# Is there a similar disaster that can help me determine survival rates?

Short version: 1 million people were left to fend for themselves (a.k.a. there's no room at the inn scenario) through what amounts to a storm of asteroid fragments pulverizing the United States (largest being 4km and scaling down from there) as well as the ensuing impact winter.

Are there statistics available for similar disasters that can help me determine the following?:

• What percentage would die from asteroid impacts (direct, air blast, thermal, etc)?
• What percentage would die from lack of resources (food/water/medical treatment)?
• What percentage would die from anarchy violence over resources?
• How many would be left to attempt attacks on the standing bunkers & shelters?

Thanks!

**Editing to clarify: I apologize for not being more clear.

1. I am not referring to separate asteroids. The key word in my scenario is "fragments." These are pieces of a much larger asteroid which we attempted to divert but instead accidentally blew up (or some similar OOPS), so the pieces are now raining down upon us.

2. Instead of "similar disaster" I probably should have said "similar disasters." I'm thinking of combining statistics from, say the worst faminine in history or the effects of a nuclear bomb (minus the fallout radiation deaths) or the collapse of a major country's government leading to anarchy violence. So I'm looking for something like: "The ____ famine wiped out ____% of its _____ population." or "_____ people were killed in the violence following collapse of _____ government." I can do my own research, just looking for names of events to hunt down.

• "similar disaster" - I seriously doubt it. – Mołot Aug 25 '16 at 9:38
• I very strongly recommend that you check out Meteorites in the United States. The data doesn't cover the last few years, but that's largely irrelevant here. Notable is that the most common size of a meteorite is 4-8 kg, with a fairly even distribution around that mark, and without having run the numbers, I'd estimate that about 3/5 of all meteorites that fall in the US are 8 kg or less. You are looking at a few dozen meteorites at most, over some 200 years or so, which might meet your criteria for size. Far less than one per year! – a CVn Aug 25 '16 at 11:15
• Note that "size" is not the same thing as "mass". You specify size, whereas that page specifies mass. – a CVn Aug 25 '16 at 11:16
• Thank you for your comments! I can see that I have not been clear enough in my initial post and have now hopefully corrected that mistake. – K.M.B. Aug 25 '16 at 17:47

The four links are entry points into events that could be similar to a massive occurrence of strikes. They are provide in site into large scale events and related effects. Especially Mt. Tambora another not linked was Krakatoa. These are only entry points on these events I am sure other links may yield greater details on effects. I know there are books that cover these and provide statistical data, but can not confirm those been transited to the internet.
You will find the year with out summer is a major effect of tons of material thrown into the atmosphere. And the resulting disease, death and famine

Tusunga event

Arizona info

YEAR WITH OUT SUMMER Mt. Tambora

Mt. Tambora

• Thank you so much! I have heard of the Tusunga event, but I hadn't come across the link you gave. Those descriptions and paintings are fantastic! :) I'm looking forward to following the other links and suggestions you gave! :) Exactly what I was looking for. – K.M.B. Aug 26 '16 at 0:20

Well there are some tools that can aid in our estimations:

From these site's there will need to be a bit more information, things like impact angle, asteroid density, velocity, and where the asteroid/s hit.

What percentage would die from asteroid impacts: Depends where they land, a slightly dense 4km asteroid at low velocity leaves a 22.5 km impact crater (on land), and an 8.5 magnitude earthquake that would cause significant damage within a 50km radius of the impact site. The air-blast would max at 4 500kph at a pressure of 26bars. The site seems to have calcuated the air blast at 50km away from the impact (taking 2.5mins to arive). Ejecta would be mostly dust and some fragments at 50km away. So if the 1million left are widely dispersed, deaths from direct impact would have little effect.

What percentage would die from lack of resources: Again, depends where they land. Widespread destruction means widespread damage to agriculture, and water sources. The asteroid that landed 65m years ago killed 3/4 of all life on Earth. You should be able to estimate from there, but probably in the realm of 50-60%.
Edit: Found a nice article on the Barringer Crater that spicetraders mentioned. A 30 to 50m iron meteor would've destroyed and damaged vegetation 1000-2000km$^2$ around the crater.

What percentage would die from anarchy violence over resources: Looking at hurricane Katrina and then the tsunami in Japan we see pretty stark contrasts in how people responded to disaster. Here I think you can use poetic license as you like. Some communities will respond better than others - so I'd say it depends on how you want your story to go.
Edit (for changes in the question): I'm not from the USA but it seems to me Katrina was one of the worst disasters to strike the US in recent times. This caused flooding and a general state of lawlessness. The violence that ensued seems to be debatable and the exact number of murder victims is unknown:

Would every city in the US react the same way, I doubt it. But there some interesting things to read there and then lots of space for contrasting reactions in your story.

How many would be left to attempt attacks on the standing bunkers & shelters: So yeah, depends again on how many were killed off above. Suppose 40% from direct impacts, 60% (of the 40% since you can't kill the dead) from lack of resources (360k still alive), and then lets lob off another 60% of what's left from immediate violence within a short time after the disaster before things settle. You'd be left with around 200k (216k to be exact) people.
Edit: I honestly don't think people would start tearing each other apart when we're social creatures by design that survive better in groups. But a paper here indicates that there is a spike in crime following natural disasters.

Play around with above sites I think, that will give you the best idea.

• Thank you for taking a thorough stab at answering my questions! Your answer regarding direct impact confirms my suspicions. I have trouble extrapolating from the K-T event because the asteroid was so much larger than what I'm envisioning & there is the added complication of the giant eruption muddying the scientific waters. I will definitely follow up with more research on the Katrina and Japanese Tsunami events. I appreciate your pointing out the difference in social responses. Do you have any reference for the 60% lost to violence or is that just a guess? – K.M.B. Aug 25 '16 at 18:13
• Fair enough, the K-T event did have other factors influencing mortality and the asteroid was going very fast. Sorry, it was a guess - I couldn't find any good examples. There was almost no violence in Japan, plenty from Katrina - which from what I could tell was largely race related. – Shaun K Aug 25 '16 at 23:19