Douglas Harper's Etymology Dictionary
Usage examples of "sea-floor".
Dome today, his excursion through the processing plant outside the Dome on the sea-floor, would be vastly romantic and exciting.
The sea-floor here was evidently a bit lower than in the phase world, or mushier because of the sediment.
Only when the evidence of sea-floor spreading became undeniable did geologists begin to accept the ideas of plate tectonics, which today underpin almost all serious geomorphological work.