<p>Here is a very simplistic approximation:
The total volume of the oceans (no lakes, rivers, water vapor) is around $1.3\ 10^9$ cubic kilometers. The surface area of Earth is around $5\ 10^8$ square kilometers. Dividing the volume by the area, we get a depth of 2.5 kilometers. The fresh water contribution is about 3% of the volume of salt water.</p>

<p>In reality, other factors such as the fact that Earth is not spherical, density changes, and that the water will be acted upon by tidal forces and other interactions, will make the distribution uneven. </p>

CC BY-SA 3.0
2017-04-17T03:29:38.593Z
A cup of water is enough to cover a "completely flat earth"....which is a relatively meaningless answer, but answers the question. Perhaps a better question would be, "To what depth would the world's water cover a completely flat earth?", which may be the question that aretxabelata is answering.
Knob Scratcher
CC BY-SA 4.0
2018-05-06T23:52:42.413Z
@KnobScratcher I'm not so sure about that, because at some point surface tension will take over.
Spencer
CC BY-SA 4.0
2018-05-08T02:52:46.077Z
@KnobScratcher no its not, because there are not enough molecules, even at the thickness of a single molecules you can't a cup of water spread over even a continent.
John
CC BY-SA 3.0
2017-04-14T02:19:03.633Z
2017-04-14T02:19:03.633Z
arkaia
<p>Is there enough water in the oceans, ice caps, rivers and streams to cover a completely flattened earth, in proportional to land volume and water volume?</p>

CC BY-SA 3.0
2017-04-14T02:18:54.400Z
I assume when you say "a completely flat Earth" you are talking about a sphere or better a geoid in which flat means perpendicular to gravity.
arkaia
CC BY-SA 3.0
2017-04-14T16:49:05.340Z
@aretxabaleta provides an answer below, but I think a key part of the question here is "to what depth," because presumably only a few microns would do. If you ask me if there's enough peanut butter to turn a loaf of bread into sandwiches, I need to know not only the size of the loaf and the amount of peanut butter in the jar, but how thickly you think the peanut butter should cover the bread.
jeffronicus
CC BY-SA 3.0
2017-04-18T13:55:03.387Z
What do you mean by *in proportional to land volume and water volume*?
gerrit
<ocean><water><sea-level>
Is there enough water to cover the surface of a topographically normalized earth?
Greg Bikes
# Is there enough water to cover the surface of a topographically normalized earth?

(Asked by: username_0 on 2017-04-14)

Is there enough water in the oceans, ice caps, rivers and streams to cover a completely flattened earth, in proportional to land volume and water volume?

**Tags:** ocean, water, sea-level

> **Comments:**
> **username_1**: I assume when you say "a completely flat Earth" you are talking about a sphere or better a geoid in which flat means perpendicular to gravity.  
> **username_2**: @aretxabaleta provides an answer below, but I think a key part of the question here is "to what depth," because presumably only a few microns would do. If you ask me if there's enough peanut butter to turn a loaf of bread into sandwiches, I need to know not only the size of the loaf and the amount of peanut butter in the jar, but how thickly you think the peanut butter should cover the bread.  
> **username_3**: What do you mean by *in proportional to land volume and water volume*?  

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## 1 answers

### Answer by username_1 on 2017-04-14. Score: 7

Here is a very simplistic approximation:
The total volume of the oceans (no lakes, rivers, water vapor) is around $1.3\ 10^9$ cubic kilometers. The surface area of Earth is around $5\ 10^8$ square kilometers. Dividing the volume by the area, we get a depth of 2.5 kilometers. The fresh water contribution is about 3% of the volume of salt water.

In reality, other factors such as the fact that Earth is not spherical, density changes, and that the water will be acted upon by tidal forces and other interactions, will make the distribution uneven.

> **Comments:**
> **username_4**: A cup of water is enough to cover a "completely flat earth"....which is a relatively meaningless answer, but answers the question. Perhaps a better question would be, "To what depth would the world's water cover a completely flat earth?", which may be the question that aretxabelata is answering.  
> **username_5**: @username_4 I'm not so sure about that, because at some point surface tension will take over.  
> **username_6**: @username_4 no its not, because there are not enough molecules, even at the thickness of a single molecules you can't a cup of water spread over even a continent.  

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