A couple of things that we need to bear in mind when we talk about an earthquake like this:
if the terrain were rocky like in Chile, the shaking is not that intense.
But when the terrain is sandy, and that's the case of Christchurch, you know, the ground shakes violently because it is softer.
It's like Haiti.
And in this case, you know, you say,
"6.3 and all this damage? What's going on?"
Well, we need to take into account depth, and it's only five kilometers deep.
We're talking about the 6.3.
So this graphic illustrates what happens when the earthquake is shallow like the one in New Zealand today.
Then we see the shaking more severely on the ground.
That's why the 6.3 doesn't seem to be that intense, but when we take into account the depth, it has been.
And also, and this is perhaps more importantly,
is that New Zealand is right in between the Australian Plate and the Pacific Plate,
so that's when the ground shakes to accommodate.
So when we have an earthquake, there's movement of these plates.
And now we may see aftershocks for months until things go back to sort of settling down again.
So don't be panicking in case [if] you feel some more shaking on the ground; [it] should be lower than what we have seen so far.
And finally, the 7.1 on the fourth of September was inside,
not on a sandy foundation -- [a] more rocky area.
That's why the shaking wasn't that violent.
So we need to entertain all these aspects.
And remember there are going to be more aftershocks for months now
until everything goes back to its normal position.