My stomach sank when I woke up at 4am in London and checked my mail. I heard about the 6.3 quake in Christchurch. I heard the reports and saw some of the footage. I know it will be hard in the hours and days that follow, but I would strongly recommend anyone, especially those in the area in NZ, to limit the viewings of this footage. Yes, I understand you want to know what is going on, and you want to find out about people you care about. But we know from the evidence of coverage of other disasters that repeated viewing of graphic footage of the event (a) adds no further understanding in terms of pure information, and (b) carries a risk of possible psychological difficulties later on.
Try to limit your exposure to imagery on TV and on the internet. Check in once in a while to see if there is anything new. Probably best to stick to radio, but be careful who else might be listening (small children might get even more upset).
Take care out there.