Subhasis Sen is the author of 'Decoding the Solar System' (2011), a retired Indian geologist. He has taken an especial interest in the geology of Gondwanaland (the southern half of Pangea) from which he developed an expanding earth theory based on global tectonics. He has used this research into earth geology to take a different approach to solar system geology, a novel approach, or projection.
He says that if you reduced the radius of the earth to two thirds of its present size all the continental fragments would slot in together – and there would be no major oceanic waters. The author goes on to say that the primordial earth, oceanless, must have received all its water from within the mantle (as suggested by Hilgenberg) which would mean the mantle was fluid or semi fluid in nature. He refers to a 1961 experiment that proved silicate rocks melt under hydrothermal and high pressure conditions.
What caused the outgassing? The earth captured the Moon and the tidal effects caused periodical bulging of the semi fluid mantle – and the oceans came into being to compensate for changes in fluidity. The tidal pull of the Moon was also responsible for cracking the crust (and so on). No catastrophism is involved in the process and no reason given for the fact the earth is currently not expanding. He is also forced to think in terms of the outer core being a void (a hollow part of the earth) as a result of loss of material in the expansion.