Surviving a meteorite strike - a research proposal

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beezaur

Joined
Jul 31, 2002
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No, I'm not turning into Chicken Little. But I do pay attention to astronomy, e.g. http://www.spaceweather.com/ , and all this Earth impact stuff has started the hobby-survivalist in me thinking.

Suppose, for the sake of argument, that a big rock does hit Earth. Say the impact leaves a crater 75 miles wide and a devastated zone 5 times larger. Atmospheric debris would have largely settled after a year, but climate would be very screwed up: temps lower by 30 deg F, wrecked ocean chemistry, drastically changed weather patterns. Maybe this straightens out in 10 years, but meanwhile most land plants die. Along with them goes dependent animal life, namely us.

The problem is pretty simple for that first year: you have to stay dry, warm, and fed with your own resources. After that the sun should more or less shine through, and the problem becomes rebuilding sustainable resources.

I am a civil engineering student (structural) and would like to propose a research project along these lines. The specific idea is to develop strategies for a family-sized group to survive a major natural catastrophe like a meteorite strike. My own research goal is to develop designs for affordable and highly survivable dwellings. I don't think my school would let me do my master's thesis on something so outlandish, but I do think the chances are good for getting a paper or series of papers/articles published somewhere.

I am very interested to hear anyone's thoughts, and welcome anyone who would be interested to help. Efforts need not be in the structural field or technically oriented, but should be more than mere speculation. Food, water, defence, and many other areas could be addressed separately or combined.

I have been working on my own for over a year and anticipate work continuing for another 2 or 3. Even if nothing substantial comes of this, it should be an interesting diversion.

Scott
beezaur@myhome.net
 
my first thought is the dewlling should be partially/fully submerged, both to allow it to be built out of the way of current normal life and also to take advantage of the earths insulating power.

does this raise questins ont he defensibility of the structure though? it would definately have to be defensible as there would be alot of looting as people starved to death and if it looked like you were in a place full of food and other supplies you would be a prime target

maybe thats another reason for it being submerged, rather than building a fortress thats defensible build a burrow that is hidden so you dont need to defend it?

burrows are certainly defensible and good for survival anyway (one of the lessons of the vietnam war...)
would you take into account location? what if the asteroid hit the polar ice cap? any low lying structure isnt much use unless its on the side of a hill if the ice cap melts and sea levels rise several tens of metres
 
Bee,

Some serious astronomers have been talking about earth being struck for years. It's only been recently that the mainstream media has caught on.

Considering earth's history, it's not a question of IF we will be hit again .......... but when (and where).

Brent...
:p
 
Yes, I agree with the earth-sheltered design. In fact, that is one of my motivations - my wife and I are actually planning to build one one when I get out of school.

The design so far is reinforced concrete with tilt-up construction, about 3000 square feet and 10 ft high floor to roof slab. The roof will be about ground level and covered by ~3ft of soil. Earthquake design is for 1/2 g, a real big jolt. The funny thing is the cost - about half what a comparable wood home would cost.

They are kind of "industrial", but earth-sheltered homes make a lot of practical sense.


Scott
 
earth sheltered but i dont think three feet is enough, i think that the frost line in anchorage alaska is much deeper. maybe eight to ten feet. would use foam insulation over the concrete to add r-factor. would agree with earthquake resistant design. would like to build near a self sufficient gas well so that it would give you a lot of options for energy availability. a natural gas well would allow you to heat and provide electricity for your home, power your well pump, and create a more normal existance. also let you run your septic system. this would let you raise some food underground and allow for long term selfsufficiency. now that you have the energy problem licked you can look at how much space you will need to house your generator, food stocks, vehicles, fuel for the vehicles, and room for the people you wish to enclude in your shelter. thus you could plan the size and layout of your earth shelter.

just some food for thought,

alex
 
"maybe eight to ten feet. would use foam insulation over the concrete to add r-factor. . . ."

That's easily doable. One reason I'd like to publish something is that such structural design is actually pretty simple, but information is scarce. Depending on wall spacing and a few other variables, your roof load dictates a slab thickness on the order of 8-10 inches.

Imagine being in Alaska in January and the power goes out. No huge deal if you are covered by 10 feet of soil - your indoor temperature never falls below, say, 40 deg F, depending on latitude. The Earth heats you from below.

Scott
 
I'd think you would want to include some form of wind powered generator system for electrical needs. Of course, discreet no longer fits....
 
I'd start out by clearly laying out your requirements, before leaping ahead to the design stage.
 
Sorry for not being clear. The general requirement is for a family-size group to survive the aftereffects of a major meteorite impact (or any catastrophic ntural disaster) by any means possible. This means addressing food, water, medical, and any other needs through means such as growing food in a greenhouse, power generation, and other such things.

As for my particular focus, the dwelling, the requirements are to maintain capabilities for:

- water treatment/storage facilities
- crop growing
- heating
- structural integrity for earthquakes
- energy efficiency
- temporary group shelter
- communications
- repair of various equipment

I'm not really "leaping ahead" with anything. In fact, the last 18 months have been mostly research - finding out what others have done, learning structural design, etc. At this point, I have several preliminary designs, complete with rebar and concrete figures, construction methods, even approximate schedules.

The parts that lie ahead are the interesting ones: incorporating good ideas like windmills and gas. Besides, there really isn't any reason to not forge ahead. If an idea doesn't pan out, scrap it. Usually other good ideas are discovered in the process of eleminating bad ones.

the timeline is pretty flexible and generous. Should anyone decide they are interested to help, 24-36 months is plenty of time to go from zero to designing complicated concrete structural members (or power generating plants or defense plans or greenhouses or ...)

Scott
 
I mean *very specific* requirements, that you can design to:

<li> water treatment/storage facilities - how much storage capacity needed? Expected water consumption rates. Treatment - what sort is necessary - what are you treating/filtering the water for?

<li> crop growing - required yields? Expected consumption rates? Nutrients required from crops? Crop selection? Crop growing requirements - water, fertilizer, sunlight, pest control, ...

<li> heating - temperature ranges? Allowable energy consumption? ...

<li> structural integrity for earthquakes - how severe? how frequent?

Etc.

Other things to think about might include siting requirements (to avoid coastal tsunamis, earthquakes, flooding). Expected size of impactor, and allowable distance from point of impact?

I find that by carefully analyzing the requirements, you save a fortune in the design and implementation stages. If you're already leaping to implementation techniques before you've dealt with the requirements, you're ahead of yourself.
 
a couple more points:

1) putting the shelter 10 feet below rather than 3 feet is a great idea as it would make it considerably more effective in the case of a nuclear war

2) in the event of a nuclear war more careful consideration must be given to water supplies and air filtration and food sources/storage (eg salty foods absorb more radiation etc)
 
Not to sound too terribly pessimistic, but the dust cloud formed by one of these "respectable" strikes would overtake any nuclear explosion, and toss enough dust into the atmosphere that I doubt that even with survival gear (read: food & water), we would last long enough for it to get back to a state that we could actually sustain our lives. The complete darkness would practically wipe out all plants, starving land animals (and evntually killing all of them), take out most of the sea creatures (many sea creature depends on planktons, which does rely on the sun), and the only ones we've left with are the creature that depend on the chemosynthesis deep near the deep sea vents. I doubt we could actually fish those creature down there at such a depth easily to sustain life.
Yes, meteor strikes are a "when" event, but I sure hope it won't happen in my life time.
 
beezaur, this is a very interesting topic indeed. Your space requirements would be great. There was a movie made not too long ago with Brendon Fraser about an underground dwelling that his parents built. You may want to take a look at the movie, dang, I forget the title...perhaps someone else will remember. They cover all the aspects you mentioned for a nuclear holocaust, which I would imagine, would pail into comparison with an ELE such as you describe. (Extinction Level Event).

Anything that leaves a crater 75 miles in diameter will have devastated and wiped out the entire planet IMO. I do not believe that anything could survive such an event. You would have to be very deep in the bowels of the earth to escape this. I think it would make any underground dwelling prohibitively expensive. Our only other alternative IMHO would be a space colony.

Your project, nevertheless is of great interest and I would love to be kept updated as to your progress. Unfortunately I am not at all technically inclined.
 
ThorTso,

The movie was "Blast From the Past", Here is a link:

http://www.blastmovie.com/

Atmospheric debris would have largely settled after a year, but climate would be very screwed up: temps lower by 30 deg F, wrecked ocean chemistry, drastically changed weather patterns. Maybe this straightens out in 10 years, but meanwhile most land plants die. Along with them goes dependent animal life, namely us.
Click to expand...

beezaur,
You have picked a very ambitious project for yourself. It would be far easier to figure out how to establish a completely self sustaining space colony on Mars than to take on the kind of disaster you are describing. Either way you would need an entirely self contained eco-system on a scale large enough to maintain a viable gene-pool indefinitely; only, there you would have a given set of environmental conditions; whereas here you would start with an entirely and unpredictable set of challanges.

Somethings are just not worth surviving, and what you are describing is one of them.

n2s
 
I have studied similar situation, that of tornado and fall-out shelters. However there the scenario is usually just to stay alive
for 2-4 weeks in the shelter at most. An underground room of reinforced concrete is an excellent idea for a variety of survival situations. Personally I would not want to live underground, but building a cellar/shelter underground makes sense. One thing to keep in mind is to ensure as much as possible that if you go in, you can get out again. This means design, as well as tool storage. Another is to ensure at least a minimum amount of natural ventilation. The longer you plan to stay down, the more you have to prepare for. And then of course waste disposal has to be planned for. Most scenarios never worry about water for more than 2 weeks, as they assume w/in 2 weeks you can leave and forage for more.
 
Originally posted by not2sharp
Either way you would need an entirely self contained eco-system
Click to expand...

Not necessarily - it all depends on the size of the event he is planning for. (Part of the requirements/specifications I'm pestering him for.)

If it's not a shatter-the-earth-and-blow-off-the-atmosphere level event, he has the opportunity to import resources from outside his shelter - air, water, energy, and raw materials. He doesn't have to be completely self-contained.

As to genetic diversity - if he intends to repopulate the human race just from the contents of his shelter, that's going to be tricky. If he's assuming significant levels of survivors in other areas, that's simpler. It all depends on the size of the rock, how fast it's going, and where it hits.

Some research into the seeds stored is in order, too. You don't just want to buy seed corn at the local feed store...
 
With a home that is 10 feet underground, how do you build an entrance? Also, how would you ventilate and/or purify the air supply?

One more thought...what if you hit the water table when digging? What additional problems or features are possible when water is factored into the picture?
 
Originally posted by bae
I mean *very specific* requirements, that you can design to: ...


I find that by carefully analyzing the requirements, you save a fortune in the design and implementation stages. If you're already leaping to implementation techniques before you've dealt with the requirements, you're ahead of yourself.
Click to expand...

bae,

No offense, but I think you misunderstand the engineering design process. Often times, there simply is no way to prescribe an extremely specific set of requirements and then grab *the* design meant for that purpose. There is literally no way to go from "nothing" to "finished product" without some trial and error.

Your second point, saving expense in implimentation, is a very good one. That's the entire point to my *research* proposal. My efforts are a hobby, by the way. There is no expense or fortune to be saved.

Third, I don't think we are defining "implimentation" in the same way. In the engineering community, that word means you are actually building the result of your plan. As far as "leaping into" implimentation techniques, how else does one design? You have to develop the implimentation techniques ahead of time, before you actually do the implimenting. Imagine ordering 10 trucks of concrete one day, and then realizing your formwork is inadequate, or that you can't pour that much concrete without developing gigantic cracks in your structure.

Here's an example that I am working on currently:

Q: How can a family survive in the dwelling with no outside resources for 1 year given year-round freezing temps and little to no direct sunlight?

In getting to "A," you have to do a study of how various designs perform. There is no established method. You have to invent things like manual methods for your existing well, determine how much food is required and how to best prepare meals. What does the structure do thermally for that year? You really have to make up the rules as you go.

Also please keep in mind that it is impossible to state all my work to date on this board. For example, the earthquake loading I have worked with is this:

Given: 3000 sf reinforced concrete structure, 10 ft floor to roof. Soil cover over roof is 3 ft at 130 pcf, neglect shear strength.

Loading (earthquake):
- 0.5 g in any direction
- frequency 0.25 to 2 Hz
- wavetypes P, S, R, L
- duration adequate to fully develop dynamics

Required:
Design a structure that meets Givens and needs no repairs after loading.

Sounds like "requirements before design," right? Not so - even the loading is something that was developed with feedback from strengths of structures.

Here again, there is trial and error. First you load the structure with a steady 0.5 g load. If it passes, you move to the next loading. If not, redesign and reload. Keep doing that until you run out of loads. You don't start with a finished product that magically makes it through all phases.

Construction methods are intimately tied to strength. For example, I am using tilt-up wall panels, so the joints are different from the poured-in-place joints that I used previously. You have to try things or you don't know if it will work.

I can write many pages on just this one problem, but it's an overly specific thing to post here. If you really want to get into the nitty gritty, email me.

Scott
 
Originally posted by beezaur
No offense, but I think you misunderstand the engineering design process.
Click to expand...

Umm, no I don't. Until I retired, I was the director of engineering for an S&P 500 company, in charge of hugely complex multi-year-long development projects, and think I may have a firm grasp on the process. (These words you read are coming to you through equipment, software, and protocols I designed, for instance...)

You usually come up with your requirements and specifications first (and there *is* an important role for research in this step), *then* move on to design/implement. There are dozens of different development models that work, of course, but most of them involve focusing on your requirements as early as possible. (And the most successful, in my mind, involve stepwise refinement of your requirements/design/implementation through prototyping, etc.)

So I'm curious what your specific requirements are for this shelter, for if we had those, we could start throwing out ideas. Not knowing that, though, I suspect we won't be of much help.
 
bae,

You should read my first post again. The requirements are spelled out there. They are possibly not as specific as you would like because the events themselves are not well constrained. The luxury would be nice, but isn't possible.

I acually think we are talking about the same process of iteration. I consider it a research project instead of strictly a design project because the constraints are not well known. There is feedback between "what do you want to do" and "what can you do." The rules change based on what the capabilities are.

You said, "(And the most successful, in my mind, involve stepwise refinement of your requirements/design/implementation through prototyping, etc.) " I don't see how this differs from what I have been doing for over a year, with the exception that structures are too big and expensive to prototype. I think we are merely reading one another's posts poorly.

For your question about specific requirements, they are related to a meteorite impact as described earlier. As stated, the first year is to be survived with no outside resources. this means water, food, heat, and any other requirements will all have to be derived from internal means.

The means are often location specific. Rural dwellings would establish power for their well, or pull the pump and rig a manual system. Large volume storage is also an option if a well is not available. The purpose of the research is to develop strategies for a variety of methods that can be assembled in a more or less modular manner. This way, dwellings in differing geographic settings can achieve the same level of preparedness.

The design goal is not to design a specific thing like a water tank. It is to establish the bounds for water tank design, i.e. what will work and what won't work. Specific design is trivial and to some extent pointless, because no two people will be able to (or want to) build the same structure or have the same food store.

Daniel's post is exactly the kind of input I am looking for. Entrances for deep structures: sounds like a tunnel. One could be made big enough for a vehicle or small like a mine shaft. The point is to evaluate the entrance in light of economcs, overall stategy, and what you want to live with when the big rock never comes.

Air: theoretically you can filter air through moist soil and drive the flow with thermal gradients (hot air rises). This is an unexplored area that needs development.

Excavating below water table: you can drian the soil and collect the water, or build a waterproof foundation. Waterproof foundations are expensive, and colloecting can be complicated. An interesting subject is: how far would the water table drop if it doesn't rain for 5 years. How would one collect water in that case?

These are all criteria that are important to some people but not to others, important in some regions but not others. There are just too many variables to apply any one design to a specific site. A good design is flexible enough to satisfy different requirements as they come up in an ill-defined situation. That's the goal here.

Scott
 
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