If salt continues to be deposited in the ocean but never leaves, will the oceans eventually become more salty?

Answer 1

Over geologic time the salt is sometimes removed from the ocean leading to a long-term equilibrium. It is believed likely that over Earth's history the oceans have increased in salinity, and one form of evidence of this is that most terrestrial animals have lower concentrations of salt than the ocean, but this is a very distant connection. Over the short term there may be variations in climate that are leading to reports of increased salinity in tropical regions, while higher latitudes are showing decreased salinity. This type of variability may only be on the scale of hundreds of years however.
http://www.whoi.edu/institutes/occi/viewArticle.do?id=897
http://www.public.hq.nasa.gov/oceans/physical/SSS.html

For example, the Gulf of Mexico has extensive salt deposits beneath the sea floor that were deposited there during the Jurassic. Under the Mediterranean there are extensive deposits of salt that are several kilometers thick. This was deposited about 6 million years ago during what is called the Messinian Salinity Crisis, when much of the Mediterranean evaporated.
http://www.messinianonline.it/

So even though in the short term it may seem that the ocean is getting more salty, there are geologic processes that operate very slowly that tend to stabilize the salt content of the oceans over time.

Answer 2

Deposited from where?

New salt is not created, just recirculated. Most of the salt we use, for example, on our food, is either extraced from the sea, or mined from deposits left from ancient, dried sea beds. Over vast millions of years, the Earth's surface, itself is recirculated as the continental plates grind into on another and new surfaces arise from the ocean's depths.

The oceans have a better chance of becoming more filthy from our wastes and carless spilling of contaminants into our waters than becoming more salty.

Answer 3

Under those conditions, yes, because you've designed it that way. However, in real life, not much more salt gets into the oceans, and salt gets removed through various means too, so it's not really getting saltier (and with global warming melting the polar ice, it'll actually get more dilute as more fresh water gets dumped in)

Answer 4

Salt, along with water and sediments, are recycled at subduction zones, where oceanic crust is thrust under continental crust. It then becomes incorporated with molten rock to form new crust, mostly in the form of basaltic lava flows.

Answer 5

^
Ditto.

IIRC, evidence suggests that the salinity of Earth's oceans has changed little since the planet formed; about as much salt is removed as is deposited.