You may have surely heard about oceans! Do you know what oceans are? What do they have in them? How much area do they cover on Earth? All these topics would be covered in this article. So, stay tuned and get ready to know more about Oceans!
What is Oceans?
Essentially, an ocean is a water body containing salty water. Oceans cover approximately 71% of the Earth’s surface. Do you know that the blue colour of Earth is just because of the water! A major portion of the water is contained in the oceans. Thus, when viewed from space, the dominance of oceans is visible.
97% of the total water on Earth is in the ocean. This is the reason Oceans determine weather, temperature, food supply and life on Earth. A strange fact is that the oceans remain a mystery for mankind as more than 80% of the ocean floor hasn’t been mapped or explored by us. In other words, humans have explored a much greater percentage of land on the moon and Mars than the ocean floor.
The Oceans on Earth hold nearly 1.34 billion cubic kilometres of water and the water contains about 3.5% of salt dissolved in it. They also have rich stores of chlorine, magnesium and calcium. The oceans absorb the sun’s heat, transfer it to the atmosphere and distribute it across the world. This has a great impact on global weather patterns and regulates the temperatures on land.
Is Ocean water drinkable?
Ocean water contains salt. When humans consume this water, they are essentially taking in water along with salt. Humans can safely ingest small quantities of salt, the amount of salt in ocean water is much more than the human capacity. Additionally, our kidneys produce urine that is less salty than ocean water. To get rid of this excess salt, you would have to urinate more thus making dehydration, a problem for you. Thus, ocean water or seawater is not fit for our consumption.
Oceans are very deep. To simplify, the tallest mountain in the world, Mt Everest measuring 8,848.8 metres if kept inside the oceans would not even reach the surface at the deepest point. Mariana Trench is the deepest point in the oceans followed by Philippine Trench. While the Atlantic Ocean is quite shallow with an average depth of 3720 metres. This is because large parts of the seafloor are made up of continental shelves.
Different oceans on Earth
The Earth is covered by seven continents and five major oceans. But, there is only one large the World Ocean, a large water body surrounding the continents. However, it has been divided into five major oceans based on their geographical locations. These are Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean and the Arctic Ocean.
1. Pacific Ocean
The largest and deepest ocean, the Pacific Ocean spans across 60 million square miles. It goes from California to China and can be several thousand feet in depth. All the Earth’s landmasses could be put all together in the Pacific Ocean, then also it would be larger. Despite its name, it is one of the most active oceans and a large part of it, is still to be explored.
- The Ocean makes up nearly 28% of Earth’s area and stores 46% of the water surface area. The total area of it is larger than the total area of the world’s landmasses.
- It is home to some of the strongest hurricanes ever seen. The Super Typhoon Mangkhut, in 2018 hit the shores of the Philippines with winds clocking 165 miles per hour causing mass scale destructions.
- The Pacific Ocean is termed the Ring of Fire due to the earthquakes and volcanic activities around it.
- The Mariana Trench is the deepest point on Earth. It sits along the Ring of Fire, east of the Philippines. It is much deeper than Mt. Everest.
- The Pacific Ocean is of huge importance because of the major routes of exploration and transportation.
2. Atlantic Ocean
The Atlantic Ocean is the second-largest ocean with a total area of 41 million square miles. It pies an elongated, S-shaped basin extending between Europe and Africa to the east and America to the west. It gets its name from Greek mythology and means the ‘Sea of Atlas’.
- The Atlantic Ocean covers approximately 20% of Earth’s surface and nearly 29% of the water surface area.
- It has an average depth of 3300 metres and a maximum depth of 8380 metres at the Puerto Rico trench.
- The Ocean is nearly 7.5 times the size of the area of the United States.
- The Atlantic Ocean’s water is much more saline in nature than any other ocean with values over 37 parts per thousand in certain regions.
- It includes several major water bodies such as the Black Sea, Caribbean Sea, Mediterranean Sea and the North Sea.
3. Indian Ocean
The Indian Ocean gets its name from the country India and is the third-largest ocean in the world. It covers nearly one-fifth of the total ocean surface area and stretches for more than 28 million square miles.
- The Ocean has an average depth of 12,990 feet or 3,960 metres. The deepest point in the ocean is the Sunda Deep of the Java Trench, south of the Java island which is 7,450 metres deep.
- It is bounded by India, Pakistan, Iran and Bangladesh in the north, Antarctica to the south, Malay Peninsula, the Sunda Islands of Indonesia and Australia to the east and Africa and Arabian Peninsula to the west.
- The greatest width of the ocean is 1000km between Australia and the east coast of Africa.
- It is home to some of the most well-known islands like Mauritius, Sri Lanka, Madagascar and Maldives.
- The countries along the coasts of Indian Ocean are home to more than 2.7 billion people.
4. Southern Ocean
The Southern Ocean also known as the Atlantic Ocean is located completely in Southern Hemisphere and thus gets its name. It is the youngest of all oceans as it was formed when South America and Antarctica moved apart nearly 30 million years ago.
- It is the fourth largest ocean in the world and covers just 6% of the Earth’s surface. It has an overall area of around 8 million square miles.
- The average depth of the ocean is about 3200 metres or 10,700 feet. The deepest point in the Southern Ocean is more than 7000 metres deep and is called the South Sandwich Trench.
- It was created the fifth world ocean in 2000, from the southern parts of the Atlantic, Pacific and the Indian Oceans.
- The largest ocean current, the Antarctic Circumpolar Current, is 13,049 miles in length and moves towards the east.
5. Arctic Ocean
The northernmost water body of the world, the Arctic Ocean encircles the Arctic region. A major portion of the ocean is covered with ice and snow throughout the year. But this condition has been changing due to the stark increase in temperatures.
- The oceans spans 5.4 million square miles and is the smallest ocean. It is roughly 1.5 times the total area of the United States.
- The average depth of the ocean is 1205 metres and the deepest point is Fram Basin which is 4665 metres deep inside the surface.
- The Arctic Ocean gets the name from the Greek word- Arktos which comes from the constellations, the Ursa Minor and the Ursa Major.
- The ocean covers parts of eight countries – Canada, Iceland, Norway, Greenland, Sweden, Russia, Finland and the US. These countries form the Arctic Council.
- The Arctic Ocean has numerous glaciers that are storehouses of a large portion of freshwater.
- Due to several atmospheric temperature changes, the ice in the regions are melting and the region is becoming warmer.
Who lives in the oceans?
The oceans are home to millions of different species of animals and plants. Organisms ranging from tiny single-cell animals to the largest living animal, the blue whale can be found in the waters of the oceans. Fishes, octopuses, dolphins, whales and eels live in the upper layers of oceans while crabs, oysters, starfishes and snails prefer deep ocean bottoms.
Phytoplankton, small microscopic organisms that produce their food by photosynthesis are responsible for about half of the world’s oxygen production. Life in the oceans also depends on these organisms. Since only 5% of the oceans have been explored, there are no fixed estimates of the total number of species living in the oceans.
Some of the prominent animals found in the oceans are:
Some estimates suggest that the world ocean is home to nearly 20000 species of fishes. Marine fishes can be classified into five main categories, coastal fishes, deep-sea fishes, pelagic fishes, demersal fishes and coral reef fishes.
These are cold-blooded animals living in freshwater and seawater. They are slow on land and their movement is limited. Due to habitat degradation and illegal hunting, they are on the verge of extinction.
Another type of fish, sharks have been in the ocean waters for millions of years. With over 500 species of sharks, they can be seen in various sizes and shapes. They are one of the biggest predators living in the oceans.
These are birds depending on the oceans for their life. Some seabirds are penguins, bald eagle, Arctic tern, pelicans, European herring gull and Atlantic puffin. They have specialised salt glands which help them treat the salt they consume.
There are probably millions of other species living in the oceans. All organisms have different body structures and have adapted to live in and around the oceans, with a majority of them living on the ocean floor.
Significance of Oceans
The Oceans are the heart of the planets. Oceans are of utmost importance to the human race. Some of the important uses of oceans have been listed below.
- They regulate the Earth’s temperature.
- Oceans produce much more oxygen than the Amazon forests.
- Millions of species of organisms live and depend on the oceans.
- They are an important source of food.
- Oceans also act as employment providers to millions of people.
- Although the ocean water is saline, modern treatments can make it fit for consumption.
- They are sources of recreation.
What are the issues that have affected the oceans?
The oceans of the world are under serious concern due to the numerous activities. These issues are not only affecting the oceans but also marine life. Thus, conserving the oceans and stopping these activities is the need of the hour.
Every day, beaches all around the world get littered with garbage and the ocean waters take it with themselves. Garbage in rivers and streams also ends up in oceans. Several garbage islands have also been formed in oceans.
This doesn’t require any introduction. Fertilisers and pesticides regularly get flushed in oceans which harms the species living in oceans.
Overfishing has led serious reduction in the number of species of fishes in oceans.
4. Marine and oil activities
Activities such as drilling, construction have damaged and changed the marine habitat. This has led to the destruction of ocean life as well.
5. Ocean acidification
The increased levels of carbon dioxide have increased the pH levels of oceans disturbing marine life.
6. Increased temperatures
Rising temperatures have led to the melting of glaciers, increase in sea levels. This has caused an imbalance in food chains.
How can oceans be conserved?
The question arises of how oceans can be conserved. There are several things you can do to prevent the oceans from your side. Some of them are:
- Make safe, sustainable seafood choices
- Reduce energy consumptions
- Use less plastic products
- Take care of the beaches
- Purchase items that are marine life friendly
- Support organisations preventing oceans
- Create awareness about ocean safety
So that now we have learnt a lot about oceans, it’s time to test the knowledge you have gained. We are going to ask some questions below. Try and answer the questions in the comments section below.
Q1. How much water is present in the oceans?
Answer -> 97%
Q2. Is ocean water consumable?
Answer -> No, ocean water is not fit for consumption.
Q3. Name some animals living in oceans.
Answer -> fishes, turtles, sharks, seabirds and mammals
Q4. Name the largest and smallest ocean in the world.
Answer -> Largest – Pacific
Smallest – Arctic