It appears from the amount of subduction and upthrust around the world that the Earth's circumference has changed. It's an arcane phenomenon called circumferential shortening.
Circumferential Shortening
Uplift in Appalachian Geosyncline
"Uplift in Appalachian geosyncline" took place when the tectonic plates formed in the time of Peleg. This was 101 years after Noah's flood.