Campaign Scenario: Science at Lincoln Cave

[rust]

Scientist characters love to make important discoveries, and so my Pan-
dora setting also has to include at least some opportunities for them to do
so.

Once the first settlement on Pandora has been established, the explorers,
prospectors and scientists among the colonists will begin to explore the
planet in depth. Among the first places they will visit will be Lincoln Island,
named for the founder of the colonization initiative, Ian Lincoln, who died
in an accident before the colony was established.

On Lincoln Island the explorers will find the entrance to a cave that is par-
tially filled with rain water, but obviously once was below the sea level
and accessible from the sea, because in some of the rooms they will find
the remains of marine creatures that got trapped there and died when the
connection between the cave and the sea was lost.

If the scientist characters explore the cave and succeed with their skill
rolls, they will get some of the pieces of a scientific puzzle that will form
an unexpected image of their new home world:

- About 40,000 years ago Pandora had a much warmer climate and a
much higher sea level. When the climate became colder, polar ice caps
formed, much water became part of the polar ice caps, and the sea level
fell. This cut off the cave from the sea.

- The marine creatures discovered at the Lincoln Cave were part of a bio-
sphere that was completely different from Pandora's current biosphere. At
some time after the climate had changed, between 40,000 years ago and
the present, a mass extinction destroyed most of Pandora's native life,
and the few surviving species developed into Pandora's comparatively
sparse current biosphere.

A planetary climate that changes over time is no real surprise, although
the idea that warm Pandora currently has the equivalent of an ice age
and that the end of this ice age will raise the sea level and drown the co-
lony's settlement may be unpleasant.
The mass extinction event is something that urgently needs to be resear-
ched, because there could have been more such events in the past – and
whatever caused them may be able to cause a major natural desaster in
the colony's future.

 

[Dave Chase]

Don't forget to add a very few completely unknown life forms that have over the 40,000 years evolved very differently.

Though they have some common ancestor from 40,000 years ago, they are no longer the same in habits, instincts and reactions.

It would make for pleasant and possibly nasty surprise when they find a fresh water ______ fish that looks just like the friendly ocean fish that they have known about. Except this fresh water version attacks with a deadly posion which with 3 or more bites can kill a human.

Dave Chase

 

[rust]

Don't forget to add a very few completely unknown life forms that have over the 40,000 years evolved very differently.

Yep, thank you for a good idea.

 

[Captain Jonah]

So you are currently in the interglacial between ice ages.

Ok. FLoating or sub aqua cities are not bothered by changing sea levels, anything fixed to an island may be in trouble but you should have some warning as temperatures drop and satelites monitor increases in the ice mass at the poles.

You mention that 40k years ago was a high temp point and that the creatures in the caves were cut off and died after that but before now. So you had a very quick ice age which dropped sea levels significantly trapping the creatures. As the cave is still above water it seems you are in the warming period heading towards the next high temp point rather than going towards the next ice age.

There needs to be something, an orbital wobble perhaps, subtle and hard to notice but happening over a period of 10-30 thousand years that causes very short ice ages and periods of interglacial.
With each ice age the percentage of water frozen into ice becomes very high, salt levels in the remaining waters increase significantly and many life forms unable to adjust to either the lower temp or salt levels go extinct.

What you said suggests that the planet had an intensely cold but very very short ice age some 10 to 30 thousand years ago which then warmed up quickly and is still warming till the next one crops up in another 20 thousand odd years. This presumes that it is a very short cycle caused by an eliptical orbit, this however need not be the case. There could be a cyclic instability in the system sun which increases or decreases its output hence causing mini ice ages on the planet. Over a hundred thousand year period you go from intense ice age with water twice or more as salty as normal and very cold water to tropical temp planetwide with the eqators almost boiling, no ice cap, very warm surface water etc. Cold water loving life forms move up and down in depth to stay in the cold tem zones, some fish now in the lower depths may have lived close to the surface under the ice packs. Some warm water fish seen world wide may have hovered on the brink of extinction at the equator durring the cold temps.

 

[rust]

Thank you very much for your thoughts.

As for the warm and cold periods in Pandora's history, I will most probab-
ly use this explanation, with Pandora's sun as an (until now unrecognized)
long term variable star:

There could be a cyclic instability in the system sun which increases or decreases its output hence causing mini ice ages on the planet. Over a hundred thousand year period you go from intense ice age with water twice or more as salty as normal and very cold water to tropical temp planetwide with the eqators almost boiling, no ice cap, very warm surface water etc.

The mass extinction events - there will be more of them to discover - will
have a different, unrelated reason.
I think it will be something like an undiscovered brown dwarf that disturbs
the system's Oort cloud whenever it comes near the system, sending a
shower of comets into the inner system, which does not have any gas gi-
ants to "collect" at least some of those comets - so occasionally one will
hit Pandora, causing a mass extinction.

To find out about this, and about the timing of the next comet shower, the
characters will have to go on a long space trip with the colony's only small
spaceworthy boat ...

Edit.:
After a few calculations with the formulas from GURPS Space, the Brown
Dwarf would have a luminosity of 0.00004 (close to invisible from Pando-
ra) and a diameter of 196,000 km and would orbit the system's star in an
eccentric orbit at a distance of 106 AU to 1,445 AU and with a period of ca.
16,500 years.
So the last mass extinction event could have happened ca. 32,500 years
ago, while the last "visit" of the Brown Dwarf ca. 16,000 years ago did not
lead to a comet impact on Pandora.

 

[Silvereye]

A possibility for an extinction event:
You have said in other posts that the new colony is situated in the caldera of a massive, now extinct, volcano. How volcanically active is the planet, and could there be another massive eruption, or many smaller eruptions possible at various points in the surface. Berhaps a subsea flood basalt filled the sky with water vapour leading to a run-away greenhouse effect driving up the temperature and acidifying the oceans and the surviving creatures are happily eveolving into a form of Elasmobranchii as they could not form a calcium based (exo)skeleton.

While there are 'five great extinctions' in earths history, there are many many more that are much more localised (not planet wide). There is a pretty good summary of them on this wiki page (which you probably have already read with the "Nemesis Star").

National Geographic magazine actually has an interesting article about 'Blue Holes' in the August Edition that will probably be of great use to you. http://ngm.nationalgeographic.com/2010/08/bahamas-caves/todhunter-text While these blue holes are not rain filled caves, instead being more like a rain filled sinkhole that the have facinating prospects for doing what you are want with a not insignificant risk to your players.

 

[rust]

While there are 'five great extinctions' in earths history, there are many many more that are much more localised (not planet wide).

Thank you for the informations, this could be used as a good way to con-
fuse the characters during their search for the major extinction events'
cause and would force them to travel far and wide across the planet to
determine which event was local and which was part of a global desas-
ter.

National Geographic magazine actually has an interesting article about 'Blue Holes' in the August Edition that will probably be of great use to you.

Indeed, thank you very much for the link.

 

[locarno24]

Another one to bear in mind for extinction even evidence - since the colony is (at the moment) largely subsisting on mining activities, there's likely to be some geological surveys across fairly wide areas.

A classic one for them to come across (if someone thinks to look!) is the regular (ish) dust layers, identifiable by unusual trace elements. The KT event, for example, left a layer of high iridium concentration.

A suspiciously regular series of elemental dust bands in the geological record might get a suspicious type wondering what causes that sort of effect.....

 

[rust]

A suspiciously regular series of elemental dust bands in the geological record might get a suspicious type wondering what causes that sort of effect.....

Thank you for a good idea.

However, I think I will have to use something more specific to a water
world, perhaps something like "dead bands" of seafloor sediment lay-
ers which lack almost any microfossils or other signs of life ...

 

[locarno24]

Good thought. Although there's no need to be quite so obvious as to have fossils - soft micro-organisms will leave relatively limited fossil record anyway; it's more likely to be chemical traces.....e.g. a sudden carbon-rich layer (essentially a thin laminar coal deposit) amidst silicate-based sandstone.

 

[rust]

e.g. a sudden carbon-rich layer (essentially a thin laminar coal deposit) amidst silicate-based sandstone.

Yep, that's it - bought, thank you.