That doesn’t say whether it put paid to the majority, or just the last few stragglers. I’m looking for a cite that most dinosaurs survived the immediate first effects (say, the first month)
Oh, and as for this:
But this is very much an IMHO question, as it invites pure speculation on what people will do. Obviously mod-dom has seen fit not to move it, but it’s not a factual question in the slightest.
Let me know if you find it!
As for me I’ve made no claim one way or the other that “most dinosaurs survived the immediate” impact or even that “most” species did.
No cite for the following, just a thought process.
If I am understanding you correctly you believe that few species survived the firestorm stage, which was fairly uniformly devastating across the globe with a few areas more hellscaped than others. Those few survivor species somehow favored those of smaller size (inclusive of mammals but also smaller lizards and snakes) and avian dinosaurs. I am not sure what you propose as the mechanism by which the smaller were preferentially able to survive global firestorms. I can make up a story for mammals - maybe they were burrowing mammals and escaped the fires by going underground? Far enough to not get cooked? Okay I doubt that … and it doesn’t explain why other smaller species survived better too. Not too many burrowing birds … Not a lot of decomposing organic material either as it almost all burned up. So bye bye worms.
Alternatively no matter how wide or localized the firestorms were, impact winter was global. So let’s instead assume that some significant fraction of the world did not experience immediate devastation. Photosynthesis came to a near halt. Plants in areas not immediately devastated, whatever fraction that was, died globally. Animals and insects dependent on those plants died, be they pollinators, leaf eaters, frugivores … those who ate those species died and those who ate those creatures died with a collapse of the food chain. The new food chain for the duration of impact winter and a bit after was decomposing dead organic material (back to thinking about worms) and seeds that the plants had left behind, and then maybe a few animals one trophic level up that ate the worms, birds, insects, and small mammals that ate that.
Which hypothesis (across the globe species death by firestorm or by impact winter) better explains why across species, mammals to avian dinosaurs to lizards and snakes, smaller species eked by more often?
I was thinking that an impact like the dinosaur killer would have the effect of making the earth’s crust “ring like a bell” to some extent, so that no coastal area was safe, and possibly not even lake coastal cities. See how much devastation waves of only about 10 feet did to the Indian Ocean communities, and consider what could happen if a major sloshing event hit anywhere/everywhere in the world. My though was that even in the areas not devastated by fire and ejecta, there would be the world-wide equivalent of a high-number Richter event, especially under the seabed also. Tsunamis are a result of very localized plate movement (IIRC the Indian Ocean quake moved about 100 miles of plate at the fault line vertically only 10 feet or so)
I guess another question is how much ejecta and how high? Presumably, most would be suborbital height and return to earth, I know not where, within an hour or much less. very little would soar to multi-hour heights? But that is gut feel, I don’t know the actual math. We haven’t discussed the physics of the air/water vapor shock wave. (There’s some classic footage of simulated housing being flattened by the shock wave air blast from test nuclear explosions.) I assume being behind a mountain range or several from the blast would lessen the effect?
How long does nuclear winter take to set in? I haven’t seen any data on that. Obviously with clear skies, the temperature can drop to below freezing very quickly. Is a large amount of suspended dust transparent to IR radiation and things freeze within days, or will it be like a greenhouse? On such details hinges the possibility that Bob or Fred will last long enough that we can have him for dinner one night. We gain a few more days’ grace if Bob and Fred are well done before the cold arrives.
I think too, another factor would be that if a large target were detected and fragmented far enough out, a significant number of resulting expanding cloud of fragments would miss the earth. I’m think of modified Saddamizer bunker busters, modified to use thermonuclear warheads and explode a calculated distance under the surface to maximize dispersal. Rinse and repeat with the bigger fragments. This should reduce the risk and damage by at least an order of magnitude, maybe two, over 10 years.
This maybe a very stupid question but I have no background in astronomy.
In regards to detection of asteroids and/or comets how likely is it we would be able to detect an object with a highly irregular orbit. I am thinking along the lines of an object with an orbit that is virtually perpendicular to Earth’s plane of orbit. I mean space expands out vastly in three dimensions; are we currently monitor that level of coverage?
A question to help me understand the idea of fleets of nuclear rockets scenario - what are the relative speeds of our rockets and Dinokiller asteroids?
If they are more or less the same, does that mean if we spot the Dinokiller 10 years before it is going to impact Earth then, at best, we’d intercept it with our first rocket at Year 5?
While a crewed flight to Mars takes 7ish months, can an uncrewed bomb on a rocket be made to travel appreciably faster?
You are correct. You just said “many”. I still disagree.
No, I believe that few species survived the firstorm, tsunami, acid rain and unfiltered UV stage.
I’m not saying they had to be built to survive the first few days.
I agree that there would be patches of survivors of all groups in the first few days, even with global firestorms and tsunamis.
But in the first few months, the real filters kick in. For birds, it seems a big determinant was whether a species was arboreal or not.
No, that is not correct.
Funguses prolifertated immediately after the impcat because of an abundance of substrate.
Up to 23% of the vapour plume portion would hit escape velocity. Debris would still be returning to Earth days later. Only 25% accretes in under 2 hours. 15% of it is still up there 4 days later. Cite.
Not much at all. All current detection efforts I know of focus on the known groups in the ecliptic. Something that unusual is going to rely on some lucky and competent
amateur.
Sorry, I made a mistake there - 12%, not 23%.
Also, I do actually know how to spell “proliferated”. And “impact”. But that sentence was a very hasty edit before the 5 min window ran out.
And no, “funguses” is a perfectly acceptable English plural.
The firestorms, tsunamis, and acid rain are all part of what gets referred to as the firestorm stage - a short hand for the immediate several days. Unfiltered UV is on the time course of impact winter.
What fraction of terrestrial species do think were done in by tsunamis?
What do you think those filters were, that relatively advantaged smaller species? Especially in the context that you propose with most of the world’s landmass (excepting that covered by water from tsunamis) having been consumed in firestorms, leaving mostly inorganic ash behind?
The bird bit. Yes, it fits exactly the second hypothesis! (That the big filter was surviving global winter.) First of all the ones that survived were best built for eating seeds, which would have stayed around left over after plants otherwise died. Fewer of them if most was consumed in fire.
And of course trees, along with most other plants, died off during impact winter. The complete ecosystems requiring them collapsed too.
Your article particularly makes the point that deforestation was a “succession of events”, not just the immediate event … but most importantly a global firestorm would have burnt up a majority of organic substrate, pushing its carbon immediately skyward, while the ecosystem that was emergent of global winter “prolifertated immediately after the impcat because of an abundance of substrate”
Your fungus article explicitly does not state fungus grew first in the aftermath of forest fires, but in the aftermath of a “wholesale dieback of photosynthetic vegetation … global dieback …” favored precisely because of the abundance of substrate and being favored by reduced sunlight.
So thank you for the supporting citations. Many species likely survived the immediate post-impact period, in areas relatively unaffected by firestorms or tsunamis. The world for the next several years though did not have sunlight at its proximate base. It had leftover seeds from plants that had died for lack of sunlight and due to cold. It had organic substrate from dead plants and dead animals to feed fungi and worms. And it had a small ecosystem sustainable of animals that could live off of those seeds, those fungi, those worms, and a level that lived off of them some too.
In short the species filter was likely less surviving the immediate effects of impact than being able to make it through global winter. The question for civilization would be if humans could make it through with knowledge and know how intact, ready to adapt to the new world.
One idea for making it through impact winter as humans is fungus and worm agriculture. Pretty sure crickets and cockroaches could be farmed at industrial scales in compost piles as well.
I don’t see subsistence sheep farmers producing the protein needs in this future.
You can, of course, cite that, what with this not being IMHO…
No, it’s an immediate effect of the returning ejecta, and likely only lasted months, not years.
Specifically by tsunamis? Only ones that were endemic to what is now the Gulf area. We’ve seen the total destruction that seismic wave effects wrought 3000 km away. So anything closer than that would be toast if it was endemic. By analogy with existing species distribution (bearing in mind our concept of endemic species is very loose for that far back), somewhere between 5-10% of those. Further afield, that drops down quite a bit, obviously. Well, until you get to the area around the antipode, where it picks up again.
More generalism, ability to burrow, less nutrition needs, relative individual abundance.
It also fits the earlier death hypothesis. The trees go in the firestorm, and immediately there’s no place for arboreal species (the ones that don’t just die in the blazing forests). No need to wait years for them to die out, they’re vulnerable immediately. Most animal species are very niche-dependent.
I didn’t say it did. I was citing it as proof that everything organic wasn’t “all burned up”. It was also defoliated by acid, and killed by excess UV, and washed up by kilometre-high waves.
You can, of course, cite this, this not being IMHO and all. Not your own just-so stories, but a recent paper with species survival timeline estimates.
But I do see you are walking back the “everything organic was burned up”, that’s progress.
Compost piles require something to compost. And more energy input than you take out.
Well, not if they’re also feeding airship researchers, fuel cell engineers, platinum smelters and antibiotics makers, they’re not. Kind of my point.
This has gotten past tiresome …
Unfiltered UV radiation was " an immediate effect of the returning ejecta, and likely only lasted months, not years"? Where do you get this idea?
According to the experts anyway, particles and gases depleted the ozone layer over several years as the likely time course and mechanism.
The are divergent opinions on exact extent and timeline of course, but the common thread is that the soot that is blocking light is simultaneously causing depletion of the ozone layer, which leads to more UV.
Other than the idea that some small species may have tended to live in burrows that were deep enough to have survived intense firestorms above them, heating up the ground, using oxygen, and spewing carbon monoxide (which seems like quite a claim but fine), all of those share in common one thing: the terrestrial species that came out the other side had no advantage in survival of the firestorm (or tsunamis or acid rain that followed); they had advantage in surviving the collapse of the previous food chain.
A belief that large portions of the world’s landmass (not just coastlines) was impacted by tsunamis needs some academic support. I can find a study that says most coastlines would have experienced something significant, and “tsunami wave heights in the Pacific and Atlantic basins would have been as large as 14 meters”, getting bigger as they slowed down near land, would have been horrific for miles inland at some locations to be sure …
But let’s focus on what you are saying is the case - there was likely lots of the world not consumed by fire, in which instead plants died over time because the soil was acidified by acid rain, because of excess UV (even if you think that was more immediate and short lived than the experts say), knocked down by waves and earthquakes, and killed off by lack of sunlight for some number of years. Niches for tree living creatures, and well for major food networks, went relatively poof. Leaving behind, as you say, an abundance of (organic) substrate from dead plants and animals, which fed fungi, worms, and some insects. Also some seeds. Those animals left behind that had previously specialized in those fungi, worms, and insects, or who were generalist and small enough enough to adapt to them, survived global winter. The rest did not.
(In fact it seems that all current placental mammals have an insectivore ancestor that survived global winter: Shrewdinger.)
But then you think there would be nothing to compost? No organic material to collect and to use as the base of an agriculture of fungi and worms and insects? Huh???
Also I think I understand composting differently than you do. Organic material plus naturally occurring bacteria plus some water generates heat and humus. Which is a great food for large scale worm farms and creates a base for farming when the sun again shines. Organic material also feeds insects grown as food as well. No other energy inputs needs. It is releasing the energy stored in the organic material, using it for growth and excess heat. Ultimate source sunlight from years back but proximate source oganic material “in abundance.”
And we have gotten to a repetitious point so barring some new material added I’m done now.
Out of my arse, apparently. You’re partly right, the effects could hang around for years, I was wrong there. But by “an immediate effect”, I mean it’s a direct result of the impact - the Cl and Br volatilized by the impact itself. The depletion occurs in days & weeks after, not years. See here, for instance.
How familiar are you with what the world looked like at the K-Pg boundary?
Seaways reached up into the heart of continents that are nowhere near modern coasts. I’ve already cited the Tanis site. No doubt similar scenes of devastation occurred around the other seaways too. There was just a lot more coastline around then.
Not as an ongoing concern, no. The fungal abundance layer shows a spike only.
…until the organic matter is used up
…years later…
I think you misunderstood me - the organic matter you have to constantly feed into the system is the energy I mean.
“Abundant” doesn’t mean “usable for years.” That’s definitely not how composting works. You think all the wild fungi and bacteria are just going to leave all the organic material alone until you add it to your compost heap?
Moderator Note
People seem to be getting a bit testy here. Let’s remember to stay civil in GQ.
Colibri
General Questions Moderator
Yeah I I have no self-control but I do I appreciate that map, and no, I was ignorant of how much coastline there was, compared to now! That said, even with that much coast line, using the Tamis site as the standard, the source you cited states it flooded
Several miles inland even of the greater amount of coastline is still not much of the landmass. Might not even take out complete metro areas now!
To further reduce my ignorance - was there just very little water locked up in ice at that time?
Yes. I’ve read different estimates for the length of impact winter, from 18 months to 18 years, complete recovery maybe even several decades, but most settle into several years. During that time it is COLD. Which leads to this:
Scattered frozen plant and animal biomass lasting several years, even a decade or more, without rotting until chipped up, wet down, and added into compost piles? Yes, I think that. Heck I’ve had cordwood piled up in my yard for longer than that through all seasons!
Meanwhile a few recent models to share.
Bolding mine.
So back to humanity with some period of time to prep being able to have some number survive through impact winter with knowledge and know how enough to rebuild from some smaller numbers?
Biomass abundance. Fungi, worms, insects, able to be farmed even in very low light. Not sure but I think crickets and mealworms are decent for most vitamins.
Would not be a fun time post apocalyptic. But impossible? No.
Yes, in the late Cretaceous there was a lot less ice, and higher sea levels overall.
So, these surviving humans of yours, they actually live in the areas covered by the ice sheets, now? And they’re sending out teams of people to gather up frozen biomass so they can grow cockroaches?
This isn’t a plausible projection, anymore. This is Snowpiecer - But There’s No Train. The Icelandic airship engineers were a better just-so story.
Look, this is going to be my last post, because this thread has clearly gone off the rails (no pun intended). But you’re postulating way-out-there dystopian sci-fi scenarios when the simple fact is - last time, nothing man-sized survived, and humans have not shown themselves capable of working together and solving this kind of crisis in the way you’re suggesting.
Any scenario that postulates that ingenuity, co-operation and technology is going to save us is a non-starter. We’re not an entire species of Doc Savages, we’re the species that overpopulates, overuses, pollutes and kills. Being faced with a bigger killer isn’t going to bring out our Heinleinian competent man, it’s going to break down the thin veneer we’ve pasted on top of all that human stupidity and greed that makes for a sixth extinction, a Pacific garbage patch, a Holocaust, and anthropogenic climate change. We’re locusts, and all the grass just died.
And more time to prep makes it worse, because that’s when politics rather than chance comes into play. And the “survivors” who float to the top in that scenario aren’t the cream.
Even if the increased UV starts immediately, increased UV is inherently a longer-term concern. Unfiltered UV, whatever the cause, kills gradually.
Fascinating analysis. Thanks!
For stuff like cancers, sure. For some of the plant effects, like photosynthesis inhibition and affects on other pathways like nitrogen fixing, it’s a more immediate effect. Which, yes, will worsen over time, but everything I’ve read is about negative effects after just hours of exposure.
Not sure how you got from multiple years of quite cold with abundant deceased biomass in widely distributed cold storage to tundra or Snowpiercer, but yes I would see people gathering up biomass to use as an energy source and feedstock for an adaptive agriculture.
Well I think we agree that there was no one standing with a measuring stick saying must be under this size to pass through impact winter. Size was correlated with characteristics, inclusive of being generalist enough or specialized in the right things.
But yeah the key thing is our different impressions of our species. We have actually spread out across the globe to environments we are physically poorly adapted for precisely because we have been able to work together in groups and across multiple generations with the trick of culture and group knowledge to degrees that other animals do not come close to. I suspect individual whales have more brain processing power than we do, but we do that cultural and technological advancement thing better. Of course we do bad things with that tool of working together as well.
If we fail the at the task of working together to solve crises though we don’t need to wait for an asteroid to destroy us. Again, the potentially existential crises that we are faced with NOW, climate change among the top but not the only, will do us in well before that. OTOH if we can work together enough to survive the current crises, then collecting biomass and growing fungi, worms, and insects for food, even recycling out of the detritus and building new technologies, will be relatively a low bar.