Just to bump dmattox's question, because I'd like to know more.

Quote

I'm not sure how freezing would be a problem for the GES?

My understanding is that the conductivity of soil/clay/earth depends upon the ionic conduction, where ionized atoms physically _move_, rather than metallic conductivity. If the ground freezes, then the conductivity can drop in much the same way as a GES in soil that becomes very dry. At least that is my weak understanding. I'd love to learn more on this topic.

-Jon