The testimony of Jesus Christ establishes that there's a great gulf of open space inside the Earth. It's described in the passage known as the parable of the rich man and Lazarus (Luke 16:19-31).
Biblical Seismology
Biblical Gravitation and the Cause of Noah’s Flood
A problem in creationism is: what caused the breakup of Pangaea and the formation of tectonic plates? Was it the waters of Noah's flood or an extra-terrestrial impact? We say neither.
A Great Gulf
We're at a great advantage over the spaghetti theologians because we've deduced how the passage from Luke resolves with a physical reality. We don't regard any part of this parable as being metaphorical or allegorical.
August 31st
After Noah's flood the region in the interior of the Earth, formerly occupied by the great deep (tehom), is now a great gulf or mega chasm of open space that Jesus spoke of in Luke 16:26 (sheol).