Estimate the total mass of the water in the earth's oceans.?

I found that the fraction of the earth's surface that is covered by oceans is roughly about 7/10 and the average depth of the oceans is roughly 3.711 km.

Now what?


Also please explain how you got that answer. Thanks!

5 Answers

  • 10 years ago
    Favorite Answer

    you have to calculate a volume. this requires calculating the surface area of the earth, taking 70% of that, and multiplying by the average depth of the ocean. Once you have that volume, it is a simple thing to multiply the volume by the density of sea water to achieve the mass (order of magnitude or ballpark figure based on your estimated area and depth values).

    In fact, given the other uncertainties in your values, you can simply use one cubic meter of water equals one metric tonne (1000 kg) and ignore the couple percent difference between fresh and salt water density because your value is only a gross estimate no matter how you cut it.

    I assume you know how to calculate a surface area of a sphere, and that you can look up a value for the radius of the earth.

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  • 4 years ago

    For the best answers, search on this site

    1.) Earth's mass does not change at all with population change. People consume plants and animals, which consume CO2, water, and other plants and animals. Counting the atmosphere, ocean, etc, there is no change in total mass, only a transfer between different locations. 2.) The total biomass (not just humans but *all* life on Earth) is estimated at 500 billion to 1 trillion toones (5 to 10 * 10^14 kg), whereas the mass of the Earth itself is about 6 * 10^24 kg. That means the Earth itself masses 10 billion times as much as the total biomass. The biomass is strictly limited by the availability of carbon... way lass than 1% of the crustal mass, and even less if you count the total mass of Earth. 3.) If you *did* find some way of increasing Earth's mass significantly, this would increase the attraction. Since "attraction" is just an informal word for force. This would increase the force between the Earth and Sun. But if you magically added mass to the Earth that was hurtling along around the Sun, the momentum and angular momentum would also increase, so it would not change the Earh's orbit (unless you increased the mass by, say, ploughing a bunch of big chondritic asteroids into the Earth, to boost the amount of carbon for the life that would form after the Earth cooled again from incandescence).

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  • 4 years ago

    Remember, all matter and energy on earth is recycled. Living things usually do not acquire mass from outer space. But there is some addition of mass from asteroid and cometary impacts. So over time he mass of the earth seems to be increasing a bit. But that has no relation to how many living things, including human beings, there are at any one time. There is also loss of some atmosphere over time. One could argue the case if the increase in mass from impacts were known. The mass of the sun has been calculated, as has its loss of mass via mass ejection and continuous radiation from nuclear reactions. Whether the mass is in the form of living things or non-living things makes no difference in calculating the gravitational relationship between the two objects. No matter what our population size, it is part of the mass of the earth when making these sort of calculations. The earth does not increase in mass as material is cycled through organisms. It all comes from the same place except for the addition via impacts. You can use the video training at the first three links below to organize and improve your knowledge and understanding of basic science. I suggest it because you were apparently unaware that mass is not added do the earth system by addition organisms being born. The videos are designed to train teachers who have no background in science or science education and available online at no charge. There are other more technical treatments of astrophysics topics at other links below.

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  • Anonymous
    10 years ago

    The total mass of all Oceans is 1.384 × 1021 kg.

    Source(s): MSc
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  • 10 years ago

    I guess 7.61x10^23 kg? =]

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