# Would there still be land if the amount of water in the oceans was doubled?

A portal to another Earth in a parallel universe is open at the bottom of the Ocean and all the water is moving to the new Earth in the form of a waterfall in the middle of the Atlantic. The form of new Earth is exactly like ours.

• Is there still land available? If yes, how much?

I'm focusing on this new Earth.

• Please specify what do you mean by land, some of them float you know... – user6760 Mar 6 '19 at 10:59
• Floating land is ok. – Malkev Mar 6 '19 at 11:10
• the icecaps would not melt and flow to the other earth. Also there are places in oceans that are deeper that atlantic. this water would also not flow through your bottle. Additionally, a bottle is not very wide, so it would take reasonable time for the water to flow through. I do not know how to calculate that time, but I would assume at leadt several years. That can be very important for a story. – Julian Egner Mar 6 '19 at 11:29
• Randall munroe did some calculations on the speed and possible obstacles what-if.xkcd.com/53 – Borgh Mar 6 '19 at 12:07

The average depth of the ocean is about 3,7 km about a third of the world is not-ocean. So the new average depth would be 3,7 + (3,7*(2/3)) = 6.17 km, or 2,46 km deeper than it is now.

So yes, there would be land. But only where we currently have reasonably high mountains. In Europe for example only the Alps and Pyrenees would remain above water. The only significant land mass left would be the Tibetan plateau I have made a map of Asia assuming water level is 2500m above sea level • So I need to search for land higher to 2,46 km to obtain our new map? Isn't Ice in the poles affected by the new water? – Malkev Mar 6 '19 at 11:15
• Total sea level rise if all the ice on earth melted would be less than 100 meters. So for the purpose of this question I ignored it. – Borgh Mar 6 '19 at 11:31
• I don't think doubling the amount of water equates to doubling the depth of the ocean. At the very least because $4\pi r^2 dr$ is increasing with $r$. – Alexis Mar 6 '19 at 11:58
• @Alexis, earth is large enough (and the numbers you find so big, for example the volume of earth is 260 billion km3, the water 1,486 billion km3) that in cases like this (adding a few km) you might as well approach it like a flat plane. – Borgh Mar 6 '19 at 13:05
• This is a good map, well made, but did we take into account that the area of the ocean increases as it fills? the larger the surface area the more water it takes to make it rise. It does seem you have done this but i just want to double check – Elias Rowan Albatross Mar 6 '19 at 17:00

Under the assumption that the new earth is exactly like ours, there will be small fraction of land available, when all the water in our earth flows to the new earth.

Just to explain more, lets assume earth's oceans contains around 3.5 kilometers of water. Ocean depth ranges from around few meters to even 10 KM. But for our calculation lets use the number 3.5 KM as average.

If this is doubled, the depth becomes 5.9 ~ 6KM. If our assumptions are right, then we can see these mountain ranges and structures with elevations > 2.5 KM in the new earth.

Edit : Corrected calculations. Thanks @Borgh, @Malkev and @Tim B