Is Jerusalem located on a big fault line?
Yes. Jerusalem, along with the Jordan Valley, the Dead Sea, and the Sea of Galilee, is described as sitting right on a tremendous fault line. This is presented as historical fact, which explains the great earthquake that occurs at the midpoint of the tribulation.
Les teaches that Jerusalem, the valley of the Jordan, the Dead Sea, and the Sea of Galilee all sit right on a tremendous fault line, and he calls this historical. In the context of these verses, at the midpoint of the tribulation, the same hour as the two witnesses ascend, there is a great earthquake. Les connects that earthquake to this fault line and stresses that the tribulation is a time of the miraculous and supernatural, when God will not hide what He is doing from the whole world.