Rainworld

[balzacq]

Just saw a program on the Science Channel called "Miracle Planet". This episode focused on the effects of a major (2000km) asteroid impact, which would essentially destroy the earth as we know it. They called it a "total evaporation event" since the heat of impact would completely boil off the oceans and eliminate all life except for deep-rock anaerobic bacteria. They mentioned almost in passing that it would take a thousand years for the earth to cool enough for the water vapor in the air to start raining out, but then it would rain at tropical rainforest intensity.

Now, when I was in high school, I read an SF novel in which one scene took place on a planet where it rained torrentially all the time, and I always thought that was kind of neat. (Can't remember anything else about the novel, however.)

Some googling and back-of-the-envelope calculations (literally!) gave me this result:

Earth ocean volume: 1.35e9 km^3
Earth surface area: 5.09e8 km^2
= even layer of 2.65 km over the whole Earth
Rainforest precipitation (Manaus, Brazil): 2.1 m/year
Time to rain out oceans: 1261 years

Imagine an earthlike world that had one of these strikes ~1500 years ago and was discovered ~800 years ago. Assume that the greenhouse effect of the water vapor is cancelled out by the increased albedo of the cloud cover. All local life was destroyed, so any life forms would have to be imported, and would have to survive in constant cloudy conditions. It would be hot and incredibly humid. And it would rain buckets all the time, everywhere.

Since I live in Seattle where it only feels like it rains all the time, I think this is a fun idea to torture my players with.

Comments?


-- Bryan

 

[Valarian]

Hmmm ... Hot, humid, rains all the time.

I feel a garden world with a global tropical rain forest coming on. Would have to be low light plant species (ferns?). Carnivorous plants?

Could you get this climate without the total extinction event?

 

[archhealer]

"Looking for him, Mmmmm? Found him you have..."

 

[TheEngineer]

Perhaps a different view:
In a cold, cold, dangerous and life unfriendly universe this planet still could appear to many space folks as a kind of natural recreation and wellness center

Besides:
In Seattle I learned, that its quite ok to go out for drink and billard wearing just shorts, a rainsuit and waterproof hiking boots

 

[Ptah]

I like it, and so would my amphibian friends.

 

[jasper]

You maybe thinking of Midworld by Alan Dean Foster.

 

[Fritz_Brown]

Thread Hijack Alert!!
This brought to mind a story I read several years ago that had been written decades befoer that. The protagonist is a hired gun whose weapon literally leaps into his hand. He is "hired" to go save a colony on a planet that is trying to kill them. IIRC the main problems were actually the plants on the planet.

Does anybody remember what book this is, and who the author might be? I cannot find the right word combo to make Google tell me....

Edit: Well, doggone it, I should have known. Deathworld by Harry Harrison is the book for which I was searching. (And I found it on a site I have visited before about scifi weapons.)

OT: Maybe the "extinction event" killed off all the animals, but plant life flourished. And it is now very pissed.
end edit

 

[balzacq]

Originally posted by Fritz88:
Thread Hijack Alert!!
This brought to mind a story I read several years ago that had been written decades befoer that. The protagonist is a hired gun whose weapon literally leaps into his hand. He is "hired" to go save a colony on a planet that is trying to kill them. IIRC the main problems were actually the plants on the planet.

Does anybody remember what book this is, and who the author might be? I cannot find the right word combo to make Google tell me....

Deathworld by Harry Harrison.

 

[Fritz_Brown]

Did my edit without refreshing! Thanks, balzacq!

 

[balzacq]

Originally posted by Valarian:
Hmmm ... Hot, humid, rains all the time.

I feel a garden world with a global tropical rain forest coming on. Would have to be low light plant species (ferns?). Carnivorous plants?

I was imagining lots and lots of bamboo, kudzu, ferns, and rapidly spreading rainforest tree species, which probably wouldn't have had a chance to form a mature triple-canopy forest yet.

Originally posted by Valarian:
Could you get this climate without the total extinction event?

IANAC (I am not a climatologist), but I suspect not -- without a massive event to put all the water on the planet into the atmosphere, you'd have a normal differentiation of climates into arid/rainy zones.

I suspect that even given the Rainworld scenario you'd still have differentiation -- the poles would still be colder than the equator, and would probably snow out much quicker.

You'd also have massive erosion, torrential rivers, and (I think) massive lakes formed by hydraulic damming at chokepoints.


-- Bryan

 

[parmasson]

Well it would be a barren wet place to be sure. With nothing but bacteria left no plants to speak of, just miles upon miles of mud canyons. With the increased reflectivity of the atmosphere would that bring the average temp DOWN?

 

[balzacq]

Originally posted by Kurega Gikur:
Well it would be a barren wet place to be sure. With nothing but bacteria left no plants to speak of, just miles upon miles of mud canyons. With the increased reflectivity of the atmosphere would that bring the average temp DOWN?

Dunno. The program suggested that the latent heat from the atmosphere being suffused with vaporized rock was what kept it hot. Once it got cool enough to rain (100C, right?), I would think it would cool off more rapidly as it rained, down to merely "hot".

But since I don't think the atmospheric composition would change much (not enough time for the oxygen to react out), a smart terraforming effort could lead to exponentially expanding plant growth. I think after a hundred years it might be pretty lush. But still raining.


-- Bryan

 

[kafka47]

Originally posted by Kurega Gikur:
Well it would be a barren wet place to be sure. With nothing but bacteria left no plants to speak of, just miles upon miles of mud canyons. With the increased reflectivity of the atmosphere would that bring the average temp DOWN?

Ah, I see that you have visited England...

 

[Andrew Boulton]

I was going to slap you, but then I looked out the window...

 

[Maladominus]

Originally posted by balzacq:

Imagine an earthlike world that had one of these strikes ~1500 years ago and was discovered ~800 years ago. Assume that the greenhouse effect of the water vapor is cancelled out by the increased albedo of the cloud cover. All local life was destroyed, so any life forms would have to be imported, and would have to survive in constant cloudy conditions. It would be hot and incredibly humid. And it would rain buckets all the time, everywhere.

If it rained all the time, and there is no time for the water to evaporate (or dry up).... then that planet's surface would pretty much be covered entirely in water, don't you think?

 

[Fritz_Brown]

I would think plants would recover fairly quickly, as they have the advantage of being dormant in their seed stage. (And, so, they survive things like forest fires all the time....) So, the plants would come back pretty quick, and a few types of bugs would then revive.

The problem really, with the scenario, is the depth of the ocean beds. You are going to get a massive climatological change from the ocean floor to the continental shelf (much less to the top of Ararat).

I also think anything that boiled the oceans (totally) would actually cook off a good portion of the atmosphere (it would cause expansion past the edge of the gravity well). And, a lot of the water vapor along with it.

Hey, just doing my part to spoil the fun by intruding realism....

 

[balzacq]

Originally posted by Maladominus:
If it rained all the time, and there is no time for the water to evaporate (or dry up).... then that planet's surface would pretty much be covered entirely in water, don't you think?

Well, the water would just run back into the oceanic depressions that it originally occupied.

And the show, at least, asserted that the Earth's gravity would hold on to the atmosphere.

As a side note, if a 2000km asteroid at orbital velocity won't do more to the integrity of the Earth than leave a giant scar, maybe it's harder to crack a planet than the authors of Traveller thought, or else the Ancients must have used something truly cosmic.

<whisper>and maybe the "near-c rock" isn't the abomination we've all been told...</whisper>


-- Bryan

 

[sid6.7]

i think balzacq your thinking of a ray bradbury
story that was also made as TV show...

it takes place on venus where it rains 24hrs a day
they've crashed and are trying to head to a dry "sun dome" habitats that are all over but the
plants grow so fast they seem alive and they destroy all of the domes that they find....

if a remember correctly its mark singer is the
actor in the tv version...

 

[Kirth]

One major problem with this world would be the answwer to the question: "What about plate tectonics?"

Once all the water is evaporated, then the ground would be fry and barren until the temperature could come down enough to allow for rainfall. The problem is that the water helps drive the plates today. If you take away the water, movement of the plates would be large lurches as the strata breaks. This would lead to much more severe earthquakes and volcanic activity. There would be more major eruptions. This would do one of two things, make the atmosphere thicker and more acidic(Venus) or it would create more of an ash shield to block out the sun causing temperatures to fall faster. That would shorten the timeframe and also make a particularly nasty acid rain until the enough of the ash and dirt is scrubbed out of the atmosphere. Of course, if this happened, the shorter timeframe would also lead to a lessening of the tectonic activity as more water greases the wheels of shifting plates.

 

[parmasson]

I would think plants would recover fairly quickly, as they have the advantage of being dormant in their seed stage. (And, so, they survive things like forest fires all the time....) So, the plants would come back pretty quick, and a few types of bugs would then revive.

I am not sure. How much heat would it take to vaporize ALL the water? From what I know if you raise the ambient temp above 240 F for a few years most regular plants would simply die.

If those seeds were denied light and temps over 212 F for years. I wonder if any complicated lifeforms would survive.

that it would take a thousand years for the earth to cool enough for the water vapor in the air to start raining out . . .

We are talking about restarting the planet’s biosphere from an early stage. A whole new evolutionary process (if it even took off again) might take hundreds of thousands of years.

Massive erosion from the constant rain could remake the landscape in a matter of months.