Hello welcome to the solsarin site. Inside this post, we want to learn “how to calculate percentage of water in pacific ocean.”
What percent of the ocean’s water is salt?
Question Date: 2004-05-06
The ocean is about 3% salt. This varies a bit though, depending on where you measure it. Near where rivers reach the ocean, the salt content (salinity) will be lower. In fact, because salt water is more dense than fresh water, the river’s water will actually “float” on top of the ocean water until it is mixed together. So if you took a reading near the surface of the ocean where a river flowed in, the salinity would be lower than that near the bottom.
Evaporation takes away water, but leaves behind salt, so in places where there is a lot of evaporation, the surface water may be saltier. Where do you think the saltiest water might be? You might want to look in the ScienceLine archives for my answer to a question about salinity in tidepools.
What a great question!
Here’s how you’d find your answer:
Filter some seawater to remove all the tiny animals and bacteria swimming around in it, fill a plastic container with seawater, weigh the container and seawater, wait for the water to evaporate and then re-weigh the container and the salt left behind.
You can then calculate the percentage of seawater that is salt by weight. You’d need a precise scientific scale(your bathroom scale won’t work) because only a small fraction of the total weight of seawater is salt — about 3.47% on average.
Oceanographers call this percentage “salinity”, as in: “Seawater has a salinity of 3.47% on average.” Because it’s so small, oceanographers actually measure salinity in parts per thousand instead of parts per hundred (“per mil” instead of “per cent”), so the average salinity of the ocean is 34.7 parts per mil.
Some oceanographers dedicate their life to measuring very small changes in salinity, since this can affect large-scale ocean circulation patterns and can also give valuable information about changes in rainfall and storm patterns. In fact, small changes in salinity are what first alerted scientists that global warming has already caused large-scale changes in the Pacific and Atlantic Oceans.
Of these three bodies of water, how do you think they rank in terms of salinity, from most to least? What do you think makes these differences?
a) Atlantic Ocean
c) Pacific Ocean
b) The salinity of the Mediterranean is about 38 parts per mil.
a) The Atlantic Ocean is about 34.90 parts per mil on average.
c) The Pacific Ocean is about 34.62 parts per mil on average.
You mean the ocean’s salinity? A quick Google search came up with the salinity of the ocean being about 35 parts per thousand, or about 3.5%.
In any case, I can suggest an easy way to find out. Get a cup or a bowl or something and weigh it. Then go down to the beach and fill it with water. Bring it back and weigh it again. The difference in weights is the weight of the sea water.
Now, put your bowl out in the sun and let it dry. When all of the water has dried up, weigh it again. The difference between the bowl’s original weight and its weight now is the salt. You now have the weight of the salt and the weight of the water, so dividing the amount of salt by the amount of water will give you the weight ratio of salt to water in the ocean.
Sea water varies in its salt content from place to place. For example, there is a very low salt concentration in areas where a large river flows in to the ocean, due to high mixing with freshwater. However, in the open ocean away from land the salt content (or salinity) of the seawater tends to range between 30 and 35 ppt (parts per thousand). This is equivalent to 3.0 to 3.5 % (or parts per hundred). In hot areas where there is a lot of evaporation the number tends to be higher, whereas in areas that receive a lot of water input (such as from rain) the number will be lower.
Quantities of Water
We have an accurate idea of a litre of water, but do you know how much water there is in a cubic meter of air, or the quantity of liquid in a lake or an ocean? Do you know how much water is present when the Rhone floods the Camargue, or the flood required to create Valle Marineris on Mars? Do you know what quantity of water is ejected by a comet or is present in a cubic light year of interstellar matter?
And here is another task for you!
Try and make an original contribution associating volumes of water on Earth and volumes of water in Space! Explain this to your friends and see their reactions.
Water covers 70% of the Earth’s surface, but 97% of it has too high a salt content (salinity) to be drunk by living beings or used in agriculture.
Fresh water thus only represents 3% of the total quantity of water. Some 70% of this is trapped in the polar ice-caps. Rivers, lakes and marshes only represent 1% of the total water on Earth. The remainder is underground water.
Sea water and ice represent 99.35% of all water on the planet Earth. The remainder is underground water, and that in streams, rivers, lakes, and the atmosphere.
Some 60% of rainwater evaporates and forms clouds; 25% penetrates the soil, and 15% flows into rivers and lakes.
The Earth’s atmosphere contains 13,000 million tonnes of water. This is equal to a layer of water 2.5 cm deep, covering the entire surface of the Earth.
Now some numbers about the water on the Earth. First, here is how much water there is in the Earth’s oceans:
The oceans cover 71% of the Earth’s surface.
If the polar ice-caps in the Arctic and Antarctic melted completely, the average level of the oceans would rise by approximately 80 metres.
How much water flows in the rivers on Earth?. Here are some examples:
But the rivers also carry other things than water. As an example of the great pollution, here are a few numbers about one of the big rivers in Europe: Each year the river Rhone discharges between 2000 and 5000 tonnes of ammonia, 2000 and 13000 tonnes of chlorides, 300 to 700 tonnes of arsenic into the Mediterranean in addition to lesser quantities of copper, iron, titanium, cadmium,… Don’t you think that this is a great pity?
And here we go again:
Human beings are 75% water. Try to calculate what volume of water is contained in the 6 billion inhabitants on the planet Earth. Are you amazed?
Try to calculate some other numbers and make other comparisons. You may send in your results to Sea & Space (address on the top page).
We use a lot of water for our daily needs. Here are the quantities of water required for domestic use (mean values for a European citizen; in some countries the quatities are less because of stricter regulations):
Now try to answer these questions:
If each person living on the planet Earth took one shower every day, how much water would be used in one year?
Compare this with… (your choice!).
The Pacific Ocean is the largest and deepest of Earth’s oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south and is bounded by the continents of Asia and Australia in the west and the Americas in the east.
At 165,250,000 square kilometers (63,800,000 square miles) in the area (as defined with a southern Antarctic border), this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth’s water surface and about 32% of its total surface area, making it larger than all of Earth’s land area combined (148,000,000 square kilometers). The centers of both the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean. Ocean circulation (caused by the Coriolis effect) subdivides it into two largely independent volumes of water, which meet at the equator: the North(ern) Pacific Ocean and South(ern) Pacific Ocean. The Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific.
Its mean depth is 4,000 meters (13,000 feet). Challenger Deep in the Mariana Trench, located in the western north Pacific, is the deepest point in the world, reaching a depth of 10,928 meters (35,853 feet). The Pacific also contains the deepest point in the Southern Hemisphere, the Horizon Deep in the Tonga Trench, at 10,823 meters (35,509 feet). The third deepest point on Earth, the Sirena Deep, is also located in the Mariana Trench.
The western Pacific has many major marginal seas, including the South China Sea, the East China Sea, the Sea of Japan, the Sea of Okhotsk, the Philippine Sea, the Coral Sea, and the Tasman Sea.