What temps are more important?

[Vengeance]

The surface temp on the top of the substrate, the temps when you bury half way down into the substrate or the temps directly at the bottom of the tank?

I'm finding that they vary quite a bit, on top the temps are sitting quite nicely at 90 - 92 but if you bury down a little bit the jump a bit to about 91 - 95, which isn't too bad, but if you get all the way to the bottom of the tank, which I have covered with newspaper, the temps skyrocket too between 95 - 100. It's only in the spot right at the basking area but I was curious as to which temps I should be most concerned with because obviously I'm never going to be able to get all 3 the same. Any suggestions? I am useing newspapaer to cover the bottom of the tank then I have Exo Terra's Jungle Earth as substrate on top of the newspaper with about a 1/2 inch layer of the substrate.