As I recall from an upper division class in earthquakes, the P and S waves produced by an earthquake allow for a “quake-o-gram” of the internal structure of the earth’s core, mantle, and crust. It is not conjecture as to what the interior architecture of the earth resembles, we have used the P-S waves to draw the size and relationship of the earths internal layers, and based on that picture, can exactly plot where future quakes occur on a map based on this internal picture and P-S wave earthquake signatures.
Hence, in light of this internal picture, I cannot envision the ability to measure quakes as we do, and have a hollow earth.
That would not fit the P-S wave measurements.
What do you think?