Molting tree?

It would appear that the really big sycamore in our back yard is molting? Um. Help?

Our yard with tree bark all over

Our yard with tree bark all over

This is one piece of bark

This is one piece of bark

UPDATE: I’ve been informed by people more knowledgeable than I that sycamore trees do this on a regular basis. In fact, since this event, we’ve had several more barkfalls, probably exacerbated by the drought this summer.