Where does the water in the oceans?

Am I right to think that, since the formation of the atmosphere as we know it today, the amount of water on Earth has remained the same except for the" rejected "outside the atmosphere by astronauts?

If we took certain liberties in interpreting the issue, we could probably answer something like: "Yes, roughly." The total amount of water present on Earth (the "hydrosphere") today is essentially the same since the atmosphere is pretty much what it is today. We are talking about a period dating back a few hundred million years to have concentrations of nitrogen and oxygen, more or less comparable to those of today (78% and 21%), but in regarding the amount of water on Earth, there is good reason to believe it is less stable for much longer than that -to only a few hundred million years after the formation of the planet, which dates back to 4.5 billion-years, said the professor of geology at the University Laval François Huot.

But now, and that is what chicote, the question of our reader is phrasee so that itsuggests that the hydrosphere is a completely closed and sealed system. Which is far from being the case. In fact, only systems closed in this story are international gearthat is sent into orbit and the Space Station. Apart from slight losses with waste water,we confirms to the Canadian Space Agency, not a single drop of H2O sweat flares, theSSI or combinations of astronaut. To say everything, even the urine of astronauts isrecycled water.

Now, on the floor of the cows, the hydrosphere fluctuates constantly since the dawnof time. Of course, on the total amount of water, these variations and these exchangeswith the space is tiny to insignificance, but they have not always existed.

It was long believed that the formation of the Earth was "dry", meaning that there wasno water at the birth of our planet, or that the little bit of H2O this would havevanished by the intense heat that prevailed here down at this time. Hydrosphere, it was believed, would have happened or may have formed later, possibly by thebombardment of meteorites - some of which, "carbonaceous chondrites", maycontain up to 20% water.

Finally, include that even when she stays on Earth, water is not immune to the changes: plants and cyanobacteria have ceased to turn into sugar during photosynthesis. So from this point of view, the hydrosphere is not perfectly fixed.