This is exactly what I think of all seismic alert systems. They are designed with a linear frame of mind, but earthquakes are exponential (Power Law). That's why these systems are always 'over-powered' when a real earthquake comes along.
Rather than have everything go to a central site, you would have to design a distributed 'instantly scalable' system. I've never seen such a system, but I have some ideas. I think most Internet people would have some ideas, as well.