Distribution of Water on the Earth

This has come up a couple of times recently, so I thought I’d summarize the information here.

The distribution of water on Earth in cubic kilometers

Salt water: 1,318,062,462
Glaciers: 28,005,430
Groundwater: 12,270,210
Lakes: 106,396
Swamps: 13,452
Rivers: 2,446
Vapor: 13,000
Biological: 1,120

(Biological means like your spit and guts and all the juicy parts of worms and tree saps and water in bacteria and stuff.)


USGS

Wikipedia

What happens if all that glacial ice melts and ends up in the ocean?

Play with this for a while to get an idea. The maximum rise in sea level in that model is probably not the maximum if all the ice melted, but all the ice won’t melt.

Maybe .

Comments

  1. #1 NewEnglandBob
    August 4, 2009

    Rut-Roh, global warming could cause melting then we are in deep, watery trouble.

  2. #2 Greg Laden
    August 4, 2009

    A total meltdown of the glacial ice would increase the amount of water in the oceans by about 2 percent. (But there are complications)

  3. #3 Nathan Myers
    August 4, 2009

    Of course nobody has even a faint idea what the cloud cover will do at the higher temperatures and C02 levels. We might end up in a global ice age after all, despite all. The global thermonuclear war likely to occur once the ice age starts might fend it off, or accelerate it. The survivors won’t even know if it did, either way.

  4. #4 Nathan Myers
    August 4, 2009

    Incidentally, I’m astonished at the precision. Do we really know the oceans’ volume to ten significant figures? I’m almost equally impressed at knowing swamps’ volume to five figures. Who knows what’s under there?

  5. #5 jimspice
    August 5, 2009

    So if you juiced every living thing on earth, you would have a cube 10.4 K on a side? But there would be no one left to measure it?

  6. #6 Greg Laden
    August 5, 2009

    Nathan: As far as swamps and groundwater go, there is, of course a whole science dedicated to that and although it is harder to measure, I’m sure we essentially “know it” even if we (well, actually, you) don’t know how other people measure it!

    As to the precision, there is no particular reason why we don’t have the precision indicated here, but I’ve not assessed that or made adjustments in these numbers. But do remember that significant digits is a buggaboo (sp?) If the measurements were made in cubic miles, the precision would go up with the same signficant digits. If the measurements were made in cubic centimeters the precision would go down. This is cubic kilometers. Cubic kilometers seemed like the right unit to use, but they are kind of small for planetary geology, so I would take the precision on the fresh water values with a grain of salt.

    But only a grain, or it will become salt water.

    If you go to the USGS source, there will be a reference to the source, where the method of estimating is probably given.

  7. #7 Nathan Myers
    August 5, 2009

    If people wouldn’t strip off error bars, they wouldn’t have to keep answering questions like this.

  8. #8 Mark P
    August 5, 2009

    Well, two percent isn’t much, but, unfortunately, the place it will be most obvious is in shallow water and lowlands. Where we like to live.

  9. #9 jj
    August 5, 2009

    Well, two percent isn’t much, but, unfortunately, the place it will be most obvious is in shallow water and lowlands

    Glacial Ice melt is NOT major concern regarding sea level rise due to global warming. It’s the expansion of sea water volume at higher temps. Or at leased that’s what I’ve heard via lectures.

  10. #10 Nathan Myers
    August 6, 2009

    Greg: Measurement precision doesn’t change when you change units, it just moves the decimal point around.

  11. #11 greg laden
    August 6, 2009

    Nathan: Well, that’s what I meant. If you look at those numbers, one has no a priori reason to question precision, but given what is being measured, seeing apparently significant digits as they are, one might suspect. But if we change to smaller units, and retained the same actual precision, you would see a lot of zeros on the right side and the perception that they are over-precise would vanish, yet the numbers are exactly the same (just different units).

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