text:  you often get little shifts in the crust, and you get quakes that are considerably smaller than the energy of the blast itself. And this has caught my attention for some time, but I don't see anything to it, although that very same Mexican quake I just talked about, that happened to be the day of one of the largest blasts they ever did underground north of Las Vegas, the Frenchman's Flat. And when I saw that, I said, uh-oh, and then I looked carefully at the times.