Why is the sea salty but the inland lakes are not?

Answer 1

As water flows over land it picks up minute amounts of salts from the soil and rocks. This water does not pick up enough to be noticeable, and as it flows into lakes, it also flows out without appreciable evaporation. Only when the water reaches the end of its flow does it evaporate leaving the salt behind. As this continues throughout the mellennia, the salt concentration increases.

This applies to both the oceans as well as lakes without an outlet (Great Salt Lake, Dead Sea, Caspian Sea)

Answer 2

The source of river water are usually snow melt or rain, so it always starts off fresh. But minerals are also dissolved into the river water, so more minerals ultimately end up in the ocean. The ocean just accumulates the minerals and has no where to put them, so it just continues to be saturated with dissolved minerals.

Answer 3

Oceans take in water from all the rivers of the world combined. That's a lot of water carrying a lot of solutes into the ocean. These solutes include sodium, calcium, and magnesium salts, which result in the ocean's salty taste. Inland lakes, however, take in river water as well, but far less, and at a far slower rate. The lakes do contain salts as well, but not nearly enough to result in a detectable salty taste. There are some exceptions: the Dead Sea is an inland sea, but the rivers that feed it flow through a significant salt deposit, and its location in a desert means a high rate of evaporation. Both these factors contribute to its well-known saltiness.

Answer 4

When water from the mountains flow down into the ocean it collects salt along the way