Why Is the Ocean Salty? (It Starts on a Mountain)

Rivers are fresh. Rain is fresh. So why is the ocean salty? The answer starts on top of a mountain. In this animated explainer, we follow salt on its journey: from rain that slowly dissolves rock, to rivers that carry it to the sea, to the evaporation trap that keeps it there, plus volcanoes and hydrothermal vents pumping in even more. We also visit the Dead Sea, the Baltic Sea and the global conveyor belt that salt helps drive. ⏱️ Chapters 0:00 Why is the ocean salty? 0:31 Rain is a (very) weak acid 0:46 How rain breaks down rock 1:05 Rivers carry salt too 1:23 The evaporation trap 1:44 Why most lakes are fresh 2:10 Why it's table salt 2:39 Hydrothermal vents and volcanoes 3:06 The numbers 3:28 Is the ocean getting saltier? 3:50 Not all seas are equally salty 4:12 The Dead Sea 4:21 How salt moves the ocean 4:49 Why you can't drink seawater 5:03 You're tasting mountains Sources: NOAA and USGS. Subscribe to Terra Explained for new Earth science stories every week. #ocean #science #earthscience #education #animation