Undoubtedly, most of this shrinkage occurred during and soon after the flood, as the mantle lost twice the volume that the dense core gained.
Among the many crustal features they felt this would explain were ocean trenches, tablemounts, and the dropping of the Pacific basin as one huge block. Most of those geologists believed that a molten earth shrunk as it cooled over millions of years. However, because they could not provide convincing details, their idea has fallen into disfavor.
What caused the shrinkage? The rising Atlantic floor would have produced the greatest movement at the center of the earth, because, geometrically, large movements near the center of a circle or sphere are needed to adjust for smaller movements near the broader circumference. As the Atlantic side of the inner earth rose, the Pacific side of the inner earth had to collapse onto the magma forming and shrinking near the center of the earth. This runaway subsidence, melting, and shrinkage would have fractured and distorted much of the region on the Pacific side of the earth—especially the Pacific crust.
Gravity always tries to make the earth more compact (or spherical). If you suddenly removed a bucket of water from a swimming pool (or even a 10-mile-thick layer of rock lying above what is now the Atlantic floor), gravity would tend to smooth out the irregularity. Because massive volumes of rock inside the earth do not flow as fast as water in a swimming pool, mass deficiencies, which we might think of as slight partial vacuums, still exist under trenches. Today, especially at low tide (when the water’s pressure on the ocean floor is a minimum), mantle material flows in very slightly under trenches to reduce these “partial vacuums.” This stretches the crust above, produces extensional earthquakes near trenches, shifts plates toward trenches, and makes the earth measurably rounder.
The mean radius of the earth has shrunk about 100 miles since before the flood. The earth is still shrinking, but at a much slower rate." by Dr. Walt Brown
For we know that the whole creation groaneth
and travaileth in pain together
until now.
Romans 8:22
