71% of Planet Earth’s surface is covered by water. It’s technically 1 big Ocean, however, it is divided into 5 basins: Pacific, Atlantic, Indian, Southern & Artic. Historically there were only 4, but in 2000 The Southern Ocean became officially recognised.
With most of our planets surface being covered in water, it comes as no surprise that 94% of Earth’s living species exist within the oceans! However, on the other end of the scale, less than 5% of the Earth’s oceans have been explored.
According to the World Register of Marine Species, there are now 240,470 accepted species, but this is believed to be just a small proportion of the species that exist, with new marine life being discovered every day.
Ocean currents are continuous and directed movements of ocean water. These currents are on the ocean’s surface and in its depths, flowing both locally and globally. Winds, water density, and tides all drive ocean currents. Coastal and seafloor features influence their location, direction, and speed. Earth’s rotation results in the Coriolis Effect which also influences ocean currents. It takes approx. 1000 years for water to complete a full, continuous journey around the world via the Global ocean conveyer belt.
The tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces of the Moon and the Sun, and the rotation of the Earth.
The average depth of all oceans together is around 3,700 metres.
Naturalist divers would be interested to know that there are just over 240,000 known marine species that are included within the 28 major animal groups that live in the ocean.
For all you wreck divers out there, did you know there are approximately 3 million shipwrecks in the oceans and more artefacts than all of the world’s museums combined?!
Deep divers will be amazed to know that the deepest dive ever to take place was achieved in the Red Sea in 2014. Ahmed Gabr reached 332.35 metres – the dive lasted 15 hours!
For technical divers – The pressure at the bottom of the ocean would crush you like an ant! In the deepest part of the Mariana Trench, the water pressure is eight tons per square inch – if you got down there, you’d feel like you were holding up 50 jumbo jets!
For the warmer climate divers. You may think that the deepest parts of the ocean would be very cold, but actually most of them can reach up to 400°C. This is emitted from Hydrothermal vents where the seawater is heated by hot magma below the Earths crust.
Here are some interesting facts about each one of our Oceans.
- This is the largest of all oceans, it occupies around a third of the Earth’s surface.
- It spans from the West Coast of North & South America across to the East Coast of Asia and Australia.
- It covers more than 60 million square miles.
- Its average depth is 4,000 metres.
- It holds 12 different seas: Philippine Sea, Coral Sea, South China Sea, Tasman Sea, Bering Sea, East China Sea, Sea of Okhotsk, Sea of Japan, Yellow Sea, Celebes Sea, Sulu Sea and Sea of Chiloe.
- Its deepest part (which is officially the deepest place on Earth) is more than 11,000 metres deep. This is known as the Challenger Deep and is located in the Mariana Trench.
- It is home to The Mariana Trench – the deepest oceanic trench. Did you know more people have visited the moon than gone into the Mariana Trench?!
- It was named “Pacific” due to the calmness of the water at the time (‘pacific’ means peaceful).
- Despite its name, it can stir up some of the strongest hurricanes ever seen.
- It is known as the “Ring of Fire” because of the area of earthquake and volcanic activity around its edges.
- It is home to the world’s largest living structure – the Great Barrier Reef. Off the coast of Australia, it spans across approx. 16,155 miles.
- More than half of it is still waiting to be explored!
FUN FACT: If you could put all of Earth’s landmasses together the Pacific would still be larger.
- This is the second-largest ocean occupying approx. one-fifth of the Earth’s surface.
- It sits between the East Coast of North & South America and the West Coast of the UK & Ireland, Europe and Africa.
- It covers approx. 41 million square miles.
- Its average depth is 3,300 metres.
- Its deepest part is 8,376 metres.
- It holds 10 seas: Caribbean Sea, Mediterranean Sea, Hudson Bay, Norwegian Sea, Greenland Sea, Scotia Sea, North Sea, Baltic Sea, Irish Sea and The English Channel.
- Its most outstanding feature is the Mid-Atlantic Ridge. It is the largest underwater mountain range that extends the length of the ocean and is roughly 1,000 miles in breadth!
- The mysterious Bermuda Triangle is located here and falls between Bermuda, Puerto Rico and Florida.
- The Atlantic accounts for 25% of the worlds fishing grounds.
- It also accommodates vast amounts of oil & gas fields and sand & gravel aggregates that are all harvested in vast quantities at any given time.
FUN FACT: (Lets call this more interesting than ‘fun…’). The RMS Titanic sank after hitting an iceberg in the Atlantic’s well-known ice fields. It now lies 3,700 metres below the surface (approx. 13 nautical miles away from its last known position) off the SE coast of Nova Scotia. It was on its maiden voyage from Southampton to New York and was only 3 days away from New York – she was the largest ship of its time and had coincidently been dubbed ‘the unsinkable ship.’
- This is Earth’s third-largest ocean, covering approx. 20% of the Earth’s surface.
- It sits in the middle of East Africa, Australasia and South of India.
- Its average depth is around 3,890 metres, its deepest being 8,047 metres.
- Its Northern area is landlocked.
- It is the warmest ocean in the world.
- It holds 7 seas: the Arabian Sea, Bay of Bengal, Andaman Sea, Red, Java Sea, Persian Gulf and Sea of Zanj.
- Because of its high temperature, it’s difficult for Phytoplankton to grow in most areas. This is one of the main reasons for the limited marine life in this Ocean when compared to other oceans.
- Another reason for the limited marine life in some areas is due to its low oxygen content.
- It’s home to many tectonic plate boundaries.
- It holds many oceanic ridges and fracture zones and features many seamounts.
- It has the fewest number of trenches of any of the World’s oceans.
- It is home to the world’s biggest submerged continent – The Kerguelen Plateau.
- It is home to 40% of the World’s oil production.
FUN FACT: It is estimated that the Indian Ocean becomes approximately 20cm wider every year!
- Also known as ‘Antarctic Ocean.’
- It surrounds Antarctica and is unbroken by any other landmass.
- It is the second smallest ocean and covers only 6% of Earth’s surface.
- The average depth is approx. 3,200 metres, its deepest point is 4,800 metres.
- It has 16 seas: the Weddell Sea, King Haakon VII Sea, Lazarev Sea, Riiser-Larsen Sea, Cosmonauts Sea, Cooperation Sea, Davis Sea, Mawson Sea, Dumont D’Urville Sea, Somov Sea, Ross Sea, Amundsen Sea, Bellingshausen Sea, Drake Passage, Bransfield Strait and it’s part of Scotia Sea too.
- You will encounter many icebergs, of varying sizes, throughout the year. They can reach several metres high!
- Its average lowest temperature is -2°C, and its highest being 10°
- The most hunted living species here is the Antarctic Krill. This is mainly used for aquaculture food, fish bait, medical research and a small proportion is used for human consumption. This is causing an issue in the area as Krill is the base of the Antarctic food chain.
- Work is currently being done to implement a Marine Protected Area (MPA) in the Southern Ocean due to its pristine water, untouched habitats and amazing marine life. When in place, it will be the largest MPA in the World.
FUN FACT: The largest invertebrate found on our planet, The Giant Squid, lives in the Southern Ocean.
- It is the smallest ocean we have on Earth, covering 6.1 million square miles.
- The ocean sits in the Arctic Circle and is surrounded by Russia, Canada, Greenland, Iceland and Norway.
- It covers only 3% of Earth’s surface.
- Its average dept is 1,038 metres, its deepest being 5,450 metres.
- It holds 7 seas: Barents Sea, Kara Sea, Laptev Sea, Chukchi Sea, Beaufort Sea, Wandel Sea, Lincon Sea.
- This ocean has many deep trenches and is home to the biggest ridge – Lomonosov Ridge.
- Most of this ocean is covered in ice. The ice thickness varies throughout the year. But due to climate change & global warming, the ice melts more often than it should, then re-freezes during the colder months.
- Icebergs can be seen all year round and chunks of ice can be seen breaking away from the ice packs throughout the year.
- The temperature of the water is quite constant at around -2°
- However, in most recent years, the ocean has been experiencing some of the World’s most drastic warming from climate change. Scientists have measured dwindling ice cover and high temperatures.
FUN FACT: It is the only place you can find Walrus, Polar Bears and Narwhals.
What’s the difference between an Ocean and Sea?
Sea and Ocean are two different large bodies of water. People often use them interchangeably, but they are not the same. However, all the seas and oceans are all connected into one large body of water.
The sea refers to a body of salt water that covers most of the earth. Generally, it is a secondary body of salt water that is largely landlocked. It is often between connected to an Ocean. Seas are usually around the land, and they are greatly made up of marine life. An Ocean is much larger than a Sea and is actually a combination of seawater bodies. It is also a large body of water that exists between continents. Oceans have more depth and do not support a great variety of marine life like the Sea. There are also farther away from the land, which further reduces the possibility of aquatic life in an Ocean.
World Oceans Day
“World Oceans Day unites and rallies the world to protect and restore our shared ocean. The Conservation Action Focus is on the protection of 30% of the Earth's land and ocean by the year 2030.”
This is growing collaborative conservation around the globe with a network of leaders in 140 countries, providing resources for all to take action to restore and protect the ocean.
Sign the petition to encourage our world leaders to do something sooner rather than later
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