Doesn't seem like our journalists are asking serious questions as to why these newish buildings are not able to survive these earthquakes. Queensgate cinema, readings car park, state services. Surely they will launch an enquiry. Someone's head needs to roll. It's embarrassing.
But these buildings did what they needed to do and survived the earthquake. I'm not an engineer but from what I gather a building isn't designed to go through an earthquake unscathed, it's designed to get through an earthquake with it's occupants still alive. So modern buildings move in an earthquake and have built in flexibility which increases the stress. Older buildings are built tougher, they are strong and don't move as much in an earthquake, but strength is brittle and when they go they will likely collapse crushing the occupants.
One thing that we're not quite realising is this was a very big event. While it didn't have the devastating acceleration that the 2011 earthquake in Christchurch had (which was the highest acceleration in an earthquake ever measured at the time) it still was a huge earthquake and put a lot of stress on our structures.
This was the second biggest earthquake in NZ since Europeans have lived here, i.e. in locally recorded history. And while the epicenter was quite far away from Wellington most of the energy was released 100km north of that epicenter and much closer to us.
While it did have that disastrous acceleration the Christchurch earthquake only lasted ten seconds, this north Canterbury earthquake lasted something like two minutes. Something that was not widely reported is that quite a few of the buildings still standing in Christchurch shouldn't have been and even more were just a second or two away from collapsing so time is very important.
So of course it wasn't of the scale that the Earthquake that hit Christchurch that that shouldn't be a base measurement. It was a huge earthquake and very damaging in it's own but different way.