Before land formed on the Earth,where did all the water come from which covered the Earth?

Answer 1

As the Earth coalesced from primordial gases, the land formed first - mostly partially solid crusty plates floating over the molten liquid magma of the mantle. These would have been sort of like the skin that forms on pudding as it cools.

At the time, any water on Earth was in the form of water vapour, in the atmosphere. It would have been much too hot for the water to be liquid. So it was like steam in the atmosphere as the crust cooled.

At some point, when the crust had cooled just enough, it would have reached a critical point at which the air temperature would have dropped just enough for the water vapour to actually drop to the liquid phase. (Exactly what that temperature would have been depends on what the pressure of that early atmosphere was - which is still a matter of speculation).

After the shift to that liquid phase, it would have started raining. A lot. Like millions and millions of gallons per minute kind of rain. As the rain hit the still cooling crust, it would have vaporized back into steam, moving back up into the atmosphere. This would have cooled the crust, and facilitated more water vapour dropping to liquid, and falling as rain - a continuous cycle.

So it likely would have rained constantly for a million years or more until things were cool enough that oceans could form, and the skin of the Earth's crust was cool and solid enough to remain as land. This would have been the beginning of real plate tectonics as we know them - as well as setting the stage for the conditions for life to form.

Answer 2

Mr. Perfesser and Gene are the only ones close by suggesting comet bombardment. The planet would have boiled off any water vapor during its formation (assuming there was any water present at the time) and it would have burned off all combustibles which may have theoretically produced some water. Methane formed water would require an extremely rich oxygen atmosphere and both would have had to survive through our formation. It is generally accepted that atmospheric oxygen is liberated from water. There is no evidence to suggest the Earth ever had methane oceans or an oxygen rich atmosphere ( I understand about the presence of methane hydrates but the comparable volumes makes this bulk of methane negligible). A very small percentage of Earth's water comes from volcanic outgassing.

The truth is. Nobody knows why there is water on this planet. There is a theory that the Earth was bombarded by icey comets. However, the number of comets required is much greater than any reasonable model or physical evidence suggests. The issue is not only that we have water but why we have so much water. This has never been answered and certainly was not taught in the 8th grade class as suggested.

Answer 3

The water didn't appear until after the land formed, because the surface of the earth was hot molten rock. It had to cool for a few hundred million years to form a solid crust before the oceans could form. Nobody knows for sure where the water came from. One popular theory is that it came from a lot of icy comets hitting the earth.

Answer 4

The big bang created only Hydrogen and Helium (we think). Lots and lots of this clumped together to form stars. Some stars became so massive that their gravity was so strong that fusion was able to occur and create the rest of the fundamental chemical elements e.g. carbon, oxygen, iron, silicon etc. When stars exploded, as many of them do, the material was scattered across the universe to be captured by the gravity of other stars e.g. our sun.

Once in orbit around a star these particles or elements coalesced and the earth was formed - lots of solid stuff and lots of gassy stuff all clumped together because of gravity. After that all you need is some energy to combine hydrogen and oxygen to make water. Water tends to collect together so pools and eventually oceans form.

Answer 5

The Essex & Suffolk Water company

Answer 6

Waters under the firmament and under the firmament and all that Genesis stuff, ask Phil Collins if you need to know more about Genesis.

Answer 7

a lake of pure methane with methane feeding bacteria, when earth was hit by an asteroid with some algea like bacteria on it that slowly changed methanes composition and formed water.

Answer 8

Commonly followed theory says that most of it came from comets.

Answer 9

Standpipes?

Answer 10

Read here:
http://www.globalchange.umich.edu/globalchange1/current/lectures/first_billion_years/first_billion_years.html

EDIT: here's a hint - there was land before there was water.