Ocean water has a specific concentration of dissolved salts, a characteristic known as its salinity.
The concentration of salt in typical seawater is about 35 parts per thousand.
Understanding Ocean Salinity
Salinity is a measure of the amount of dissolved salts in a body of water. For the vast majority of the world's oceans, this level is quite consistent, averaging around 35 parts per thousand.
- Parts per thousand (ppt) is a common unit used to express salinity. It indicates how many grams of salt are dissolved in 1,000 grams of seawater.
- So, 35 parts per thousand means there are roughly 35 grams of dissolved salts for every 1,000 grams of ocean water.
What Does This Salinity Figure Mean?
Another way to express this concentration, as indicated by the reference, is by weight percentage.
About 3.5% of the total weight of seawater comes from these dissolved salts.
| Measure | Value | Description |
|---|---|---|
| Parts per Thousand | About 35 ppt | Grams of salt per 1000 grams of seawater |
| Percentage by Weight | About 3.5% | Percentage of seawater weight from dissolved salts |
This means that if you had 100 kilograms of ocean water, about 3.5 kilograms of that would be dissolved salts, with the remaining 96.5 kilograms being water.
Key facts about ocean water saltiness:
- The standard measure is called salinity.
- It's approximately 35 parts per thousand (ppt).
- This equates to roughly 3.5% of the weight of the water consisting of dissolved salts.
While salinity can vary slightly in different locations (like lower near river mouths or higher in very warm, enclosed seas), the figure of 35 parts per thousand is a widely used average for the open ocean.
