在地球上,有足够的氢和氧13,8800万公里^ 3美元的水(计算)。然而,海洋包含只有十分之一的[2]。很明显,大部分的氢必须存储在其他化合物不同的水。或者,就像水在地球内部深处:[一些研究表明水在地球内部可能含有3倍水在地表附近][3]。另一方面有很多化学反应,如众所周知的(光合作用)[4]和[5](呼吸),可以把水转变成其他化合物,反之亦然。我们常常认为,地球上有一个固定数量的液态水(正负大气中被回收)。但在我看来,上述过程可以改变水量显著地质时间尺度。所以我的问题可以表示如下:* *在地质时间尺度,是什么决定了地球上液态水的数量?* *以下是两个例子的过程我思考:1。* *水库转移* *:如果删除从井里,周围的地面水库会慢慢填写。将同样的发生在地球上的海洋如果删除? Would water from the deep Earth's interior partially re-fill the oceans through volcanic eruptions? 2. **Chemical balance**: For a chemical reaction that can go both ways, if the reactants and products are in equilibrium and I remove the product compounds, more of them will be generated until a new equilibrium is reached. Would the same happen if I remove the water from Earth's surface? Will Hydrogen and Oxygen from rocks and air combine to partially replenish the oceans? _(This question was inspired by [How much water is the atmosphere losing to space?][6])_ ---------- **Calculation of the maximum possible water on Earth** The maximum amount of water you can have on Earth is limited by the available hydrogen. Now, for each gram of bulk Earth there are [260 $\mu\text{g}$ of hydrogen][1] and plenty of Oxygen. Given that the [Earth's mass is $5.972 \times 10^{27}$][7], and 260 $\mu\text{g/g}$ correspond to Hydrogen, that would total $1.552 \times 10^{24}$ g of Hydrogen, that at a [molar mass of 1.007 g/mol][8], corresponds to $1.540 \times 10^{24}$ mol, enough to make $7.703 \times 10^{23}$ mol of water (as two atoms of hydrogen are required in a molecule of water). And since water has a molecular mass of [18.0152 g/mol][9], such an amount of water would weigh $1.3877\times 10^{25}$ grams. Finally, assuming a density of 1 $\text{g/cm}^3$ we get a total of $1.3877\times 10^{25}$ $\text{cm}^3$ or $13,877,025,731\, \text{km}^3$; that **corresponds to 10.01 times the amount of water near Earth's surface** (including oceans, lakes, rivers, ground water, etc.) and that is estimated to add up to [1,386,000,000 $\text{km}^3$][2]. [1]: https://web.archive.org/web/20110928074153/http://quake.mit.edu/hilstgroup/CoreMantle/EarthCompo.pdf [2]: https://en.wikipedia.org/wiki/Water_distribution_on_Earth [3]: https://www.theguardian.com/science/2014/jun/13/earth-may-have-underground-ocean-three-times-that-on-surface [4]: https://en.wikipedia.org/wiki/Photosynthesis [5]: https://en.wikipedia.org/wiki/Cellular_respiration [6]: //www.hoelymoley.com/q/9488/11908 [7]: https://en.wikipedia.org/wiki/Earth [8]: http://ciaaw.org/hydrogen.htm [9]: https://en.wikipedia.org/wiki/Properties_of_water