Similarly , Professor Robert T. Hill explained at that time that " the rocks are being folded , fractured and otherwise broken or deformed by the great shrinking and settling of the earth 's crust as a whole . The contraction of the earth 's sphere is the physical shrinkage of age that is measured in aeons instead of years . The prehistoric convulsions of the earth before man inhabited this planet were terrific , almost inconceivable . " There " was no doubt that earthquakes are diminishing . " The displacement of the 1906 San Francisco earthquake was only a few feet , while prehistoric earthquakes made fissures and slides of 20,000 feet
1906 San Francisco earthquake
1906 San Francisco earthquake
Geophysical global cooling