If it were breaking off, it would be incredibly slow. Like several inches a year kind of slow. It would take many millions of years, thousands at best if it could do 10 feet a year, which is impossible, tectonic plates don't move that fast. So far, no movement has really been found. You have nothing to worry about. I have a science teacher who says that, but she also says we are ruining our environment and other such liberal propaganda. The media companies choose stories to scare people, otherwise almost nobody would watch.