Origins
A surface is an over-face. The word was coined in French from sur- ('above, over', from Latin super) and face ('face', from Latin faciēs). What faces you from above — the outermost layer of any object.
English borrowed the word in the 17th century, and it immediately developed a double life. The literal surface is physical: the surface of a table, the surface of the Earth. The metaphorical surface is what you see before you look deeper. 'On the surface, everything seemed normal' implies that beneath it, things were not.
This suspicion of surfaces runs through the word's relatives. Superficial — from Latin superficiālis — means staying on the surface, lacking depth. A superficial wound touches only the skin. A superficial person examines nothing below the obvious.
Figurative Development
The verb 'to surface' appeared in the 19th century as a naval term. When a submarine surfaces, it rises from the hidden depths to the visible world above. The metaphor extended naturally: information surfaces, memories surface, scandals surface — all emerging from concealment into view.
Other sur- words share the 'over' prefix: surname (the name placed over your given name), surplus (over what is needed), and surpass (to pass over someone in achievement).