Why sea contains salt

Magnesium and sulfate make up another 10 percent of the total. Other ions are found in very small concentrations. The concentration of salt in seawater salinity varies with temperature, evaporation, and precipitation. Salinity is generally low at the equator and at the poles, and high at mid-latitudes. The average salinity is about 35 parts per thousand.

Stated in another way, about 3. Warmer climates may lead to more rain and melting ice in the northern hemisphere, and more evaporation in the southern hemisphere, which could change the saltiness of our seas. The saltier that water is, the more dense or heavier it becomes. Along with warmer temperatures, this could affect how water moves around in the oceans, which could affect all life on our planet — not just the creatures living in the sea. This article has been updated to reflect the fact that sodium and chloride ions separate out when dissolved in water.

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Why do I have boogies and why does my nose keep replicating them? The answer is really very simple. Salt in the ocean comes from rocks on land. Here's how it works The rain that falls on the land contains some dissolved carbon dioxide from the surrounding air. This causes the rainwater to be slightly acidic due to carbonic acid.

The rain physically erodes the rock and the acids chemically break down the rocks and carries salts and minerals along in a dissolved state as ions. The ions in the runoff are carried to the streams and rivers and then to the ocean. Many of the dissolved ions are used by organisms in the ocean and are removed from the water. Others are not used up and are left for long periods of time where their concentrations increase over time. The two ions that are present most often in seawater are chloride and sodium.

By the way, the concentration of salt in seawater salinity is about 35 parts per thousand. In other words, about 35 of 1, 3. And, just so you don't think seawater is worthless, a cubic mile of it also can contain up to 25 pounds of gold at a concentration of 0.

Before you go out and try alchemy on seawater, though, just think about how big a cubic mile is 1 cubic mile contains 1,,,, gallons! In , scientists exploring the NW Eifuku volcano near the Mariana Islands reported seeing small white chimneys emitting a cloudy white fluid near the volcano's summit, as well as masses of bubbles rising from the sediment around the chimneys.

In this picture you can see masses of minerals and carbon dioxide escaping from the earth's crust into the ocean. These vents contribute dissolved minerals to the oceans, which is one reason the oceans are salty.

Credit: NOAA. Why is the sea salty and why is the sea blue. Share facebook twitter email whatsapp. Why is the sea salty?

And why is the sea blue? Why is the sea blue? Blog Welcome to the Rockpool Horror Show Life in our rockpools is more gruesome than you might think. Read on if you dare….