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Would it be possible to detect an industrial civilization in geological record?

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Re: Would it be possible to detect an industrial civilization in geological record?

#171

Post by ncmncm »

Retric wrote: post #147
bufferoverflow wrote: post #101

Earlier quoted context omitted.

Oil is overwhelmingly used by burning it and its products. Only 4% of it goes to plastic production.

It’s not just plastic but also Asphalt, Lubricants, Fertilizer, etc. However, let’s assume they only used 10% as much oil as us and only used oil for ~100 years before dying off. They would still have started with easily extracted sources not offshore oil or ultra deep oil. The world had very easily extracted oil when we started. Further, there is no missing oil based on geology.

Oh, you have checked? There have been no dry wells?

I wonder where the term "dry well" came from.

Re: Would it be possible to detect an industrial civilization in geological record?

#172

Post by Retric »

ncmncm wrote: post #171
Retric wrote: post #147

Earlier quoted context omitted.

It’s not just plastic but also Asphalt, Lubricants, Fertilizer, etc. However, let’s assume they only used 10% as much oil as us and only used oil for ~100 years before dying off. They would still have started with easily extracted sources not offshore oil or ultra deep oil. The world had very easily extracted oil when we started. Further, there is no missing oil based on geology.

Oh, you have checked? There have been no dry wells? I wonder where the term "dry well" came from.

Most dry wells are around oil fields. We have fairly good understanding about the overall geology of oil fields, but you can have a dry well 50m from an active well. What we don’t have is most expected oil fields without oil.

Re: Would it be possible to detect an industrial civilization in geological record?

#173

Post by 8bitsrule »

ardit33 wrote: post #132
8bitsrule wrote: post #129

There have been many civilizations on Earth, maybe not many were industrial (ancient Egypt was clearly semi-industrial so far as lithic tooling is concerned.) We haven't looked deep enough very much. Many of the 10-25,000 year sites are buried dozens of feet underground. If there are any previous ruins, they're probably a hundred-or-more feet down. Seaside ruins from 10k+ years ago are now under 400 feet of water and…

ok... i get your point, but the major counterpoint: as earth / plate tectonic move around, underneath earth is constantly surfaced... from dinosaur fragments, to Cambrian era mollusks found in top of mountains (due to earth's crust movement). If there was a previous 'intelligent' civilization previous to us, they would have altered their environment to be detectable to us even today.

OK then let's find it. We're not really looking. Maybe it is indeed detectable, and maybe it will be hard. Maybe it's already staring us in the face, and our ideas about it are -wrong-.

We -believed- the Clovis story. Until some people -looked harder-. Plate tectonics ... laughed at. Until some people -looked harder-. Absence of evidence is not evidence of absence.

Re: Would it be possible to detect an industrial civilization in geological record?

#174

Post by mcguire »

ChuckMcM wrote: post #47
mcguire wrote: post #30

Earlier quoted context omitted.

The oldest known iron artifacts, ca 3200BCE: https://ars.els-cdn.com/content/image/1-s2.0-S03054403130020... https://www.sciencedirect.com/science/article/pii/S030544031...

I wonder how it is that the iron in meteorites doesn't just dissolve away. Any thoughts on that?

Those fell in a desert and were then made into jewelry and preserved in some of the best conditions on the planet. And they still look corroded.

Re: Would it be possible to detect an industrial civilization in geological record?

#175

Post by mcguire »

analyte123 wrote: post #71
ChuckMcM wrote: post #65

Earlier quoted context omitted.

I don't think so, meteoric iron (according to the wonderful blog series[1]) is early Egyptian. Iron (and steel) is stable outside the presence of oxygen and water. It doesn't just dissolve. And certainly if it were part of the steel reinforcement inside concrete in a building where special measures had been taken to insure that neither oxygen nor water would come in contact with it (as modern skyscrapers do) would pe…

What about when the skyscraper’s pieces are submerged under saltwater for a million years? Or are covered up by a mile of river sediment and then plunged another 5 miles under the earth for several million years?

Or the concrete develops cracks, allowing water into the steel reinforcement, which expands, further cracking the concrete until it collapses. Like modern bridges.

Re: Would it be possible to detect an industrial civilization in geological record?

#176

Post by ChuckMcM »

mcguire wrote: post #174
ChuckMcM wrote: post #47

Earlier quoted context omitted.

I wonder how it is that the iron in meteorites doesn't just dissolve away. Any thoughts on that?

Those fell in a desert and were then made into jewelry and preserved in some of the best conditions on the planet. And they still look corroded.

At this point I've sort of lost track of the argument. I read articles about how glaciers preserved soft tissue from the ice age (> 22 kiloyears ago)[1], I've got a bit of rock with a perfectly preserved trilobyte from Montana that is over 380 million years old, and yet people reading want to argue in this thread that massive amounts of inorganic structures built by humans to last for centuries will somehow be dissolved/eroded beyond detection in some short period of time.

So it seems unequivocal to me that human impact on the planet will be preserved for millions of years via the same mechanisms that have preserved snapshots of what was going on millions of years ago.

[1] https://www.cnn.com/2020/09/14/europe/preserved-cave-bear-sc...

Re: Would it be possible to detect an industrial civilization in geological record?

#177

Post by pmayrgundter »

samatman wrote: post #96
ancientworldnow wrote: post #68

Earlier quoted context omitted.

The earth is warming at a rate of four Hiroshima bombs per second [1] primarily because of human actions. I haven't read your document but it sounds like you're grossly underestimating our energy output. [1] https://archive.thinkprogress.org/earths-rate-of-global-warm...

Regarding Toba, Le Wik has this to say: The erupted mass was, at the very least, 12 times greater than that of the largest volcanic eruption in recent history, the 1815 eruption of Mount Tambora in Indonesia, which caused the 1816 "Year Without a Summer" in the Northern Hemisphere.[8] Toba's erupted mass deposited an ash layer of about 15 centimetres (5.9 in) thick over the whole of South Asia. A blanket of volcanic…

I spent some more time on this and now have a comparison table, with citations in my doc. V8 volcanoes still look more energetic and happen once every million years. @ancientworldnow, I'd note that the figure of 4 Hiroshimas/second is the measure of Global Warming, not of human energy production. Hansen acknowledges this in the linked TED talk from your citation, at about 7 minutes in ("it's about 20 times greater than all the energy used by humanity"). To get a sense of comparison, I also found that is the total energy released by a hurricane (note, ~99% hurricane energy is released in evaporation, the kinetic is ~1%):

Mt. Toba 74kya, VEI 8/M8.8 eruption energy: 1e21-1e22 Joules

Global Warming: 7.88e21 Joules/year

A hurricane: 1e21 J

Hiawatha Crater impact energy: 3e21 J

Human energy production 2013: 5.7e20 J/year

Mt. Tambora 1815, VEI 7 eruption energy: 1.3e20 J

Largest earthquakes 2: 1e19 J

Mt. Pinatubo 1991, Krakatoa 1883; VEI 6 eruption energy: 8.3e17 J

Mt. St. Helens 1980, VEI 4 eruption energy: 1e17 J

World nuclear weapon stockpile yield (estimate 2, extrapolated from USA): ~1e16 J

United States nuclear weapon stockpile yield 2020: 1.37e15 J

M8 Volcanoes once every million years, but M7 yield > 10x more energy over time:

“Analysis of this dataset indicates that eruptions of size M8 and larger have occurred with minimum frequency of 1.4 events/Ma… While the effect of any individual M8 or larger eruption is considerable, the time-averaged impact (i.e., erupted mass*frequency) of the very largest eruptions is small, due to their rarity. The long-term, time-averaged erupted mass flux from magnitude 8 and 9 eruptions is ~10–100 times less than for M7 eruptions; the time-averaged mass eruption rate from M7 eruptions is 9,500 kg s1, whereas for M8 and M9 eruptions it is ~70– 1,000 kg s1. Comparison of the energy release by volcanic eruptions with that due to asteroid impacts suggests that on timescales of <100,000 years, explosive volcanic eruptions are considerably more frequent than impacts of similar energy yield. This has important implications for understanding the risk of extreme events.” - Mason et al2

Re: Would it be possible to detect an industrial civilization in geological record?

#178

Post by pmayrgundter »

ncmncm wrote: post #54
pmayrgundter wrote: post #43

Earlier quoted context omitted.

I strongly agree with this take. I've been working on a paper comparing the effects of the Anthropocene to mega catastrophes in the geologically recent past. In addition to the Younger Dryas Impact (12kya), there's the Oruani (26kya) and Mt Toba (77kya) eruptions. From my calculations, it seems the climate change from each of these dwarfs any actions humans are currently capable of, namely petrocarbon burning and als…

Previous catastrophes did not vent the millions of tons of hydrofluorocarbons into the atmosphere that we will, that break down into a greenhouse gas thousands of times as potent as CO2. (We thought switching from CFCs to HFCs would save us. Joke's on us!) The total of HFCs currently in circulation, eventually leaked or vented, will produce as much greenhouse effect as all the CO2 currently in the atmosphere. (A shar…

It's not clear to me that volcanoes don't release both CFCs and HFCs. Do you have a citation?

I'm looking at the wiki articles, and then at the related chem articles about HFC types and synthesis. I'm not a chemist, but a quick look around makes me think the known CFC, fluorocarbon and halomethanes in volcanic gases would suggest the same or similar compounds as in our engineering uses.

https://en.wikipedia.org/wiki/Volcanic_gas#Composition https://en.wikipedia.org/wiki/Halomethane https://en.wikipedia.org/wiki/Hydrofluorocarbon

On Hiawatha, agreed it's not yet dated, though it is recent: "The age of the crater is presently unknown, but an impact sometime during the Pleistocene is consistent with presently available geological and geophysical data." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/

They also raise the possibility that some of the radar returns indicate it's still hot in the center of the impact area(!). If so, it's probably one of the YDB impactors.

Btw, there's been another one discovered near it: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL07.... They say they don't think it's related, though it does still have large features that should have been eroded away if it were really old. We'll see!

Re: Would it be possible to detect an industrial civilization in geological record?

#179

Post by jula432vdf »

filoeleven wrote: post #123

One of my favorite quotes from Iain M. banks’ Culture series, paraphrased here since I don’t recall which book it’s in, is that technological progress is more like scaling a rock face than climbing a ladder. There is so much room for surprise and incomprehension. I sometimes think about how vast the parameter space of our physical universe is, and if that vastness means we wouldn’t be able to recognize ancient advanc…

As far as we know, quasars could be fully artificial, and around them you could find some of our future friends.

and those things would be pretty outdated - ancient - technology by time we spotted them.

Re: Would it be possible to detect an industrial civilization in geological record?

#180

Post by ncmncm »

TeMPOraL wrote: post #142
nraynaud wrote: post #60

Earlier quoted context omitted.

Wouldn’t any constant force tend to ellipticize the orbit and lead to a return to earth?

Would have to do the math to be sure, but doing some quick simulations in my mind - I believe you're correct, modulo the impact of the orientation of that force changing (Earth goes around the Sun). Let me illustrate with a diagram: PROGRADE (raise apo) | +--------------+--------------+ | | | -> --->--- -> | +- -> -/ \- -> -+ -> / \ -> / -> / /II\ \ | -+ +----+ -> | |IIII| | | +- IN SHADOW | \ -> \ \II/ / | -+ | -> \…

It would only be eclipsed, daily, during a small part of each half-year, no? And, on alternating sides of its orbit.

Usually people blame the moon, and three-body dynamics, for disrupting other Earth orbits.

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