[Hannah LS (OP)]

Colin asks:

Regardless of how many days and nights it rains, is there enough water in the Earth's climate system for the entire Earth to actually flood?

Any thoughts?

[alancalverd]

No. But if (when?) all the ice melts, quite a lot of the habitable and cultivable surface will be flooded.

[Janus]

Depending on the estimate, if all the available ice in the world were to melt, the ocean level would rise 70 meters.   The vast majority of what is now dry land would still be above sea level,

Here's a representation of what the US might look like:


Though this doesn't show fine detail.  For example, it shows Portland, OR as still being well inland.  However, Portland is right on the Columbia River which connects directly to the Pacific. The river level would also rise flooding a majority of the city and down into the Willamette valley( where a lot of that cultivatable land alancalvard mentioned is) .

[Bored chemist]

Here's a representation of what the US might look like:


Though t

I'm trying to work out if that's a failed image or just irony.

Anyway, if nothing else happened + the  Sun, Moon and the Earth carried on for long enough, the Earth's radioactive heat would eventually fall to the point where tectonic activity stopped.
So there would be no new mountains.
But the weathering would continue so, eventually, the high ground would be weathered away and all the surface would be water.

In reality the Sun will go red giant before that happens

[Halc]

You just stop tectonic activity, and erosion will push all the land into the oceans.
Poof...  A world totally under water.  It's only the plates shoving up new mountains that keeps that from happening.

[Bass]

There have been times in the geological past where most of the continents were under water. One possible cause is the breakup of supercontinents.

[chris]

You just stop tectonic activity, and erosion will push all the land into the oceans.
Poof...  A world totally under water.  It's only the plates shoving up new mountains that keeps that from happening.

Fascinating thread; thanks.

Have we actually got enough water on Earth for this to happen? How much water do we anticipate would be locked up as ice under these scenarios?

[Janus]

You just stop tectonic activity, and erosion will push all the land into the oceans.
Poof...  A world totally under water.  It's only the plates shoving up new mountains that keeps that from happening.

Of course before this could happen naturally, our Sun will have increased its output enough to have boiled the oceans away.

[evan_au]

Another possible scenario is when the Moon was much closer than it is now.

Tidal forces follow an "inverse cube" law, so when the Moon was 10x closer, tidal forces would have been 1000x stronger - imagine a +/-1km tide! That would create an incredible amount of erosion - perhaps even enough to erode mountains faster than tectonic forces could push them up?

If so, the result could have been like the movie "Interstellar": a twice-daily tsunami surging around the globe...

[chris]

Tidal forces follow an "inverse cube" law, so when the Moon was 10x closer, tidal forces would have been 1000x stronger - imagine a +/-1km tide!

Can you explain how that works please Evan? I don't see where the cubed bit comes from...

[Halc]

You just stop tectonic activity, and erosion will push all the land into the oceans.
Poof...  A world totally under water.  It's only the plates shoving up new mountains that keeps that from happening.

Fascinating thread; thanks.

Have we actually got enough water on Earth for this to happen?

In theory, a cubic km would do if the land was flat enough.  But as Janus points out, tectonic activity will stop long after the oceans have boiled away, which is not too long from now.  For that matter, the Earth will be destroyed before tectonic activity stops.

How much water do we anticipate would be locked up as ice under these scenarios?

That's interesting...  Assume climate is the same as now, and tectonic activity has ceased and the planet is totally flat with uniform depth ocean.  How deep does the water need to be to prevent all of it from finding its way to being ice at the poles?  If that happened, there would be a lot of land, and it would probably absorb more sunlight, warming it enough to melt that ice, and it only takes a trivial amount of icemelt to cover the Earth at a trivial depth.  You just need an equilibrium that melts ice faster that it builds up (snows).

[Halc]

Another possible scenario is when the Moon was much closer than it is now.

Tidal forces follow an "inverse cube" law, so when the Moon was 10x closer, tidal forces would have been 1000x stronger - imagine a +/-1km tide! That would create an incredible amount of erosion - perhaps even enough to erode mountains faster than tectonic forces could push them up?

Interesting choice of distance.  At 10x closer, it puts the moon about exactly at geosync, so there would be no tides at all.  If it was just a little off, yes, there would be time to form tides at full height, but also the crust of earth would bend back and forth, heating it dramatically.  Maybe the heat of that would boil away the water.

Can you explain how that works please

From wiki on tidal force:
"The tidal force acting on an astronomical body, such as the Earth, is directly proportional to the diameter of that astronomical body and inversely proportional to the cube of the distance from another body producing a gravitational attraction, such as the Moon or the Sun.
...
Figure 3: [Graph showing a simple plot of Y=1/X²]
...
In this graph, the attractive force decreases in proportion to the square of the distance, while the gradient (slope) decreases in direct proportion to the distance. This is why the gradient at any point is inversely proportional to the cube of the distance.

The tidal force corresponds to the difference in Y between two points on the graph, with one point on the near side of the body, and the other point on the far side. The tidal force becomes larger, when the two points are either farther apart, or when they are more to the left on the graph, meaning closer to the attracting body.

For example, the Moon produces a greater tidal force on the Earth than the Sun, even though the Sun exerts a greater gravitational attraction on the Earth than the Moon, because the gradient is less. The Moon produces a greater tidal force on the Earth, than the tidal force of the Earth on the Moon. The distance is the same, but the diameter of the Earth is greater than the diameter of the Moon, resulting in a greater tidal force."

[Stephbaker]

Colin asks:

Regardless of how many days and nights it rains, is there enough water in the Earth's climate system for the entire Earth to actually flood?

Any thoughts?

I guess if it rains on all of the continents at the same time then maybe it could lead to flooding. But there should be enough water in the seas to keep the lands underwater. The normal setting is that the water from land flows into the waterbody giving us the land back. We already have enough on earth to put the whole of earth underwater. If the glaciers melt the whole of earth will flood due to increase in sea levels