Tuesday, July 2, 2013

Looking at the Phenomenon of the Electro-Magnetic Pulse


  When I first heard about electro-magnetic pulses it was within the context of discussing nuclear bombs.  My father explained that electronics would fail following exposure to an electro-magmetic burst in the region of the bomb itself.  I can remember thinking that with skin melting off people and hair dropping out within days, that my transistor radio failing was at the bottom of my list of things to be concerned about if that ever did happen.
              I remember hearing about it again in the nineteen-eighties when I was gathering materials for my own young family's disaster planning, and EMP was not quite so clear, and not quite so easily dismissed.  I fashioned an American-made metal trash can with a well fitting lid. I lined the bottom and sides with styrofoam so as not to allow contact with the object and the metal sides.  Then, voila !  I had an inexpensive, and most likely effective Faraday cage.  I later secured the lid with a little duct tape.  In the years which followed I placed a reserve insulin pump in there, a solar radio, a couple of different blood glucose monitors, and a portable pulse oximeter.  We were well prepared and our electronics were protected.
            In the years since there have been discussions of a number of nations having cultivated and created an electro-pulse weapon designed to disable the enemy's communication and possibly travel devices also.  I remember when President Clinton's helicopter crashed killing the crew aboard, rumors of an EMP weapon which was being tested by a Maryland contractor.  Would my Faraday cage protect the electronics stored there ?
            EMPs are not all the same.  The type of energy from which the EMP originates can differ.  They can be negative or regular pulse trains. They can be natural or unnatural pulses. They can have varying frequency ranges, and differing pulse waveforms.   Thinking of an EMP as one entity is a lot like considering all earthquakes to be the same.  Each event can be unique.
             There are natural EMP events.  One would include a lightning strike. We all know how badly lightning can damage anything electronic, and for that matter, I personally can attest to what damage it can do to human beings and to animals. Another one can be an electrostatic discharge.  We've all shocked ourselves walking across a carpet and then touching a doorknob.   Such a shock can be dangerous to a patient with an intravenous line or those who are critically ill.  Few people realize that a natural electrostatic shock can wipe out the programming of an insulin pump, causing the basal and bolus features to need to be reprogrammed entirely.  
             Unnatural or man-made EMPs can be caused by, as I mentioned prior, a nuclear bomb. This would normally be a fairly local phenomenon, however a high altitude nuclear detonation, could wipe out all of the electronics for a rather broad area.  This application probably has great weapons potential and the abatement of such has likely been the focus of our military.  There is also the EMP weapon which is suspected to be within the arsenal of the US, France, England, China, Russia, and probably other nations as well.    Other types of low impedence EMP interference can also be man-made.  These would include the types of EMP generated inadvertently from other electrical activities.   Relays, solenoids, and other devices generate some EMP.  Electric motors cause a train of disruption when they run.  Power line surges can also generate EMP.
            The point is that one EMP is not like another.  We cannot completely predict the effect an EMP might have on a particular piece of electronics.   There is also a considerable amount of pop culture lore on EMP weaponry which interferes with the public's ability to understand and appropriately shield for it.
            The best that most of us can do is create a Faraday cage for essential back up electronic devices.  An inexpensive cellular phone might be a good idea to place in there also, despite the fact that the cellular towers could be damaged from an event and be disabled.   I know others who have shielded the interior of garages and even basements.   I know still others who store essential electronics in non-functional microwave ovens for safekeeping.
            Although this is a consideration in preparedness, make sure that you have adequate water, food, tools, medicines, and have anchored heavy objects so that they do not fall on people during an earthquake.  Make sure that you have planned FIRST for the disasters which are most likely in your region.  We can speculate and anticipate EMPs afterward.

More information on EMP and protective measures:






mohave rat said...

this is an excellent post! Imagine on EMP burst of sufficient strength and every car and truck in America with an electronic ignition would be useless. A real threat well worth planning for! the rat

Gorges Smythe said...

Walkie-talkies might do you more good than a cell phone, though BOTH would be better. And I hadn't thought about a trash can!

JaneofVirginia said...

Thanks Mr. Rat, If one is building a garage it is not expensive to shield the inside. A car would be protected if it happened to be home when an EMP was discharged. It is a concern worth considering.

JaneofVirginia said...

Yes, we use walkie talkies here on the farm. They are very helpful and can be set to encrypt your communication which is also an excellent feature.

russell1200 said...

The evidence for EMP effects from a high altitude nuclear strike are very weak, and the test data does not indicate a general destruction of electronics as is generally claimed. As best I can tell, the very popular novel (for its day) Warday, brought in the modern concept of EMP, and everyone seems to be copying it. The problem with making an EMP work, is much the same problem you have with making dirty bombs work. The size of an effective blast is worse than the secondary issues.

The evidence for the damage done by a solar flare (for which we have a much better historical record), which has much more energy than a nuclear weapon, is very strong.

Lighting is not EMP. Lightning, is the actual movement of electrons through conductive materials: or at least conductive at very high voltages. EMP is more like a very powerful radio transmission that gets picked up by various antenna and is turned into an electrical impulse. If the initiating signal is strong enough, and the conductor is long enough, a lot of energy can be involve.

EMP is odd enough stuff, that I will grant there are unknowns. But it would be more compelling if people without an agenda would stop pushing the same, very thin, and mostly anecdotal research. The government research that gets published now (at the One Second After site for instance) had the appendix, that did not agree sync with the electronics issues, removed. Buy if you look closely at the main body, you can still see in their findings, what the research actually said. For instance, all cards "EMPed" that were turned off, where able to turn back on once the effect was over. Of the trucks (I think there were only 5) all but one restarted.

JaneofVirginia said...

Thanks Russell for the added information. Then you would be in agreement with my point which is that we should prepare FIRST for the natural or man-made disasters which are most likely to occur in our area, and then turn our attention to protecting some electronics in a Faraday cage afterward ?

JaneofVirginia said...

No lightning strikes are not EMP, however, when an area is struck by lightning, electronic items that were not struck and would not appear to be in the strike field often do not work as they did before. There has been some disruption of the electromagnetic fields in the region. This is why lightning is discussed within the context of EMP in this and in many other articles. http://en.wikipedia.org/wiki/Electromagnetic_pulse

Sandy said...

A faraday cage will help your electronics if built correctly.

Another good form of communication would be using ham radios.

JaneofVirginia said...

Yes, I have a Yaesu, but I have not yet been licensed to use it. The walkie talkies are helpful with the neighboring farm and also with the family. The walkies actually work better there than the cellphones.

BBC said...

Rolls eyes, if the shit hits the fan I'm pretty sure I could care less about communicating with anyone else other than those around me that can hear me when I'm talking. And if it is that bad I won't be needing to drive anywhere anyway. Unless I go somewhere on one of my bikes.

Wait, I have an old Toro riding mower that wouldn't be affected by something like that and it's powerful enough to pull my survival gear trailer, hahahahaha