Physicists Say This Is the Best Place to Hide Indoors From a Nuclear Shockwave

[TrappedinCalifornia]

Physicists Say This Is the Best Place to Hide Indoors From a Nuclear Shockwave

A new study provides a reality check about your chances of surviving a nuclear explosion. It suggests that, even if you’re hiding indoors and far away enough to avoid immediate disintegration, the high-speed winds created from the blast could still be enough to kill or seriously injure you. But the findings also indicate the best locations within a building to take shelter, should the worst-case scenario ever occur...

The team’s findings are published in the journal Physics of Fluids...

The worst places to hide seem to be in the direct vicinity of the windows, door openings, and hallways, since this is where the air will be most funneled through in the shockwave. But airspeeds are likely to be lowest in the room corners away from these openings along the walls facing the blast, so these areas should be the best to take immediate shelter. The researchers created a model showing where air velocity is likely to be highest inside a building...

And for those who were thinking 'kitchen'...

...For those of you who are wondering, the team did not look at what would happen if you tried to survive a nuclear blast by hiding inside a fridge, a la Indiana Jones, though other scientists have cast doubt on that particular piece of movie logic.

However, the old standby did toy with the right direction...

[Citizen_B]

While interesting, I'm not sure how much practical/actionable value this info may have. The first assumption is you're in the goldilocks region of close enough to get the damaging wind effects of a shockwave, but far enough away where the heat/shockwave doesn't obliterate your entire house. Then you have to be aware that the shockwave is coming before it arrives, which would be noticing the intense bright light and recognizing it as a nuclear explosion. And being able to notice that without going blind, which if one was blind and in pain, good luck rapidly finding a safe place to hunker down for the imminent shockwave. I suppose this info might be useful if a nuclear attack is expected/possible so one could consider it for a sleeping location.

[Epaphroditus]

Basement, root cellar or shelter ... everyone has an underground shelter, right?

[user120312]

Where I live, a relatively high air blast could be effective, else the canyon walls of a pretty narrow canyon plus copious old growth trees will likely absorb much of the wind/heat. A tree falling on the house could do the trick so that's a factor.

I'm developing a bunker behind the garage underneath my workshop that should be helpful. The floor should be just above the historic high water level of the creek which is about 20' away.

[KevinB]

Upon seeing the initial bright flash of a nuclear weapon, drop to the ground, place your head as far as you can get between your legs.......... and kiss your *** goodbye.

[TrappedinCalifornia]

Originally Posted by KevinB

Upon seeing the initial bright flash of a nuclear weapon, drop to the ground, place your head as far as you can get between your legs.......... and kiss your *** goodbye.

One is forced to wonder given that the report is only addressing the initial shockwave and not necessarily what follows...



But, that brings up the question often posted on this site...





It would seem to be, in theory at least, a relevant discussion... Top Russian official warns of ‘global tragedy’ if allies send Ukraine new weapons

...“If Washington and NATO supply weapons that would be used for striking peaceful cities and making attempts to seize our territory as they threaten to do, it would trigger a retaliation with more powerful weapons.”...

Dmitry Medvedev, the deputy head of Russia’s security council, said the meeting at the German air base “left no doubt that our enemies will try to exhaust or better destroy us,” while also admitting “they have enough weapons” to do that.

He said if the war, which began Feb. 24, 2022, drags on, it could lead to Russia forming a military alliance with “the nations that are fed up with the Americans and a pack of their castrated dogs.”

Medvedev, a former Russian president, warned last week nuclear war could follow if Russia loses the war to Ukraine.

The link in the above quote is to... Russia threatens nuclear war if it loses in Ukraine

Which is why, I suppose, it was posted this morning... 2023 'Doomsday Clock' announcement: What to know and expect...

Scientists will reveal on Tuesday how close humanity is to armageddon with its latest edition of the "Doomsday Clock."...

Tuesday's announcement will be the first since Russia's invasion of Ukraine, which could move the clock closer to "doomsday."...

Shortly after Russia invaded Ukraine, the Bulletin kept the clock at 100 seconds to midnight, saying that Russian President Vladimir Putin's threats to use nuclear weapons if NATO stepped in to help Ukraine "is what 100 seconds to midnight looks like."...

Oh well... Every few years, someone rediscovers that there are nuclear weapons out there. At which point, the political posturing, hand-wringing, machinations, et al. begins anew. Then again, maybe there's a reason and it goes back long before the advent of nuclear weapons. (Matthew 24 comes to mind.)

It seems to come under the heading of...

[Usmc0844spare]

Like preppers don't got enough to do without labeling their walls.

"Go here if flash is over there"

[GeeBee49]

I've always heard that Los Angeles is one of the top five cities for a nuclear attack. I live 16 miles from downtown so forget it.

[TrappedinCalifornia]

Originally Posted by GeeBee49

I've always heard that Los Angeles is one of the top five cities for a nuclear attack. I live 16 miles from downtown so forget it.

You might give NukeMap a try.

It's legitimate, put together by a Science professor and allows you to select various yields, air burst vs surface detonation, etc.

The site's been up for awhile, but it was bandied about a bit when Putin started 'threatening' nuclear war... Nuclear Bomb Blast Map Shows What Would Happen if One Detonated Near You

There are several YouTube videos...



The bottom line is...



There's no way to account for all the variables and, certainly, a primary target such as Los Angeles isn't going to get just one sent its way; potentially making the program more relevant to a terrorist attack. But, it's interesting.

[GeeBee49]

I know this thread is about surviving the initial blast/shockwave but I think anyone living near one of the target cities needs to consider the aftermath as well. Radiation poisoning from the fallout carries a death sentence of two days or two weeks and is a horrible way to die.
One comment that seems to always follow any discussion on nuclear war is that the living will envy the dead.

[squeeze]

Hey; what if the Chinese float a nuclear weapon on a balloon over the US? Cool idea huh? just a thought.

[TrappedinCalifornia]

Originally Posted by GeeBee49

I know this thread is about surviving the initial blast/shockwave but I think anyone living near one of the target cities needs to consider the aftermath as well. Radiation poisoning from the fallout carries a death sentence of two days or two weeks and is a horrible way to die.
One comment that seems to always follow any discussion on nuclear war is that the living will envy the dead.

Post #6 alluded to it in the 2nd video from The Day After.

The problem is that it's mostly theoretically; i.e., extrapolation from what happened after Hiroshima and Nagasaki coupled with guesswork. Some of it can also be extrapolated from nuclear tests and what happened at places such as Chernobyl and Fukushima. But, at the scale of WW "last" (use of nuclear weapons) and given the near-infinite variables, the simple fact is that nobody knows what the situation will be.

If you're interested, in 1986... Casualties Due to the Blast, Heat, and Radioactive Fallout from Various Hypothetical Nuclear Attacks on the United States

...An all-out nuclear war between the United States and the Soviet Union would destroy the urban areas of both countries and thereby the infrastructure that makes them modem industrial states. This fact makes the deliberate launching of such a war the ultimate act of folly. Nevertheless, military planners have felt that the United States should have "credible strategic nuclear options," and have worried about those credible nuclear options that the Soviets might devise. This concern led to debates in the 1970s over the possibility of "limited" nuclear wars that might produce significant military results but minimal civilian casualties. During this same period, according to Ball (1983; p. 19), U.S. policy was changed to exclude targeting "population per se"—presumably because "collateral" civilian casualties from the targeting of economic or military facilities were expected to be much lower than those from direct attacks on population centers. And recently, the Strategic Defense Initiative has provoked debates over whether strategic defenses could reduce U.S. casualties from an all-out nuclear attack to less than catastrophic levels.

How much would these options and policies actually buy in reduced casualties? Unfortunately, quantitative estimates of these reductions are hardly ever offered. Yet such estimates of casualties—and, just as important, the public disclosure of the assumptions behind them—are essential to the evaluation of these concepts.

In this paper, we describe the results of an exploration of the sensitivities of the estimates of direct casualties from limited nuclear attacks on the United States to various assumptions concerning the targets and the casualty models used. We have estimated the casualties from four different types of attacks: three involving approximately 100 targets each and the fourth a major counterforce attack on U.S. strategic-nuclear facilities...

Some of our results show clearly the enormous casualties that only 1 percent of the current Soviet strategic arsenal could inflict on the United States, even if the targets were military-industrial or strategic rather than population per se. We have also found that, as counterforce attacks become more comprehensive, the distinction (in terms of casualties) between "counterforce" and "counterpopulation" targeting becomes increasingly blurred. We expect to find similar results for U.S. counterforce attacks on the USSR.

These casualty estimates have a critical beating on the debate over the possibility of "limited nuclear options" as part of a strategic doctrine. Either superpower contemplating such an attack should be well aware of the fact that such attacks—even if limited to military targets—could cause casualties that approach those from all-out attacks. We emphasize this point especially because the significant underestimates in the published DOD casualty estimates for counterforce attacks suggest that U.S. policy concerning counterforce attacks is not fully realistic. Certainly this appeared to be the case during the recent debate of the "window of vulnerability" of U.S. ICBMs. Virtually no attention was given to the casualties that would result from an attack on U.S. missile silos.

Other work has shown that, even after such a devastating attack, either superpower would retain a residual capability to destroy the cities and economic infrastructure of the other many times over (e.g., Feiveson and von Hippel, 1983). And it seems likely that the other superpower—after suffering tens of millions of deaths—would launch at least as horrendous an attack in response. Therefore, the only conceivable rationale that theoretically could be used to justify a strategic counterforce attack would be the certainty that the other side had already committed itself to a major nuclear attack—a certainty that could not be achieved in the real world.

It is our hope that national decision makers will develop a better understanding of the "collateral" consequences of hypothetical first strikes and of the enormous destructive capacity of the weapons that would survive. That understanding should make them less likely to seek counterforce capabilities or to fear such attacks from the other side.

Remember, U.S. and Russian arsenals are only the beginning of any analysis as only 9 countries are currently recognized as having nuclear capabilities. The problem is that doesn't account for things such as dirty bombs and other 5th Column activities which would inevitably coincide with a nuclear exchange. That's without even taking into account the 'reactions' of any surviving populace.

Let's just say that an all-out, nuclear exchange isn't likely to leave much in terms of what can be exploited or those who could/would exploit it.

Of course, there's always...



Or, alternatively...



So... There's no reason to abandon all hope just yet.

[GeeBee49]

If I didn't live where I do I might have a more positive attitude but I don't worry about it. The nuclear weapons today are so much more powerful than the ones dropped on Japan that if even one gets through our defenses and strikes the LA area it will be over in a flash.
Like I said, I don't worry about it and never really think about it unless it comes up in conversation.

[GW]

I'm working on poses for when my shadow gets burned into a wall.

[TrappedinCalifornia]

Originally Posted by GW

I'm working on poses for when my shadow gets burned into a wall.

Well, many do think a man should leave something behind to show he'd been here...

[TrappedinCalifornia]

By the way, according to MIT... The Devastating Effects of Nuclear Weapons

...As the rapidly expanding fireball pushes into the surrounding air, it creates a blast wave consisting of an abrupt jump in air pressure. The blast wave moves outward initially at thousands of miles per hour but slows as it spreads. It carries about half the bomb’s explosive energy and is responsible for most of the physical destruction. Normal air pressure is about 15 pounds per square inch (psi). That means every square inch of your body or your house experiences a force of 15 pounds. You don’t usually feel that force, because air pressure is normally exerted equally in all directions, so the 15 pounds pushing a square inch of your body one way is counterbalanced by 15 pounds pushing the other way. What you do feel is overpressure, caused by a greater air pressure on one side of an object.

If you’ve ever tried to open a door against a strong wind, you’ve experienced overpressure. An overpressure of even 1/100 psi could make a door almost impossible to open. That’s because a door has lots of square inches — about 3,000 or more. So 1/100 psi adds up to a lot of pounds. The blast wave of a nuclear explosion may create overpressures of several psi many miles from the explosion site. Think about that! There are about 50,000 square inches in the front wall of a modest house — and that means 50,000 pounds or 25 tons of force even at 1 psi overpressure. Overpressures of 5 psi are enough to destroy most residential buildings. An overpressure of 10 psi collapses most factories and commercial buildings, and 20 psi will level even reinforced concrete structures.

People, remarkably, are relatively immune to overpressure itself. But they aren’t immune to collapsing buildings or to pieces of glass hurtling through the air at hundreds of miles per hour or to having themselves hurled into concrete walls — all of which are direct consequences of a blast wave’s overpressure. Blast effects therefore cause a great many fatalities. Blast effects depend in part on where a weapon is detonated. The most widespread damage to buildings occurs in an air burst, a detonation thousands of feet above the target. The blast wave from an air burst reflects off the ground, which enhances its destructive power. A ground burst, in contrast, digs a huge crater and pulverizes everything in the immediate vicinity, but its blast effects don’t extend as far. Nuclear attacks on cities would probably employ air bursts, whereas ground bursts would be used on hardened military targets such as underground missile silos. As you’ll soon see, the two types of blasts have different implications for radioactive fallout...

[TrappedinCalifornia]

Well... It's not all about being in a safe spot in the house...

[zatoh]

If you can't run you might be able to find a place in the city to hide if you planned it all out and you had advanced warning. If you were up to waiting for the radiation to subside you might survive the initial blast. It would really suck though. We used to have bomb shelters all throughout the city. You may occasionally find a sign in an older building or still see air raid sirens in certain parts of the city.

[TrappedinCalifornia]

Originally Posted by zatoh

If you can't run you might be able to find a place in the city to hide if you planned it all out and you had advanced warning. If you were up to waiting for the radiation to subside you might survive the initial blast. It would really suck though. We used to have bomb shelters all throughout the city. You may occasionally find a sign in an older building or still see air raid sirens in certain parts of the city.

Civil Defense, as related to nuclear attack, has been a joke for decades.

From November 2022... Where Are All the Nuclear Bunkers?

...Garrett said it is important to keep in mind the difference between a blast or bomb shelter and a fallout shelter. A bomb shelter is designed to protect people from the explosion of a nuclear or conventional weapon.

"Switzerland, for instance, has space for 100 percent of their population inside blast shelters, which is an amazing feat of engineering," he said.

A fallout shelter, meanwhile, is not designed to shield people from a nuclear blast but is intended to provide protection from the resulting fallout—radioactive debris that is propelled into the atmosphere following a nuclear explosion and eventually falls to Earth.

While the U.S. government did not provide bomb shelters for the public, unlike Switzerland and the Soviet Union, it did implement a fallout shelter program during the Cold War.

This program involved designating thousands of spaces—such as parking garages or the basements of public buildings—across the country as fallout shelters while stocking them with supplies. New York City alone was home to around 18,000 of these...

In other words, other than for high level politicians and 'prepared' individuals, there never really was any infrastructure for surviving a nuclear shockwave. The intended purpose of the public shelters was protection from fallout and even that was never really appreciably maintained. As an example...

I took a look at a town I'm fairly familiar with here in California using the NukeMap link I provided in Post #9. I set off a "Fat Boy" sized, single weapon and they automatically placed the detonation location 2.5 blocks from what used to be the major, public fallout shelter downtown. Let's just say that what used to be the public fallout shelter (it hasn't been considered that for decades and even the warning siren was removed LONG ago) was located just outside the fireball radius and that's a relatively small yield bomb by today's standards.

Another public shelter in that immediate area was a 15 - 20 minute drive from that location; assuming no traffic or congestion. If you could get there and were allowed inside, even back in the 1970's, which was the last time I 'toured' that location, it was a joke. There were absolutely no supplies and no air filtration; let alone 'facilities,' be they medical, sanitary, or other.

The next, closest 'shelter' location was an 'hour' away and it was never, officially, designated as such. It was simply 'studied' for its potential. It was determined that those who sheltered there might survive 'the blast' in that location, but too many resources would have to be dedicated to making it 'safe' from fallout and given the relative location, not to mention being insufficient for a significant portion of the 'local' population, it was abandoned as impractical.

Let's just say that the 'town' is, today, a city and 'more closely' located to other 'towns' which have also become cities. Let's further stipulate that the potential targets have multiplied, making the use of a single vs. multiple warheads... uh... unlikely.

Back in the 1980's, I put together a project 'mapping' nuclear targets in California using publicly available information. (Never mind the 'classified' locations given that I was only aware of some of them and wasn't necessarily at liberty to discuss those.) Let's just say that many who were given access were 'surprised' in that a good part of the State was marked with primary, secondary, and tertiary targets; severely 'disrupting' what had been, to that point, considered 'appropriate' planning.

Thus, your... "If you can't run you might be able to find a place in the city to hide if you planned it all out and you had advanced warning." ... becomes relative to the "might" and you would need to add the word sufficient to "advanced warning."

That's assuming you actually survived the initial blast; something Civil Defense shelters were never intended for.

Therefore, GeeBee49's comment...

Originally Posted by GeeBee49

I know this thread is about surviving the initial blast/shockwave but I think anyone living near one of the target cities needs to consider the aftermath as well. Radiation poisoning from the fallout carries a death sentence of two days or two weeks and is a horrible way to die.
One comment that seems to always follow any discussion on nuclear war is that the living will envy the dead.

...has merit. That's without even considering the largely internal Government 'debates' over whether the public should even be 'warned' that such an attack was in progress and what level of Government would be responsible. You might note what NPR reported in 2018... Who Should Warn The Public Of Nuclear War?

...But Federal officials say it's not their role to warn the public about missiles. "FEMA will tell the states that there's a missile inbound and where it's going to land," says Mark Lucero, chief of engineering for IPAWS. "And then the state will initiate any plans it has in place, one of which being issuing an alert to the public, telling them what to do."

FEMA's national warning system manual echoes that localism: Once federal authorities have used the National Warning System (NAWAS) to alert state and local authorities of the missile threat, "Local authorities sound the Attack Warning signal on public warning devices."

This comes as a surprise to many of those local emergency management officials...

That's assuming a military attack. Today, the Department of Homeland Security seems to be more focused on... NEWS & TERRORISM COMMUNICATING IN A CRISIS: Nuclear Attack. Part of the reason for that focus is the greater potential for a lack of warning. Yet, as Governments do, the underlying premise is: "Listen to Government officials and follow their directions."

Once again... As has often been asked... How many days did it take FEMA to get water to the Superdome?

Such speaks to the very heart of why Americans used to never really rely on Government if they were 'serious' about surviving a nuclear exchange (or just about any other 'disaster' for that matter) and whether 'survivalist/prepper' mentalities were appropriate. It was a discussion which came up in relation to an episode of The Twilight Zone ("The Shelter")...

[sealocan]

I've extensively studied physicist/bioscientist Bruce Banner's work on gramma radiation.

His technical papers were filled with lots of scientific jargon like
"ME-SMMASH" but I think the gist of what he was saying was very counterintuitive...
So I will run towards that "grammar radiation" and try and soak up as much as possible.

Sure you might get a little cranky, rip your clothes, wake up later and not know anything about what you did... but most of us here are doing that stuff anyway.







Wait is it grammar radiation or Grandma radiation? Because I know one is for Big Pimpin, and the other one is still annoying but less harmful.

[TrappedinCalifornia]

This is what they are talking about when they reference a nuclear shockwave...



This was a test of the atomic cannon in 1953.

Detonating at 524' above ground with a 15 kiloton yield, it was shot from 7 miles away.

As a basis of comparison, the Hiroshima bomb had an approximate 16 kiloton yield and the Nagasaki bomb had an approximate 21 kiloton yield.

Put out on 5 October 2022 by The Washington Post... Here are the nuclear weapons Russia has in its arsenal

...Modern strategic nuclear weapons have enormous power. Standard ones can have yields of 500 kilotons, 800 kilotons and even 1 megaton — equivalent to 1 million tons of TNT. Russia holds the record for the most powerful weapon ever exploded: In 1961, it tested a bomb of at least 50 megatons, nicknamed “Tsar Bomba” — or the ruler of all bombs.

Modern tactical weapons usually have a capacity of 10 to 100 kilotons, which still makes the average tactical weapon potentially more destructive than the bombs used on Hiroshima and Nagasaki. Russia and the United States also have “low-yield” nuclear weapons that pack a “light” punch, even dipping below 1 kiloton. But even the least-powerful nuclear bomb — with a yield of about 0.3 kilotons — has about the same explosive power as the 2020 Beirut port explosion...

In other words, by today's standards, the 1953 explosion in the video was equivalent to a small, tactical weapon.

Remember, the study done in the OP assumed a 750 kiloton weapon.

In February of 2015... What would happen if an 800-kiloton nuclear warhead detonated above midtown Manhattan?...

Russian intercontinental ballistic missiles are believed to carry a total of approximately 1,000 strategic nuclear warheads that can hit the US less than 30 minutes after being launched. Of this total, about 700 warheads are rated at 800 kilotons; that is, each has the explosive power of 800,000 tons of TNT. What follows is a description of the consequences of the detonation of a single such warhead over midtown Manhattan, in the heart of New York City...

[TrappedinCalifornia]

So... Who do we believe? From the OP (bold emphasis mine)...

...The worst places to hide seem to be in the direct vicinity of the windows, door openings, and hallways, since this is where the air will be most funneled through in the shockwave. But airspeeds are likely to be lowest in the room corners away from these openings along the walls facing the blast, so these areas should be the best to take immediate shelter. The researchers created a model showing where air velocity is likely to be highest inside a building...

Or, do we go with last year's piece... How to survive a tactical nuclear bomb? Defence experts explain...

...Next will come the blast wave. This consists of an overpressure shock wave followed by an outward blast wind, often with reverse winds returning to ground zero...

The shock wave travels faster than the speed of sound (about 343 metres per second). So if you’re one kilometre away from the epicentre, you have less than three seconds to find cover. If you’re five kilometres away, you have less than 15 seconds...

The incoming shock wave will reflect off the internal walls, superimposing with the original to double the pressure. Avoid the explosion side of the building and make sure to lie down rather than stand...

Well... At least they agree on avoiding doors, windows, and things that can fall on you.

Could it be that we're simply back to Bert the Turtle (see the OP) and the fact that we're, in essence, dealing with theoretical abstraction?

Or... Is it really not so much theoretical abstraction...



... but more a function of sufficient warning, distance, size of explosion, and the fact that it's more about the blast wave than the shock wave?

Or... Is that splitting things a little too fine in that the blast wave is, in essence, the same thing as the shock wave?

High-speed Imaging of Shock Waves, Explosions and Gunshots (bold emphasis mine)...

...A shock wave has no substance itself; rather it is an extremely thin wavefront that passes tsunami-like through solids, liquids and gases at high speeds, driven by molecular collisions at the nanoscale. It is defined as a compression wave—a sudden spike in pressure followed by a sudden drop in pressure—formed, for example, when the speed of an object (such as a bullet) is faster than the speed at which the surrounding medium (such as air) transmits sound.

Sound waves in the air, whether from a whisper or a yell, travel at the speed of sound, called a, for "acoustic" speed. This speed depends on air temperature, but a is typically about 340 meters per second in "standard" air. Shock waves, on the other hand, travel faster than a, being supersonic wave phenomena. They're also stronger and more energetic than sound waves, are highly nonlinear and cause significant jumps in temperature, pressure and density of the air over their wave thickness of only nanometers. The passage of a strong shock wave through the human body, for example, causes severe damage owing to the large instantaneous pressure change...

Close to an explosion, a shock wave can travel at several times the speed of sound and reach pressures of ten or more atmospheres, producing devastating effects. Also, the "wind" that immediately follows a strong shock wave is brief but very intense. In an explosion, the fireball expands very quickly and pushes air ahead of it. As the shock wave ripples out from the explosion center, the speed of its following wind is the same as the speed of expansion of the initial fireball. A shock wave at a mere Mach 1.3 already has a stronger following wind than the fastest natural tornado-generated wind speed ever recorded. Footage of pre-1963 aboveground nuclear tests shows the shock wave smashing whole buildings, whose debris is then swept downrange by the following wind...

But strong shock waves are also devastating to structures. In the 1995 terrorist bombing of the Murrah Federal Building in Oklahoma City, a huge truck bomb was detonated only a few meters from the building. The resulting strong shock wave and its many concomitant effects destroyed the columns supporting the north face of the building, whence it collapsed. As a result, 168 lives were lost and there were many more injuries. Both experiments and computational blast simulations now help inform building designers on how to mitigate such lethal effects and how to prevent building collapse and improve survivability...

The evolving flowfield of a gunshot is rather complicated over a period of several milliseconds. The interior ballistics of firearms cannot be observed by the methods described here, so the first visible phenomenon at the muzzle is the emergence of the bullet-driven shock wave, followed immediately by the bullet itself. Then the propellant gases, the products of gunpowder combustion, exit and expand tremendously as they transfer from high pressure inside the barrel to one atmosphere outside. This rapid expansion behaves like an explosion in pushing the air out of the way and thus generating a strong spherical shock wave, or muzzle blast. The "bang" of a gunshot is almost always caused by this muzzle blast...

Blast Wave

...The front of a blast wave and the front of a shock wave are physically the same. Blast waves are primarily differentiated from generic shock waves by the negative-pressure blast wind that trails them. Furthermore, a shock wave may be created by a number of different sources (such as any object reaching supersonic speeds), whereas blast waves are created exclusively by the detonation of explosive material...

In other words, for those who were having a little trouble, while the terms blast wave and shock wave are, kind of, synonymous, technically, there is a difference in that a blast wave is a form of shock wave. Put another way, who you believe is likely going to depend on whether you feel it is more important to have sufficient warning/distance and the size of explosion or an intimate understanding of the technical difference between a blast wave and a generic shock wave.

All of which was more pithily stated in the first reply to this thread...

Originally Posted by Citizen_B

While interesting, I'm not sure how much practical/actionable value this info may have. The first assumption is you're in the goldilocks region of close enough to get the damaging wind effects of a shockwave, but far enough away where the heat/shockwave doesn't obliterate your entire house. Then you have to be aware that the shockwave is coming before it arrives, which would be noticing the intense bright light and recognizing it as a nuclear explosion. And being able to notice that without going blind, which if one was blind and in pain, good luck rapidly finding a safe place to hunker down for the imminent shockwave. I suppose this info might be useful if a nuclear attack is expected/possible so one could consider it for a sleeping location.

[user120312]

Remember this?
https://www.youtube.com/watch?v=VBV8nnp98vc

That was about 2.75 kilotons of ammonium nitrate at ground level.

[TrappedinCalifornia]

Originally Posted by user120312

Remember this?
https://www.youtube.com/watch?v=VBV8nnp98vc

That was about 2.75 kilotons of ammonium nitrate at ground level.

Beirut explosion was one of the largest non-nuclear blasts in history, new analysis shows

...The new assessment by the Sheffield engineers, which is published in the journal Shock Waves, found that the size of the explosion was the equivalent of between 500-1100 tonnes of TNT - around 1/20th of the size of the atomic bomb that was used on Hiroshima on 6 August 1945 and is one of the largest non-nuclear explosions ever recorded...

You might also note Post #21.

In other words, the Beirut explosion was, in the grand scheme of things, inconsequential when compared to a nuclear weapon.

As a basis of comparison, you might try... How powerful was the Beirut blast?

A more scientific discussion of that blast can be found... Yield estimation of the 2020 Beirut explosion using open access waveform and remote sensing data... to arrive at approximately the same conclusion...

...All three independent methods that we applied (seismological analysis, acoustic yield relations, satellite radar image analysis) consistently estimate the range of the yield within one order of magnitude. The lowest yield estimate of 0.13 kt TNT is given by the seismic body wave analysis and the largest yield estimate of up to 2 kt TNT stems from relating reported damage and an InSAR damage proxy to peak overpressure. It has been shown that such yield estimates, even under ideal conditions and especially for chemical explosions, can vary strongly. For this study we believe that methodological uncertainties such as energy coupling from the surface into the ground or atmospheric propagation modelling are the most significant contributors to uncertainties in our yield estimations...

[user120312]

I was building explosives back in the sixties and thank you for making my point.


That's what even a comparatively tiny explosion can do.

[DaveInOroValley]

This is obviously the best place:

[TrailerparkTrash]

Good to know useful information.

So if you survive the initial blast by hiding in the corner, you’ll only have to deal with the severe, painful and slow death from radiation poisoning all over your body and inside the lungs, mouth and sinus cavity.

I’d rather die immediately in the blast if I’m that close to ground zero.

[user120312]

Besides the remarkable, if believable, tales of the Jesuit eight, there were also first hand accounts of how location and position enabled survival of both the blast and subsequent radiation. One sample from a Jesuit priest who was there when Japan was bombed....
https://youtu.be/7OSigsRhSRA?t=355
I located to high ground mainly to avoid tsunamis at anything but a cataclysmic level but forested canyon living also could provide some protection from atomic events as the story from the Jesuit underscores, in his case with their mission, being four miles from epicenter, having a hill between them and the city area where the blast took place.

[TrappedinCalifornia]

Originally Posted by TrailerparkTrash

Good to know useful information.

So if you survive the initial blast by hiding in the corner, you’ll only have to deal with the severe, painful and slow death from radiation poisoning all over your body and inside the lungs, mouth and sinus cavity.

I’d rather die immediately in the blast if I’m that close to ground zero.

The shock or blast wave travels significantly farther and faster than the initial radiation exposure.

...After 10 seconds, when the fireball of a 1-megaton nuclear weapon has attained its maximum size (5,700 feet across), the shock front is some 3 miles farther ahead. At 50 seconds after the explosion, when the fireball is no longer visible, the blast wave has traveled about 12 miles. It is then traveling at about 784 miles per hour, which is slightly faster than the speed of sound at sea level....

When it comes to radiation, as you suggest, if you are close enough to ground zero, you won't have long to worry about exposure. If you survive the blast, then there are different types/exposures you then need be concerned with...

...Initial nuclear radiation is defined as the radiation that arrives during the first minute after an explosion, and is mostly gamma radiation and neutron radiation.

The level of initial nuclear radiation decreases rapidly with distance from the fireball to where less than one roentgen may be received five miles from ground zero. In addition, initial radiation lasts only as long as nuclear fission occurs in the fireball. Initial nuclear radiation represents about 3 percent of the total energy in a nuclear explosion.

Though people close to ground zero may receive lethal doses of radiation, they are concurrently being killed by the blast wave and thermal pulse. In typical nuclear weapons, only a relatively small proportion of deaths and injuries result from initial radiation...

The residual radiation from a nuclear explosion is mostly from the radioactive fallout. This radiation comes from the weapon debris, fission products, and, in the case of a ground burst, radiated soil.

There are over 300 different fission products that may result from a fission reaction. Many of these are radioactive with widely differing half-lives. Some are very short, i.e., fractions of a second, while a few are long enough that the materials can be a hazard for months or years. Their principal mode of decay is by the emission of beta particles and gamma radiation...

This is why the Government says to get inside and stay inside...

...GET INSIDE: After a detonation, you will have 10 minutes or more to find an adequate shelter before fallout arrives. If a multi-story building or a basement can be safely reached within a few minutes of the explosion, go there immediately. The safest buildings have brick or concrete walls...

FEMA has a pamphlet...

...Fallout is most dangerous in the first few hours after the detonation when it is giving off the highest levels of radiation. It takes time for fallout to arrive back to ground level, often more than 15 minutes for areas outside of the immediate blast damage zones. This is enough time for you to be able to prevent significant radiation exposure by following these simple steps...

It's the same, basic advice we've heard for almost 80 years. But, this piece, from 2014, might be of interest... How to Survive a Nuclear Explosion...

...During the Cold War, scientists modeled almost every imaginable consequence of a nuclear explosion. But Dillon found a gap in the sheltering strategies for people far enough from ground zero to survive the initial blast but close enough to face deadly fallout. He focused on a single low-yield nuclear detonation like those that destroyed Hiroshima and Nagasaki. The world's nuclear arsenal has grown far more powerful—today's warheads can inflict thousands of times more damage—but security experts believe that low-yield bombs are the kind most likely to be used by terrorists.

The hard part was figuring out what variables matter for fallout survival. The rest was calculus. The longer you stay outside, the higher your radiation dose, but the environmental radiation intensity also decreases over time. So your total dose is a function of when you step outside, your distance from the detonation, how long you run before you reach better shelter, and how much shielding you get from the local environment while you're out there. Dillon simplified the calculation by assuming that you are totally exposed while running to safer shelter; he also ignored complexities such as limited shelter capacities. In the end, the math boiled down to a single critical number: the ratio of the time you spend hunkering down in your first shelter to the time you spend moving to the high-quality shelter. Then Dillon worked out what would happen with a variety of shelter options and transit times.

The results surprised him. For low-yield nuclear detonations, you can do far better than just sheltering in place, but you'll need a watch and good knowledge of your surroundings. If your current shelter is poor and higher quality shelter is less than 5 minutes away, the model suggests that you should run there as soon as you can. If you have poor shelter but higher quality shelter is available farther away, you should get to that high-quality shelter no later than 30 minutes after detonation. Depending on the size of the city, if everyone follows this advice, it could save between 10,000 and 100,000 lives, Dillon reports online today in the Proceedings of the Royal Society A...

Illustration from the link in the above quote...



From the same link...

...There are several important practical considerations in the use of these methods. First, caution should be used in determining the appropriate evacuation dose since route congestion, e.g. traffic jams, can increase the evacuation time (and dose) above that originally assessed (see [3] for more details). Second, as noted in table 1, other factors, such as food, water, medical needs and impending hazards (e.g. fire), may also need to be considered. Inclusion of these factors is beyond the scope of this study. Third, knowledge of the fallout arrival time allows for improved decision-making. However, use of this information increases the decision-making complexity. Fourth, while many of these methods do not require knowledge of the absolute dose rate in determining the optimal shelter time, particular attention should be paid to ensuring that individuals most at risk, e.g. those located in high dose rate regions, act optimally. Finally, the implementation of these methods will require effective emergency communications and instructions which should be carefully scripted and tested. The interested reader is referred to [13] for examples of current US nuclear detonation response messages...

The bottom line is that nobody has said or is seriously suggesting that if you are standing at Ground Zero that you've got a 'realistic' chance. At Ground Zero, the toughest, luckiest, etc. individual is, in all probability, gonna die; usually from the blast or initial radiation. The bottom line is that there are limits as to what can be 'prepped' for and long have been the debates and research over what it would take in terms of an adequate shelter/bunker within Ground Zero.

But, what 'prepping' does is 1.) provide a sense (realistic or not) that you have some 'control' over your destiny and (2.) create a potentially increased set of odds that you will survive. While one cannot count on or even exercise much, if any, actual control, just the 'sense of control' helps many psychologically. Put another way, if you don't see a point, then Life itself is pointless in that we are all survivors/survivalists from the moment of conception. While there are limits to our ability to 'control' things and what or how much we can prepare for, as most survival instructors point out, actual survival is roughly 90% psychological and 10% physical.

That's the point of 'prepping.' While there are limits to what you can do in regard to the 10%, there's virtually no limit as to how you deal with the 90% beyond the amount of time/effort you put into it. The more you know or the better 'prepared' you are, the more you can 'control' or the better your odds of 'controlling' the physical circumstances.