Volume of Water in the Oceans & Seas

Of course someone has.

Approximately 1385 million cubic kilometres of water are available on earth. 97,5% of the water is salt water that can be found mainly in oceans. Only 2,5% is freshwater that can be used by plants, animals and humans. However, nearly 90% of this freshwater is not readily available, because it is centred in icecaps of the Antarctic. Only 0.26% of the water on this world is available for humans and other organisms, this is about 93.000 cubic kilometres. Only 0.014% of this water can be used for drinking water production, as most of it is stored in clouds or in the ground.

- http://www.lenntech.com/specific-questions-water-quantities.htm

Dear bhankiii,

Thanks a lot for the information you provided.

Don't thank me, thank the fine folks at google.

It is possible to render sea water fit for drinking by removing the salt. Often it is uneconomic in comparison with ground- and surface-water abstraction, which is why it is uncommon onshore. Some island communities and most ships and offshore platforms have some form of drinking water production unit that use seawater as the feed.

Thank you bhankiii:

It is very valuable information.

nice, informative post!

Yes, there are many other factors that affect rising water levels,

There is the fact that the planet is made up of large plates that are moving. Some land is sinking while other areas are rising.

There are volcanoes adding mass to the ocean bottom

There is erosion continuously adding silt to the ocean bottom

There is the remainder of the last ice age still melting, (Glaciers etc)

Last but not least, there is the fact that many large cities dump thousands of cubic meters of garbage daily into the ocean.

There are also issues with the ocean currents which can cause the amount of sea ice to increase or decrease, even in the absence of other causes.

Can we also add the volume of displacement by all sea crafts launched into our ocean waters for that matter? And also some man made developments by reclamation of some areas?

And subtract the water injected into underground reservoirs so as to increase the output of primary fuel liquids and gases?

And add the water introduced to the atmosphere as vapour from combustion of those fuels when it falls as rain?

I took a leak in the bay last week. Is Tahiti underwater?

I for one, believe that the intention of this forum is for us to share our sensible ideas, knowledge, experiences and serious thoughts about any subject being discussed. We should be mature enough to present ourselves as rational being and importantly as professionals.

However, water from melting icebergs do not add to the rising oceans as they already displace their volume while floating.

The solids washed in by the river systems should be part of any equation. I wonder how much that contributes.

Hey Techno,

We should build a time machine and go back and find Al Gore's, Cave Man ancestor so we can ask him who / what caused the global warming (high C02 levels) that caused the last ice age.

Don't forget to factor in animal waste and vegitation washed off shore!

It sounds like you're inferring that CO₂ was up during the last ice age and that somehow disproves the current theory of global warming.

The carbon dioxide content of the atmosphere for the last 4 glacial cycles is known from drilling into the ice in Antarctica, where ancient air has been trapped and now can be extracted. These results show that carbon dioxide follows the change in sea level rather closely: when carbon dioxide increases, sea level rises and vice versa. A similar relationship is seen for methane. And the last ice age was a period of low sea levels, thus low CO₂ concentrations.

BTW - the most current science points to the 40,000 year cycle of the earth's tilt, coupled with a CO₂ feedback mechanism as creating the cold / warm cycles of the earth.

"Last but not least, there is the fact that many large cities dump thousands of cubic meters of garbage daily into the ocean."

The actual density or average specific volume would occupy less volume.

Mere "Drops in the Bucket" as it were!

Good subject in this forum. I live in a Caribbean Island with a Bluff (Limestone coral) running through the center and rises to a height of 140 feet. All along the lower edge there is evidence that sea water was washing up and eroding this bluff. However, there is no indication that the water level was reseeding over time. There is a significant drop in sea level which must have occurred all of a sudden, although not in the lifetime of man. What caused this drop in sea level or rise in land?. My theory is that it happened when the Golf of Mexico was created. A very large crater, now filled with water must have taken away the water level. What do you think?

It's hard to say without knowing more about the geology of your area. But it's likely either

1) Volcanic uplift of your island, or

2) Higher seas in the distant past - before the last ice age.