We're not the exact experts to answer that with a clear answer, but I can tell you that there are regulations and requirements for the industry to monitor their fracturing process. For example, they have to have sensors close by to the hole to monitor how large a motion in the ground is created by the fracturing of the rock, and they can tell how far the fractures extend. So we have—not us, but the companies and the regulators actually have this—direct evidence from them of how much ground movement is taking place.
As one of the witnesses said earlier, I think the fractures end up being the thickness of a piece of paper and they can extend over maybe 100 metres. We're talking about things that are under two kilometres of rock, which is a considerable amount of weight and pressure and everything else.
I'm probably answering the question for him.