that's a big difference. Do you think they're covering up issues with their building code or construction quality?

Harold Asmis said...

Yeah, you were spam again! They don't like you. The usgs uses distant seismometers, and the Chinese only have locals. These shallow thrusts can produce a big difference. I'm still trying to figure out whether it was a super-quake, and in that case the ground motions would be all out of proportion to the moment magnitude.