Facts about the World's Oceans

The other night I watched a program on the National Geographic channel called "Drain the Oceans." It was an amazing show. The fact is that we really don't know a lot about the bottom of our planet's oceans. There are a lot of things we do know:

1. The oceans occupy nearly 71% of our planet's surface
2. More than 97% of all our planet's water is contained in the ocean
3. The average depth of the ocean is more than 2.5 miles
4. Less than 10% of the oceans have been explored by humans
5. Mount Everest (the highest point on the Earth's surface 5.49 miles) is more than 1 mile shorter than the Challenger Deep (the deepest point in the ocean at 6.86 miles)
6. The longest continuous mountain chain known to exist in the Universe resides in the ocean at more than 40,000 miles long
7. The Monterey Bay Submarine Canyon is deeper and larger in volume than the Grand Canyon
8. The average temperature of the oceans is 2ºC, about 39ºF
9. Water pressure at the deepest point in the ocean is more than 8 tons per square inch, the equivalent of one person trying to hold 50 jumbo jets.
10. The Gulf Stream off the Atlantic seaboard of the United States flows at a rate nearly 300 times faster than the typical flow of the Amazon river, the world's largest river
11. A new form of life, based on chemical energy rather than light energy, resides in deep-sea hydrothermal vents along mid-ocean ridges
12. A swallow of seawater may contain millions of bacterial cells, hundreds of thousands of phytoplankton and tens of thousands of zooplankton
13. The blue whale, the largest animal on our planet ever (exceeding the size of the greatest dinosaurs) still lives in the ocean; it's heart is the size of a Volkswagen
14. The gray whale migrates more than 10,000 miles each year, the longest migration of any mammal
15. The Great Barrier Reef, measuring 1,243 miles, is the largest living structure on Earth. It can be seen from the Moon.
16. Over 80 per cent of people on earth will live within 60 miles of the coast.
17. Plastic waste kills up to 1 million sea birds, 100,000 sea mammals and countless fish each year. Plastic remains in our ecosystem for years harming thousands of sea creatures everyday.
18. Tropical coral reefs border the shores of 109 countries, the majority of which are among the world's least developed. Significant reef degradation has occurred in 93 countries.
19. Although coral reefs comprise less than 0.5 per cent of the ocean floor, it is estimated that more than 90 per cent of marine species are directly or indirectly dependent on them. Nearly 60 per cent of the world's remaining reefs are at significant risk of being lost in the next three decades.
20. Populations of commercially attractive large fish, such as tuna, cod, swordfish and marlin have declined by as much as 90 per cent in the past century.
21. Each year, illegal longline fishing, which involves lines up to 80 miles long, with thousands of baited hooks, kills over 300,000 seabirds, including 100,000 albatrosses.

Below are pictures I took from the TV program.  The first shows the mid-Atlantic ridge.

Scientists study the mid-Atlantic ridge in Iceland, where it splits through the country.  Below are a couple of examples of geysers that follow the ridge.

If the water was drained from the oceans, the mid-Atlantic ridge would be a long line of lava flow.

The ridge is not just linear, it is actually quite complex.

Along the ridge there are lots of black smokers. These hydrothermal vents are fissures in the planet's surface from which geothermally heated water flows upward. Hydrothermal vents are commonly found near where tectonic plates are moving apart, such as the mid-Atlantic ridge.  The first picture shows a black smoker.  The next two pictures show what they would look like if the oceans were drained.

Although scientists are still surprised how the areas around black smokers are choked with life, they have learned that the rich minerals coming from these vents chemically support the life.