Manhattan is built on a swamp, iirc. It was not inhabited by the "Native Americans", prior to Whitey showing up. I've heard the alternative story, that it's base is granite, etc. So I am not sure. But if it is indeed somewhat unsound, a Richter >5 would probably slide the buildings right off the island into the Hudson. And then the wave would take out most of New Jersey and/or Long Island.
This is true.
Manhattan is built on a swamp, iirc. It was not inhabited by the "Native Americans", prior to Whitey showing up. I've heard the alternative story, that it's base is granite, etc. So I am not sure. But if it is indeed somewhat unsound, a Richter >5 would probably slide the buildings right off the island into the Hudson. And then the wave would take out most of New Jersey and/or Long Island.