Its called Plate Tectonics. This is the overall mechanism for the drifiting of plates over the Earth's rust. Plates are subducted under other plates (eg along the Aleutian islands - hence a string of active volcanoes). Should the subduction process be delayed, there may well be a swelling which may impact on the earth's diameter (slightly).

So yes, the Earth may have gotten bigger since April.

Global warming could also play a role - expansion with heat......