Q. One primary objection to the Expanding Earth theory is the lack of an accepted process by which the Earth's radius could increase. How do you explain this?
A. The most widely accepted model for the formation of the Earth is the accretion of cosmic material into a planet sized body. Most people believe this happened rapidly so it was complete by about 4,000 million years ago, and the Earth has been a constant diameter since then.
Various evidence suggests that this rapid formation is much too fast. It is much more likely to be an ongoing formation were cosmic mass has been added to the Earth in a process of Continuous Mass Accretion of cosmic material.