Well the topmost layer of the earth (aside from the atmospher) would be the crust. It is made up of tectonic plates that move in different directions. The collisons and abrasions made by these plates sliding and crashing into each other means that mountain ranges pop up like wrinkles, and continents can move around over time. This happens over millions of years.
12 am because you are 2 hours ahead.
First one is Hoover dam
Second one is too prevent floods downstream