Difference between Sea Water and Fresh Water
Water covers a vast amount of space of up to 71% of the Earth’s surface. This is inspiration for the Earth’s nickname as the blue planet. All animals, plants and humans need water in different percentages to sustain life. The fresh water and sea water distribution on earth is quite irregular resulting in favor of sea water which sustains various organisms, but cannot have the positive effects that clean, fresh water has on the human body. Ocean water needs to undergo a desalination process to become drinkable. This solution has already been implemented on a larger scale in countries where fresh water resources are scarce.
Fresh water can be found in lakes, ponds, rivers, springs and groundwater in aquifers. Other sources of fresh water are precipitations like rain, mist or snow. When ice melts due to environmental changes it also forms fresh water basins. New lakes emerge, but still, fresh water covers only 3% of the earth’s surface. Being the only drinkable water, it has to be used wisely to satisfy the demanding needs of the growing global population. Fresh water can be extracted from underground using special equipment, but it is recommended to have a controlled process as groundwater is vital for the survival of existing animals and plants in the extraction zone. Natural habitats should always be preserved as they are in close connection which each other and all contribute to ensure the planet’s balance. Sea water is a common name for sea and ocean water. Oceans cover a great deal of the earth’s surface: 97%. They annually receive precipitations which lead to volume increase. Glaciers floating in the Arctic Ocean which are melting due to global warming also contribute to raise the volumes of sea water available in the world.
Salt and Pollution
Sea water has a level of salinity of up to 3.8%. Some parts of the world have more salty water due to existing environmental conditions such as poor level of precipitation throughout the year, the evaporation factor or the difficulty in connecting with fresh water sources. Two famous places for their high degree of salt in the water are the Red Sea and the Dead Sea. Fresh water contains salt in a percentage of only 0.5%. Many fresh water sources around the world have been contaminated by industrial toxins and various forms of waste. A famous example of this is the Hudson River in New York. The Riverkeepers and the NRDC have done fantastic work in regards to identifying problems with fresh water sources and working to enact legislation to correct major issues.
Density and freezing point
Sea water has an average density of 1025 g/ml due to the great level of salt it contains. Salt also determines a decrease of the freezing point to -2.6 degrees Celsius (28.4 degrees Fahrenheit). Fresh water can reach a density of 1000 g/ml. Its freezing point is of 0 degrees Celsius (32 degrees Fahrenheit).
Similarities and Differences
- Sea water covers 97% of the earth surface, while fresh water just 3% - an imbalance which makes drinkable water a precious resource.
- Sea water contains a great amount of salt up to 3.5 %, while fresh water has only a concentration of 0.5% salt.
- The increased salt level determines a higher density for sea water and a decreased freezing point, while fresh water has a lower density and a normal freezing point.
- The Riverkeepers and the NRDC are working to protect U.S. fresh water sources from continued threats of contamination.