Why is the ocean salty?
Show answer & explanation
Answer: Salt deposits dissolved over time
Salt deposits dissolved over time ✓ — Correct! For billions of years, rain has weathered rocks on land, dissolving minerals including salts. Rivers carry these dissolved minerals to the ocean. Water evaporates, but the salts stay behind, accumulating over time. Underwater volcanic activity also adds minerals. The ocean has been collecting these salts for over 3 billion years!
Sea creatures produce salt — Wrong. Sea creatures don't produce salt. In fact, marine organisms must adapt to the salty environment. Some filter salt out, others maintain salt balance. The salt comes from rock weathering and volcanic activity, not biological processes.
Evaporation concentrates salt — Wrong. Evaporation is the result, not the cause. Evaporation does concentrate salt in areas like the Dead Sea, but it doesn't explain where the salt came from originally. The salt is from weathered rocks carried to the ocean by rivers over geological time.
More Earth Science questions
- In folded Appalachians, why can one rock layer become a ridge while its neighbor becomes a valley?
- Loose material moves downhill from a fresh fault scarp, rounding it. What sets the smoothing speed?
- Why can a long active fault affect more river basins than a short one?
- Why does erosion happen faster near active faults than in areas with heavy rain?
- Why can quartz sand with beryllium-10 reveal how fast a whole river basin erodes?
- Earthquake shaking lasts seconds. How can it leave rock easier for later rivers to erode?
