The expansion of the earth's surface is demonstrated by what u. s. state that is believed to be increasing by 1.2 "nanostrains" per year?

The correct answer is - New Mexico.

The state of New Mexico is increasing in size every year and this is due to the geological activity in this part of the United States. New Mexico is actually very close to the part that's moving away from the United States's mainland, which can be easily seen be the ever growing fault. While for now this means that the land mass of this state is increasing, relatively soon (geologically speaking) the newly ''gained'' land mass will be covered with water from the ocean, because it will be able to penetrate into the ever growing fault eventually.