EMP, Why bother?

[Squidi]

SO, if most cars directly struck by lightning are driveable aftewards, why would an EMP fry all cars so they won't be driveable? Are EMPs going to be much more powerful than direct lighting strikes?

I'll try. An EMP is electromagnetic radiation inducing a current in wires that are acting as antennas. Lightening is the earth and sky balancing a charge with your car in the way. My understanding is that the lightning goes around the car, conducted by the water to the ground.

I bet it blows the radio up either way.

Back when I had 300 feet of unshielded ethernet cable running out of my house and up a 60 ft tower, I would get induced charge from lightening blowing up switches and ethernet ports on equipment.

[Bunsen]

I'm not an electrician, maybe some of you folks can explain this for me.

The vast majority of cars DIRECTLY hit by lightning have little to no damage done to them, and the occupants inside are most often safe, and the cars are driveable afterwards, and most often start. (this is from auto insurance claims data). Yes, some cars are fubar, but many are very driveable afterwards, so much so that insurance claims adjusters have trouble finding evidence of lighting strike to backup claims for paint or tire damage.

How come? --- little google tells me that high voltage electricity likes to travel around the outside of the conductor. OK whatever.

SO, if most cars directly struck by lightning are driveable aftewards, why would an EMP fry all cars so they won't be driveable? Are EMPs going to be much more powerful than direct lighting strikes?

Thanks!

There are significant differences (most importantly, timescale), but a nuclear EMP won't cause permanent damage to most cars. It tends to cause sensor hiccups that can upset the operation of the engine and maybe cause a stall, but the last time a batch of cars were tested in a NEMP simulator, not one suffered damage if it was off during the pulse. (They didn't test the radios; those were certainly toasted.) As I quoted in one of the previous threads on this,

The testing was conducted by exposing running and nonrunning automobiles to sequentially increasing EMP field intensities. If anomalous response (either temporary or permanent) was observed, the testing of that particular automobile was stopped. If no anomalous response was observed, the testing was continued up to the field intensity limits of the simulation capability (approximately 50 kV/m).
Automobiles were subjected to EMP environments under both engine turned off and engine turned on conditions. No effects were subsequently observed in those automobiles that were not turned on during EMP exposure.
...
Eight of the 37 cars tested did not exhibit any anomalous response.
...
Of the trucks that were not running during EMP exposure, none were subsequently affected during our test.
...
The other 10 trucks that responded exhibited relatively minor temporary responses that did not require driver intervention to correct. Five of the 18 trucks tested did not exhibit any anomalous response up to field strengths of approximately 50 kV/m.

That episode of Future Weapons everybody refers to? They cherry-picked one of the few vehicles that the simulator was capable of damaging. Showing a car blinking some dashboard lights but continuing to run like nothing was wrong wouldn't make for good TV, after all.

The reason that an EMP can mess with the car's electronics and the lightning can't comes down to timing and wavelengths. A lightning strike takes a good portion of a millisecond to ramp up to its full current, and longer to ramp down -- that means the highest frequencies involved are in the range of a few kilohertz. Electromagnetic waves at those frequencies have wavelengths in the hundreds of kilometers.

Holes in a Faraday cage can allow radiation in if the holes are comparable to or larger than the wavelength of the radiation. The gaps in a car's body are on the order of a meter, so hundred-kilometer long waves from a lightning strike are effectively shielded. A nuclear EMP produces much higher frequencies, with much of the energy coming in the tens to hundreds of megahertz, i.e. wavelengths down to and below a meter. That gets through a car's frame and body much more easily, but it still tends not to cause permanent damage to things that don't have antennas.

[calearner]

It's not the EMP itself that worries me, but the second order effects.

Let's ignore the ways humans can trigger it, and just worry about the Sun. This event has happened before, and will happen again. When ? I don't think anyone can know that.

If the EMP comes from a large source like a large solar Coronal Mass Ejection, then I think many experts believe that an awful lot of high voltage transformers will explode and become useless. Because every one of them looks like a huge antenna (i.e. the power grid wires connected to them) to an EMP.

I believe the lead time on replacing a lot of these transformers is long - 18 months or so. And that there are not a lot of spares available in the world.

If there are no step-down transformers, then it doesn't really matter to me if my toaster is working or not - I'm pretty sure my toaster can't run on the 300,000 volts that power generation stations put out.

My toaster not working isn't the end of the world. But if the water pumps that bring water to my community stop working because there's no power for them, that becomes serious. If the fuel pumps that bring gasoline up from underground fuel tanks to the gas station's nozzle can't get power and stop working, that becomes serious. If food processing factories can't operate and can't deliver food to supermarkets, that becomes serious.

It seems to me that the result of EMP means a 1-6 month breakdown in water, fuel, and food for any area (like the heavily populated coasts) that imports more of this stuff than produces it. And if that isn't something to worry about, I'm not entirely sure what I should be worrying about. Besides Zombies, of course.

[DarkAxel]

Here's a list of MY EMP preps.

A shitload of candles, oil lamps, and gas lanterns.
The ability to grow and raise my own food.
The ability to preserve my own food.
The food I have stockpiled in the cupboard.
A well that I can use without electricity.
For the crowds of panicked strangers, looters and the like, personal and family protection in the form of firearms, with plenty of ammo to feed them.
A heating stove, with a ton of coal and a hillside full of timber behind the house.
A disaster plan.
Involving my neighbors and friends.

In essence, the same preps I have for everything else.

[Silent Kube]

Here's a list of MY EMP preps.

A shitload of candles, oil lamps, and gas lanterns.
The ability to grow and raise my own food.
The ability to preserve my own food.
The food I have stockpiled in the cupboard.
A well that I can use without electricity.
For the crowds of panicked strangers, looters and the like, personal and family protection in the form of firearms, with plenty of ammo to feed them.
A heating stove, with a ton of coal and a hillside full of timber behind the house.
A disaster plan.
Involving my neighbors and friends.

In essence, the same preps I have for everything else.

Exactly. I'm prepped to be without power regardless. EMP or not, when SHTF I don't expect for there to be power so I plan accordingly.

[kiwilrdg]

Kube,
Your signature has the key to additional preps for EMP

I think we're all pretty much just bullshitting here, which is what the Internet is for. Besides porn.

Keep extra porn and ensure you have a neighbor to bullshit with when the internet is down.

[Silent Kube]

Removed due to questionable taste.

[raptor]

Kube and kiwilrdg we need to stick to the subject of EMP.

Thanks.

[kiwilrdg]

Kube and kiwilrdg we need to stick to the subject of EMP.

But that is the only way EMP would affect us.

[mantis]

SO, if most cars directly struck by lightning are driveable aftewards, why would an EMP fry all cars so they won't be driveable?

I'll have to dig out the link but according to fairly recent US government testing most WILL be perfectly driveable after being exposed to an EMP. In virtually all cases where the car was turned off, there was absolutely no impact and in something like 75% of the cases where the car was running, it simply stalled and could be immediately restarted with anywhere from no damage to systems to minor systems damage.

Edit: Oops...I didn't notice that Bunsen had already posted pretty much what I just said.

[RoneKiln]

Nearly ten years ago some technicians made a mistake while monitoring the electrical grid in Seattle. I no longer remember what it was, but it ended up sending a power surge through the grid that blew out everything in my neighborhood 80 miles away. The local substation was down for two days, a power line down the street exploded (I thought it was a gunshot when it blew), half the breakers in my home had to be replaced (they did not just trip, but were fully fried), and anything not in a surge protector was fried. Even many of the light fixtures needed replacing. This damage was through the entire neighborhood. Some of the surrounding substations took longer to repair than ours.

I doubt any of this means anything in event of an EMP attack. It does leave me suspicious of the electrical grids ability to protect itself from larger solar events. Perhaps newer grids have massive surge protectors that need only be flipped to bring them back online, but I bet we have a lot of aging systems that don't. If 80 miles isn't a long enough distance to have these big surge protectors in place, I can see a lot of damage being done from a major solar event unless there's been a lot of upgrading to my local system in the last ten years.

[DrunkWookiee]

This has already happened in recent history. The 1989 Quebec Blackout.

http://en.wikipedia.org/wiki/March_1989 ... etic_storm

http://www.youtube.com/watch?v=KqXtwAZFfUQ

[TDW586]

This has already happened in recent history. The 1989 Quebec Blackout.

http://en.wikipedia.org/wiki/March_1989 ... etic_storm

http://www.youtube.com/watch?v=KqXtwAZFfUQ

So...power was out for nine entire hours? Scary stuff.

[DrunkWookiee]

This has already happened in recent history. The 1989 Quebec Blackout.

http://en.wikipedia.org/wiki/March_1989 ... etic_storm

http://www.youtube.com/watch?v=KqXtwAZFfUQ

So...power was out for nine entire hours? Scary stuff.

What I find scary about the incident is that some thought a nuclear first-strike was underway

[raptor]

Our civilization is so dependent upon power when it goes out it can lead to civil disorder, looting and other problems. Most ZS'ers view a power outage as good practice, others view it as an opportunity to go shopping with a sledge hammer.

So yes a 9 hour unexpected power outage is a problem. My neighborhood (not me though ) was without power for week after Hurricane Gustave in 2008. A prolonged power outage causes a wide variety of problems for many people.

[TDW586]

Our civilization is so dependent upon power when it goes out it can lead to civil disorder, looting and other problems. Most ZS'ers view a power outage as good practice, others view it as an opportunity to go shopping with a sledge hammer.

So yes a 9 hour unexpected power outage is a problem. My neighborhood (not me though ) was without power for week after Hurricane Gustave in 2008. A prolonged power outage causes a wide variety of problems for many people.

True, I suppose I don't take power outages as seriously as some do. I grew up in rural North Carolina, and power outages for anything from a day to a week was just par for the course when the ice storms started up in the winter.

We'd make sure we had candles, drag out the chainsaws and axes in case trees went down across the driveway, then play some board games and wait for the power to kick back in. I actually kind of enjoyed it as a kid.

[Rev]

The real threat from EMP is not in the rural areas, since by and largely they're much better set to withstand a multiple week power outage. The cities on the other hand are not. I can think of a couple cities that riot when the lights flicker, let alone a week long power outage. If it's more than a couple weeks or a month and a large area is affected, you'll start to get people dying because you can't get water to them. No power, and shortly thereafter you'll have no water. I'd also think that this type of attack would tank our economy right now. If everyone even followed the base guidelines of FEMA our nation could probably get by even one of the moderate to worst case scenarios on EMP. Sadly we seem to be based totally around waiting for the Federal government to come fix everything, and that doesn’t work on large localized disasters let alone a nationwide one. So, what should we do to prepare about EMP? Almost nothing different than normal preps, and maybe trying to bring it to the attention of local leaders so they can at least get a plan on the books. No biggy, no reason to fight about it, just another contingency to plan for. You don’t even have to go super crazy on shielding your hardware, since most of it isn’t that vital you’d die without it. The big thing is community awareness and cooperation and I believe that is already encouraged by ZS anyway. Don’t knock the folks who plan for EMP as being crazy tin foil hate wearers either. EMP in it’s extreme theorized form is probably more terrifying and destructive than a zombie apocalypse so I do not judge someone who plans accordingly since they are probably quite prepared for every other contingency because of it. Isn’t that the point of our “zombies” in the first place?

[johnwiseman]

Power outages are a thing to prep for, no doubt. Look at the North east blackouts and and imaging that in your home town. But to prep your car for EMP? To worry about your motorcycle choice because of EMP? To try and build some cage thingy around your home because an EMP might brake your TV? Seriously, even if you did have the cage, wouldn't the EMP surge from outside your house blow up all your shnit anyways? I understand the idea of prepping for outages in general and I do myself. But worrying about an EMP specifically is BS.

[Rev]

Power outages are a thing to prep for, no doubt. Look at the North east blackouts and and imaging that in your home town. But to prep your car for EMP? To worry about your motorcycle choice because of EMP? To try and build some cage thingy around your home because an EMP might brake your TV? Seriously, even if you did have the cage, wouldn't the EMP surge from outside your house blow up all your shnit anyways? I understand the idea of prepping for outages in general and I do myself. But worrying about an EMP specifically is BS.

Most people who prep for it just have a small faraday cage where they put backup equipment and parts. Stuff your storing anyway so it makes sense to harden it. I also know a few people who have older style communication devices that are still quite serviceable and durable while also being fairly immune to EMP. They have them as a backup for their modern systems incase of EMP or even just something breaking. A lot of people also get the older "EMP proof" vehicles because most of them can be repaired manually while if something goes wrong with certain systems in a modern car you're screwed. Besides, this isn't a simple power outage. It's almost impossible to imagine a nationwide power outage and the hell that would cause. How do you get your water? What pumps that water to your house and puts pressure on the lines? Sure we've all gone without power, and people like me have lived through multiple week power outages in the middle of an ice storm. Turn off the power and water for a city, and it's a humanitarian disaster within days. Should this go on for multiple weeks/months you'll get people dying. If it's multiple cities there is no way for our government to get aid to everyone who needs it. I know a lot of people put great faith in our government and our electric grid, but even they say it’s for all intents and purposes a third world system. Just a really big one.

[Browning 35]

SO, if most cars directly struck by lightning are driveable aftewards, why would an EMP fry all cars so they won't be driveable?

I'll have to dig out the link but according to fairly recent US government testing most WILL be perfectly driveable after being exposed to an EMP. In virtually all cases where the car was turned off, there was absolutely no impact and in something like 75% of the cases where the car was running, it simply stalled and could be immediately restarted with anywhere from no damage to systems to minor systems damage.

Edit: Oops...I didn't notice that Bunsen had already posted pretty much what I just said.

You're talking about this aren't you???

From what this article says ...Nuclear Electromagnetic Pulse by Jerry Emanuelson Futurescience, LLC (*Click*)....many motor vehicles would still run after an EMP test. The vehicle would just go dead initially from the EMP pulse and you'd have to work on it and have the necessary car/truck parts and knowledge to get it running again.

Many of the effects of nuclear EMP are very difficult to predict on the 21st century United States. Many vehicles that one would expect to be disabled by an EMP due to their dependence on sensitive electronics might be shielded well enough to continue to operate. Automotive electronic ignition systems in general are much better shielded and protected against EMP than other electronics. (After all, the purpose of an electronic ignition is to make high-voltage sparks.) Circuits in the automobile outside of the electronic ignition are actually the most vulnerable. Actual tests on vehicles in simulators have been very inconsistent. Even if only ten percent of the automobiles on the highways during the day were abruptly disabled, the resultant traffic jams would be nearly incomprehensible. (Having ten percent of the cars suddenly disabled might actually be more chaotic than having nearly all of them suddenly disabled.) Of course, there is no practical way to do a real nuclear EMP test. Even a nuclear test in space over the Pacific would likely do billions of dollars in damage to today's electrical and electronic infrastructure in the Pacific region.

Tests done on 37 vehicles (that used electronic ignition systems) by the United States EMP Commission showed that all of the tested cars would still run after a simulated EMP, although most sustained some (mostly nuisance) electronic damage. Only about one in every ten million civilian automobiles and light trucks in use today have been tested in an EMP simulator. That is a very tiny sample size. Many cars that would run after an actual EMP would probably have to be started in an unconventional manner (such as temporarily jumpering wires under the hood) due to damage of control circuits.

Reports about the effects of the 1962 Starfish Prime test that have been declassified in recent years state that some of the automobiles in Hawaii had their old non-electronic ignition systems damaged by the EMP, so automobile damage may be much higher that we previously thought. Most of the people whose cars were damaged by the Starfish Prime test probably never related their car ignition problems to the nuclear test. The damage to diesel generators in the 1962 Soviet nuclear EMP tests indicates that some of the electrical damage doesn't show up right away. Although many people would like to know exactly which vehicles would continue to function after an EMP, the number of variables are enormous, and include the orientation of the vehicle with respect to the detonation point at the particular time that the device is detonated.

Power outages are a thing to prep for, no doubt. Look at the North east blackouts and and imaging that in your home town. But to prep your car for EMP? To worry about your motorcycle choice because of EMP? To try and build some cage thingy around your home because an EMP might brake your TV? Seriously, even if you did have the cage, wouldn't the EMP surge from outside your house blow up all your shnit anyways? I understand the idea of prepping for outages in general and I do myself. But worrying about an EMP specifically is BS.

No, not unless the EMP was from a nuclear weapon being detonated by hitting the ground. EMP can be a weapon all on it's own and it doesn't neccessarily have to come from an ICBM actually striking US soil. Such a weapon could be detonated far above the US in the atmosphere and still cause major havoc and chaos.

EMP Effects (*Click*)

Understanding asymmetric threats to the US (*Click-PDF*)



As far as the actual power grid and almost all electronic devices goes they would definately be fried and it would take quite a bit of work to get things back to normal. From everything I've read it doesn't matter if the electrical device is plugged in or not, the Gamma Rays will still effect and damage it if it's within the weapons line of sight. The blast has to be within the weapons line of sight though, the Gamma Rays won't continue past the curvature of the earth. So if the EMP blast were detonated fairly low in altitude then the damage would be limited to a specific area.

The higher up it is then there's more damage.

Such an attack could be carried out by a number of nations like China, North Korea, Iran or technically 'friendly' nations like Pakistan or India (just because we have decent diplomatic relations with them today doesn't mean that this will always be the case).

At any rate it's a threat....I don't know how big of one it is or how likely it is to happen (I personally worry more about regular crime, flooding or tornados), but it's still a threat and it could happen.

[raptor]

the number of variables are enormous, and include the orientation of the vehicle with respect to the detonation point at the particular time that the device is detonated.

A good post on the subject. I quoted the above because I do not think this aspect can be stated enough. Random chance (orientation, shielding by buildings/structure/mass, distance from the source, angle of the source, etc.) will no doubt play a significant part in any EMP event.

A vehicle parked 200 miles away from an EMP source in an underground parking lot shielded from the EMP event because it is up against the wall and has 100 feet of earth between it will likely fair better than the same vehicle exposed on a surface parking lot. Both of the vehicles will likely fair better than a vehicle say 5 miles away from such an EMP source.

[Browning 35]

the number of variables are enormous, and include the orientation of the vehicle with respect to the detonation point at the particular time that the device is detonated.

A good post on the subject. I quoted the above because I do not think this aspect can be stated enough. Random chance (orientation, shielding by buildings/structure/mass, distance from the source, angle of the source, etc.) will no doubt play a significant part in any EMP event.

A vehicle parked 200 miles away from an EMP source in an underground parking lot shielded from the EMP event because it is up against the wall and has 100 feet of earth between it will likely fair better than the same vehicle exposed on a surface parking lot. Both of the vehicles will likely fair better than a vehicle say 5 miles away from such an EMP source.

Yeah, it seems like it's one of those 'location, Location, LOCATION' variables that you can't completely control. Common sense would lead you towards the belief that a nation or terrorist group using such a weapon on the US would target major cities (such as New York), but it could really happen anywhere.

There's also the possibility of a Super Solar Storm (*Click*) which could act almost exactly like an EMP detonation. Solar Storms have hit the Earth in the past, but at the time (Thursday, September 1st 1859) mankind wasn't exactly all that dependant upon electricity. It still did some damage though.

At 11:18 AM on the cloudless morning of Thursday, September 1, 1859, 33-year-old Richard Carrington—widely acknowledged to be one of England's foremost solar astronomers—was in his well-appointed private observatory. Just as usual on every sunny day, his telescope was projecting an 11-inch-wide image of the sun on a screen, and Carrington skillfully drew the sunspots he saw.

On that morning, he was capturing the likeness of an enormous group of sunspots. Suddenly, before his eyes, two brilliant beads of blinding white light appeared over the sunspots, intensified rapidly, and became kidney-shaped. Realizing that he was witnessing something unprecedented and "being somewhat flurried by the surprise," Carrington later wrote, "I hastily ran to call someone to witness the exhibition with me. On returning within 60 seconds, I was mortified to find that it was already much changed and enfeebled." He and his witness watched the white spots contract to mere pinpoints and disappear.

It was 11:23 AM. Only five minutes had passed.

Just before dawn the next day, skies all over planet Earth erupted in red, green, and purple auroras so brilliant that newspapers could be read as easily as in daylight. Indeed, stunning auroras pulsated even at near tropical latitudes over Cuba, the Bahamas, Jamaica, El Salvador, and Hawaii.

Even more disconcerting, telegraph systems worldwide went haywire. Spark discharges shocked telegraph operators and set the telegraph paper on fire. Even when telegraphers disconnected the batteries powering the lines, aurora-induced electric currents in the wires still allowed messages to be transmitted.

"What Carrington saw was a white-light solar flare—a magnetic explosion on the sun," explains David Hathaway, solar physics team lead at NASA's Marshall Space Flight Center in Huntsville, Alabama.

Now we know that solar flares happen frequently, especially during solar sunspot maximum. Most betray their existence by releasing X-rays (recorded by X-ray telescopes in space) and radio noise (recorded by radio telescopes in space and on Earth). In Carrington's day, however, there were no X-ray satellites or radio telescopes. No one knew flares existed until that September morning when one super-flare produced enough light to rival the brightness of the sun itself.

Other than buying or building a Faraday cage for a generator and some batteries and perhaps stocking some spare car/truck parts for your vehicles I don't really know what to do about it besides prepping in a normal way.

[Bunsen]

From everything I've read it doesn't matter if the electrical device is plugged in or not, the Gamma Rays will still effect and damage it if it's within the weapons line of sight.

This is wrong. Gamma radiation is rapidly absorbed by the atmosphere -- at sea level, it only takes a few hundred meters of air to reduce the intensity of gamma radiation by a factor of 10. For a weapon intended to produce an EMP, i.e. one detonated in the upper atmosphere, you wouldn't be able to detect its gamma radiation at the surface if you tried. This image you included shows the situation pretty well:

That "Source Region" is where the atmosphere becomes thick enough to absorb the gamma rays, and the process of absorption creates the EMP. The only effect that matters at the surface is the pulse of radio waves, and as has been said more times than I care to count in this thread alone, electronics will only be damaged by that if they have something that acts like an antenna.

[Browning 35]

From everything I've read it doesn't matter if the electrical device is plugged in or not, the Gamma Rays will still effect and damage it if it's within the weapons line of sight.

This is wrong. Gamma radiation is rapidly absorbed by the atmosphere -- at sea level, it only takes a few hundred meters of air to reduce the intensity of gamma radiation by a factor of 10. For a weapon intended to produce an EMP, i.e. one detonated in the upper atmosphere, you wouldn't be able to detect its gamma radiation at the surface if you tried. This image you included shows the situation pretty well.

I honestly don't know if it matters if the electrical device is plugged in or not. I'm not a NASA scientist, never been around a nuclear detonation and I'm going on the basis of 5-6 articles like the ones above, one in Popular Mechanics and a single book ('One Second After' by William R. Forstchen'). :shrug

(Just for clarification purposes I was talking about a nuclear weapon being detonated in the atmosphere, so wouldn't the Gamma Rays hit the electrical device in question just like how I was saying since you said that the illustration was correct???)