In need of a major desaster

[rust]

The work on one of the scientific mysteries of my Thalassa
setting has led me to a point where I need a major natural
desaster, an extinction event able to wipe out almost 100 %
of all life forms at and near the ocean's surface, but with-
out such consequences for most of the deep sea life forms.

This looks more like some offworld event than like an event
on the planet itself, I think. It should be something which
leaves few material evidence (so no asteroid impact, which
would leave a crater), but there should be an at least small
probability that a similar event will happen again in the not
so far future.

There are a number of options, for example a strong gamma
ray flash (not very likely) or a massive solar flare (currently
my preferred version), perhaps also an extreme ice age cau-
sed by a variation in the star's luminosity or by the passage
of the entire system through an especially dense cloud of in-
terstellar dust.

If you can think of any other at least somewhat plausible de-
saster, please let me know, I would prefer to use something
I have not already used in any previous setting.

Thank you.

 

[DFW]

A very close neighbor star underwent an event (merging with a dwarf companion?) causing nova levels of radiation emission for a period of ~week. This killed life in the upper level of ocean due to radiation...

 

[BFalcon]

Massive underwater volcano eruption - causing sulphurous water towards the surface before it could dissipate. Ash cloud spreading throughout the globe before settling on the surface, causing the water temperature to plummet and then be suffocated by the mixture of dissolved ash and nitrates from rotting fauna in the water?

Scout mission unknowingly brought a new disease to the planet which wiped out all of a handful of species. Unfortunately, several species depended on these smaller creatures so died from starvation and the knock-on effects have reverberated up the food chain. Luckily the deeper food chain is based more on scavenging, so have been doing fine. They are currently living off smaller creatures who happily feed off the algae that thrive around the volcanic vents in the deeper trenches...

Unfortunately, whatever you do, the deeper sea creatures are likely to depend on the surface creatures for food in some way or another.

 

[AndrewW]

Some large mass object passing nearby causing part of the atmosphere to be lost?

Or there's always a ship that turns into a giant maid with a vacumn cleaner that sucks the planets atmosphere away...

Early attempt to terraform the planet? The records for which have since been lost, or perhaps it was done secretly.

Passing comet (or whatever object) brought a biological organism that killed off or mutated the upper layers of life?

Toxic gases released from underwater vents? The gases are harmless until the receive a small amount of sunlight and become active so until they reach the upper layers they don't have any effect on the life.

 

[rust]

Thank you all very much for your ideas.

Unfortunately, whatever you do, the deeper sea creatures are likely to depend on the surface creatures for food in some way or another.

This is what the scientific mystery is about. :wink:

The (mostly extinct) surface life forms and the deep sea life forms
have completely different and incompatible biochemistries and ge-
netics, they are not parts of the same biological evolution. More-
over, there seems to be evidence that all the life forms of the deep
sea ecology have been genetically modified, and have been intro-
duced from some other planet.

However, this and the various hints at the species who did this, why
these aliens did it, and what became of them, the characters will be
able to learn over a longer period of time, with about one discovery
and insight per game year.

This all will start with unexpected predator attacks on the colony's
aquafarming fish schools. No exploration report mentioned any big
predators, only several species of harmless plankton, so the colo-
nists are not prepared to fight sea "monsters" with the size and fe-
rocity of a dunkleosteus.

The problem is that the explorers of the planet missed the deep sea
life forms completely, and calculated from the little biomass of the
surface life forms that there could be nothing important down there,
at best some small scavengers crawling across the sea floor.

And while the deep sea predators never came close to the surface
for millenia, because there was no suitable prey for them after the
desaster which killed almost all surface life, the colonists were so
kind to introduce lots of fine seafood which attracted the deep sea
predators.

The fact that the deep sea predators are able to hunt near the sur-
face is one of the pieces of evidence that there once must have been
suitable prey for them up there, otherwise they would hardly have
developed the ability to withstand the pressure differences between
their natural habitat and the surface region so well.

Looking closer, the colonists will be able to find fossils of a rich surfa-
ce biosphere, which should lead to the question why it became ex-
tinct, and whether this extinction event could happen again during
the existence of the colony.

Well, and then there are the wreck of an alien floater (surface ship),
a well preserved, but entirely cleared alien outpost, and other disco-
veries to make ...

 

[phavoc]

You could also bend your disaster planning on ear by making it a man-made one... or perhaps it would be more correct to say a grandfather's children-made disaster.

So say you had a grandkid who had a lab on the planet. Some experiment went wrong and all kinds of havoc occured in the biosphere. The kid leaves for a new planet elsewhere that's not all mucked up, and everything left behind has to fend for itself. All of this starts to come out when your adventurers accidentally stumble upon some clues... and the lure of ancient tech is a powerful one (and who knows if they'll find any?). You could also include a reason why they need to find the lab (some automated process is gonna kill the planet, or cause another disaster and they only have 30 seconds... better hope McGuyver is there!).

You could also have instead on one grandkit, there were two... and they were trying to out-do the other in their crazy experiments, and the collapse of the biosphere was caused by them warring with each other using new plants and animals. Even more chances to find ancient tech!

 

[rust]

Thank you very much.

I have not yet decided whether there is a connection between the
background plotline about the different ecologies of the planet and
the alien visitors on the one hand and the extiction event on the
other hand. Right now I would prefer to keep them unconnected,
although the characters would of course suspect a connection and
keep searching for it.

 

[Rick]

I can think of 2 possible ideas, 1 natural (ish), 1 artificial. The natural one could be runaway global warming!! The original water level of the planet was much lower (some land area + big ice caps) - planet warmed up, water level rose and the predator population in the shallow water area suddenly had more food (land animals getting used to swimming!). Predator numbers went up, then fed themselves into extinction!
The artificial one would involve some form of terraforming. The planet originally had a much lower atmospheric oxygen content and the indigenous lifeforms had an intolerance to high levels of oxygen. Some helpful souls decided to terraform the planet by introducing an oxygen-producing algae and killed off the indigenous life.

Any help?

 

[rust]

Any help?

Of course, every idea is most welcome, although I am not yet sure
which one (or which combination of several ones) I will use in the
end, it will depend somewhat on the various other plotlines of the
setting and how I can tie them together.

 

[Dave Chase]

Have some type of algae bloom.

Due to some alien races doing a waste dump from their ship while over oceans of worlds during their approach to the down port, some of the mild mannered, algae have found such to their liking.

This has not be an issue and has of yet to be fully discovered or researched.

A few days before this explosion of algae growth, there were 6 ships from the _______ in one week where normally only once or twice a month would the colony see that many ships from the ______.

Accident, intentional or ???

Dave Chase

 

[rust]

Thank you very much for that idea.

I think this would make a nice new, later plot, an (incidental ?)
introduction of something which endangers the colony's aqua-
culture.

Thinking of the hostile relations between the colony and Earth,
it could well be a "black operation" by the Earth's government,
carried out by hired aliens, to destroy the colony.

 

[Jak Nazryth]

How about a Caronal Mass ejection but from an ancient military experiment? Similar to the movie "Knowing" but because of an early star-trigger device? Maybe there was a war and the attackers (out of system) attacked the defenders/victims (on your planet). Wiped out most life but there could be old, very damage artifacts from the long dead civilization. "Melted" left overs?

 

[Jak Nazryth]

I cannot remember the name of this theory, but I saw this on the science channel several years ago. A geologist back in the 30’ or 40’s hypothesized that some time in the very distant past, the earth’s mantle grew so hot, that the entire crust of the planted “shifted” or “rotated” completely 90 degrees around the earth’s axis. So the north and south poles, which were at one time on the equator, and within a year or less, they traded places with the land masses that are currently on the equator. He likened it to the skin of an orange suddenly getting loose enough to slide freely around the inner juicy fruit. I remember from the program, the only scientist who was intrigued about his theory was Albert Einstein. Sorry but I don’t remember the original geologists name or the name of his theory, but I think it might have been called “loose crust theory”.
Anyway, that would cause major devastation in a planets Eco system.

 

[rust]

How about a Caronal Mass ejection but from an ancient military experiment?

This is a very interesting idea, thank you for it.

Reading up on stellar flares, I had just realized that Thalassa's star
is not the right type for an extremely powerful flare - but this is of
course true for naturally occuring flares only. Something like an an-
cient satellite hidden in the star's outer corona which triggered ex-
treme flares under certain conditions, for example when starships
of other species operated in the system, but which is now malfunc-
tioning and triggers only occasional and nowadays usually minor fla-
res, making it difficult to find out what was and is going on ... really
a very interesting idea.

 

[rust]

Sorry but I don’t remember the original geologists name or the name of his theory, but I think it might have been called “loose crust theory”.

Thank you again.

This one sounds a bit weird, but I will try to find out more about it.

 

[Reynard]

Your planet might be in a period similar to Earth's Paleozic age 400-535 million years ago. Animals and plant were just beginning to emerge and establish on the coasts. At some time, and this can be very recent, a global disaster such as a super volcano, dumps ash and toxic gas into the atmosphere which cools the globe and also dissolves into the world water bodies killing a great deal of coastal and surface marine life forms down to all complex cellular bodies.

Evidence would be a layer of ash worldwide heaviest at the epicenter. Depending how long you had the event occur, the perished life could be fossilized and a geological layer or a mix of ash and organic matter since bacteria could survive and feast from decades to eons.

Just for curiosity, what is the planet's physical world code?

 

[BFalcon]

Reynard: already suggested that one myself - you just put it better...
(Right at the top (4th post?) on page one... great minds, eh?)

 

[rust]

Your planet might be in a period similar to Earth's Paleozic age 400-535 million years ago. Animals and plant were just beginning to emerge and establish on the coasts. At some time, and this can be very recent, a global disaster such as a super volcano, dumps ash and toxic gas into the atmosphere which cools the globe and also dissolves into the world water bodies killing a great deal of coastal and surface marine life forms down to all complex cellular bodies.

Evidence would be a layer of ash worldwide heaviest at the epicenter. Depending how long you had the event occur, the perished life could be fossilized and a geological layer or a mix of ash and organic matter since bacteria could survive and feast from decades to eons.

Thank you (and BFalcon) very much for this one, I think I will
use it for an earlier extinction event on Thalassa - a good op-
portunity to design the planet's prehistory, something to disco-
ver bit by bit for the marine biologists among the characters,
or to reveal as a part of the setting's background colour.

Just for curiosity, what is the planet's physical world code?

The data below, from the top down, are:
Year
Day
Axial Tilt
Diameter
Gravity
Atmosphere (nitrogen-oxygen)
Hydrographics
Volcanism (low)
Tectonics (low)
Resources
Biosphere
Biochemistry

The orbital radius is 1.25 AU around an F9 V star.

The second part of the UWP ... I do not think that the small colony's
society would fit into Traveller's UWP scheme. It could perhaps be
described as a direct democracy with a moderate law level and a tech-
nology level of approximately TL 9, but without gravitics.

 

[Rick]

I'm guessing that the planet either orbits a hotter star or is closer in than Earth. Judging by what you've put up, I'd guess it's 1-2 degrees hotter; cold enough to form pack ice at the poles, but not permanent ice caps, warm enough to be uncomfortable at the equator? I'd suggest that it would be a perfect breeding ground for algae and plankton - especially near the equator, you might get miles-wide mats of the stuff, a few metres thick. Enough to be a hazard for surface navigation.
How about floating algae farms as a secondary economy? A combined harvester/processor to convert the algae into food, fuel?, other items (ran out of things that you could use algae for after those 2! )

 

[rust]

Thalassa's average temperature is 22° Celsius, so it is indeed quite
a bit warmer than Earth. Because of the low axial tilt of only 8° it
has almost no seasons and the temperature differences between
the poles and the equator are lower than on Earth.

Algae are indeed a main product. They are used as food, for the co-
lonists as well as many of their aquaculture animals, and as raw ma-
terial to produce bioplast, used for much of the colony's equipment
from "paper" to furniture. Another planned use of the algae is phyto-
mining, where genetically modified algae accumulate metals, for ex-
ample magnesium, from the sea water for industrial use or export.

"Right now", at the campaign's start, the algae production will just
be sufficient for the colony's own needs, and there are / will be some
serious problems with the algae's adaption to the new environment,
but in the not so far future algae products from algae beer (absolu-
tely disgusting stuff, at least for humans) to pharmaceuticals are in-
deed likely to become important secondary exports.

This is, provided the characters find customers for the stuff ...