So, ocean currents are formed because dense water (cold and salty) sinks.
![density of sea water density of sea water](https://schoolbag.info/chemistry/central/central.files/image2596.jpg)
When seawater freezes to form sea ice, salt is squeezed out and moves down into the water. The surface waters of the Arctic and Antarctic oceans become very cold and finally freeze. The winters in the Arctic and the Antarctic are extremely cold. However when the wind blows and the sea becomes rough, the two waters get all mixed up. This means that when rivers flow out into the sea the river freshwater floats on top of the sea water. Seawater is a little bit more dense than fresh water so it sinks beneath freshwater. Increasing the mass by adding salt increases the density. That stuff would be the salt, which makes the mass of water greater, without adding much to its volume.ĭensity = mass/volume. Salt water has more stuff in it than fresh water. (see image) Salt water is more dense than fresh water The other salts are made up of chlorine, sodium, magnesium, sulphur, calcium, and potassium. Or, put another way, one litre of seawater contains 35 grams of salt - that is approximately 6 teaspoons.Ībout 90% of sea salt is sodium chloride or table salt. That means that in a 100gm solution of salty water, there is 3.5 grams of salt. Ocean water has a salinity of about 3.5% salt. Salinity is a measure of how much salt there is in water. Watch this video demonstration that shows cold water sinking below warm water. That means that cold water will sink below warm water. Cold water is more dense than warm waterĬold water is heavier or more dense than warm water. The average surface temperature is about 17☌. The average temperature of the sea is about 2☌.
![density of sea water density of sea water](https://cdn.numerade.com/ask_previews/0e562973-f127-4fb6-b83d-d5d14aec474d_large.jpg)
For example the sea temperature around the Persian Gulf can be as warm as 36☌. The sea water around the equator can be very warm.The sea water around the Antarctic continent is always very cold.These measurements are often made with a CTD instrument, where the instrument is placed in the ocean water from a ship or a platform. You just need to measure the salinity, temperature and pressure to be able to find density. Density is usually calculated using an equation. If you wanted to measure the density of ocean water, you would have to collect a sample of sea water and bring it back to the laboratory to be measured. The density of ocean water is rarely measured directly. That is, water moves along the layers with the same density. Circulation in the depths of the ocean is horizontal. The deep ocean is layered with the densest water on bottom and the lightest water on top. So, the density of ocean water increases and increases as you go to the bottom of the ocean. Learn how temperature, salinity and pressure affect the density of seawater and how this affects the stratification and circulation of the ocean. The temperature of the ocean decreases and decreases as you go to the bottom of the ocean. So a layer of water with higher salinity can actual float on top of water with lower salinity if the layer with higher salinity is quite a bit warmer than the lower salinity layer. It moves water, heat, salt and nutrients around the world. The ocean has a complex circulation system called the Global Ocean Conveyor. Salinity, temperature and depth all affect the density of seawater. There is one catch though! Temperature has a greater effect on the density of water than salinity does. Cold water is denser than warm water, so it tends to sink. Given two layers of water with the same salinity, the warmer water will float on top of the colder water. Less dense water floats on top of more dense water. Increasing salinity also increases the density of sea water. So, the colder the water, the more dense it is. Ocean water gets more dense as temperature goes down. There are two main factors that make ocean water more or less dense than about 1027 kg/m 3: the temperature of the water and the salinity of the water. Biosphere ID: 107080 Abundances of the elements in Earths crust, sea water & sun and solar system. Biosphere ID: 108541 Approximate concentrations of protolytic materials in sea water and sediment pore water. Density of ocean water at the sea surface is about 1027 kg/m 3. Biosphere ID: 108511 Osmotic pressure of sea water. Ocean water is more dense because of the salt in it. The density of pure water is 1000 kg/m 3. A fun activity dealing with the density of salt water versus fresh water