Another sighting recorded on video 30 minutes prior to the quake:

http://www.videosift.com/video/Strange-clouds-in-sky-30-min-before-Chinese-Quake

Aka: a circumhorizontal arc. (http://en.wikipedia.org/wiki/Circumhorizontal_arc) Very pretty.

Any conspiracy nuts in the house - Looks scalar like.

The same phenomena was reported prior to the Tangshan earthquake in China in 1976
http://en.wikipedia.org/wiki/1976_Tangshan_earthquake

That phenomenon is caused by the cloaking device of the alien ship refracting sunlight in the Earth's atmosphere.

The HMS Swampgas?

yeah, similar to 'sun dogs', just icey cirrus clouds, atara is right... chillaxe everybody.

I remember talking with an old professor one early evening and as the sun was setting there were two 'sun dogs' on each side, so I pointed them out to him and was surprised to learn that this 65 year old dude had never seen something like that before. Interesting how one person can miss something another thought was so common.

http://en.wikipedia.org/wiki/Parhelion

Irishman, I have to disagree with you there. It's a confusing topic, but from what I can gather "earthquake lights" are a completely different phenomenon which has not been proven, and may have a very mundane explanation.
http://en.wikipedia.org/wiki/Earthquake_light

All of the photographs and videos of purported earthquake lights show a glow on the horizon which is visible at night(and which would likely be invisible in daylight). Quite different from a circumhorizontal arc. Here's a citation link from the Wikipedia article, which has a collection of videos and stills. To me these seem pretty unconvincing, and I would guess what's shown in the the urban videos are caused by power surges.
http://inamidst.com/lights/earthquake

Another thing you shouldn't confuse this with is what's called "earthquake clouds". That's a term used by people who claim to be able to predict earthquakes weeks in advance by observing the shape of clouds.
http://en.wikipedia.org/wiki/Earthquake_cloud

As for the idea that circumhorizontal arcs can predict earthquakes. . . I guess it would need to happen more then once.

[citation needed]

I'll stick with Atara's explanation until then.