|2010-11-18 13:36:12||Climate.Geology Question|
Hey, I have a climate related question for whoever may have some knowledge on it. |
What caused the initial cooling 4 billion years ago that caused the oceans to form.
The heat output of the Sun was smaller back then due to its relationship to the mean mass of its fuel, so the Earth was too hot because of the gravitational energy released by its formation.
Earth cooled because its heat source declined - it 'used up' the gravitational potential of its formation (i.e. radiated it out). Any water that hadn't been boiled off could then condense out, but I believe there was very little (as in almost zero) left.
Water most likely arrived from ice bombardment as Earth swept up nearby comets and the like.
Source: memory from a planetary sciences course I did in my masters, but a quick search finds this: http://adsabs.harvard.edu/abs/2000M&PS...35.1309M