I'm trying to remember the name of a book read many years ago. It took place in the US. A mountain of asphalt had been created to control weather, there was a major earthquake looming and a team of people trying to save the world. My guess is that I read the book around 2000. Also, I think the country had been divided into sections by race.
It might be O-Zone by Paul Theroux, from 1986.
It's been a while since I read it, and I don't remember a world-saving angle, but the rest all fits.
From this review:
It is an America of Us and Them.
(...) a powerful technocrat named Hardy. Hardy builds huge asphalt mountains in remote areas. Ostensibly, through a heat convection process, they serve to make rain.
Outside the enclaves is wilderness. Impoverished bands of Aliens roam throughout; some of whom are predatory and violent, while others simply scavenge and hunt. (...) A great part of the Southeast, around the Ozarks, has been contaminated by massive leaks from nuclear waste dumps. The O-Zone is sealed off (...)