Understanding EMP Threats and How to Prepare
An EMP, or electromagnetic pulse, is a sudden burst of electromagnetic energy that can damage or destroy the power grid and quietly wipe out unprotected electronic devices and systems in its path. An EMP can be caused by natural phenomena, such as solar flares or geomagnetic storms, or by human-made sources, such as nuclear weapons or specialized devices. An EMP can have devastating effects on modern society, especially if it targets critical infrastructure and communication networks.
Electromagnetic Pulse: Causes & Factors
EMP Causes
A CME is a natural phenomenon caused by solar flare activity interacting with Earth's magnetic field. This can disrupt power grids, damage transformers, and cause communication blackouts. A notable example is the 1989 Quebec blackout, where a geomagnetic storm caused by a CME left millions without power.
A man-made nuclear detonation at high altitude can cause widespread severe damage to the power grid. Though nuclear EMP does not produce radioactive fallout on the ground in high-altitude bursts, its ability to impact critical infrastructure and technology across vast regions makes it a significant threat.
EMP Factors
The pulse expands in a roughly circular pattern from the point of detonation so, at higher altitude, a detonation can have a line of sight to a larger portion of the earth’s surface, thereby affecting a larger area.
The intensity of the EMP (how strong the pulse is) at a specific location on the ground also depends on the yield of the explosion (how big the explosion is) and the design of the weapon.
About EMPs
If a high-altitude nuclear EMP occurs, there would likely not be an immediate public alert issued, whereas significant solar events may be predicted or tracked by space-weather agencies, giving you a heads up on the possibility of a potential solar storm strike. If you are left to figure it out on your own, recognizing the immediate signs can help you evaluate what’s happening so you can swing into action (see plan of action below).
Immediate Signs of an EMP
- Sudden power outages across affected areas.
- Electronic devices stop functioning, including phones, laptops, and other wireless devices.
- Disruption of communication networks and broadcasting stations (e.g., radio and TV signals cease).
- Cars with microchips and integrated circuits may experience malfunctions or fail to start.
- Failure of electrical infrastructure, like lighting systems or traffic signals.
- Airplanes and helicopters could experience disruptions to their electronic systems, leading to potential risks during flights.
Risks and Challenges to EMP Recovery
- Prolonged power outages affecting daily life and economic activities.
- Disruption of critical infrastructure, including water supply, healthcare, and transportation systems.
- Damage to or destruction of unshielded electronic devices and systems, hindering recovery efforts.
- Reduced communication capabilities, isolating individuals and organizations from timely information and coordination.
- Food and water scarcity due to impacts on supply chains and refrigeration systems.
- Increased societal vulnerability to health crises and crime due to lack of resources and services.
- Challenges in restoring the power grid and damaged infrastructure, potentially taking weeks, months, or longer.
Before an EMP Happens
A massive power grid failure will cause major disruption and life-altering challenges. However, there are things you can do today to help mitigate the devastating effects of a potential long-term power outage.
#1 Supplies to have on hand
The best way to prepare for an EMP is by having enough supplies to see your through what could be a substantial amount of time without electricity. Check out prepare your home for ideas on ways to shore up your home supply. Here are some of the supplies covered:
#2 Family Plans and Helpful Kits
- Family Communications - A family communication plan gives everyone a backup way to reconnect when the power goes out and normal methods stop working. It cuts down on confusion and helps everyone know where to go and what to do.
- Home Security - A home security plan helps you protect your house even when alarms, cameras, and basic lighting fail. Having a clear plan ahead of time keeps you safer and reduces panic.
- Away From Home Plan - An away from home plan helps you handle emergencies at places you visit often, like work, school, or a relative’s house. It gives you a clear idea of what to do if the grid goes down while you’re not home.
- Away from Home Kits - If you’re at work, school, or on the road when an EMP hits, these kits give you immediate access to food, water, and other essentials. They help you shelter in place or stay safe until you can move.
- Get Back Home Kit - A get back home kit gives you what you need to walk home safely if your car or public transportation stops working. It turns a stressful situation into something you can manage with confidence.
- Cash on Hand - Having cash on hand keeps you functioning when ATMs are down and stores can only take cash. It lets you buy what you need without relying on electronic systems that may be offline.
#3 Faraday Cage
A Faraday cage is a hollow conductive enclosure that shields its contents from any incoming electromagnetic fields because the charge remains solely on its external surface. Protection comes in the form of either a cage or bag. They come in different sizes and materials and are both effective at blocking electromagnetic fields.
- Faraday Cage: This is either a solid or mesh structure of rigid conductive material that can be portable or stationary.
- Faraday Bag: This is a flexible, portable bag made of conductive textiles that is meant mostly for the protection of portable electronic equipment. Some are bigger and can house larger objects.
#4 Items to protect
The goal is to protect items and equipment that are essential to survival and communications. Anything that uses a circuit board, microchip, or digital controller is vulnerable; anything rechargeable almost always contains circuitry; and anything that communicates, navigates, or processes information relies on electronics internally.
Communication & Navigation
- Communication Devices: Phones, walkie-talkies, and satellite phones.
- Radio Equipment: Emergency radios (hand-crank or solar) and Ham/GMRS radios.
- Navigation: GPS units and compasses featuring digital sensors
Medical & Assistive Tech
- Medical Equipment: Glucose meters, portable nebulizers, digital thermometers, blood pressure cuffs, and CPAP machines.
- Assistive Devices: Hearing aids and cochlear implant processors. (Note: Keep spare batteries for these items in the cage as well).
Power & Lighting
- Power Banks & Chargers: Portable USB battery banks and small portable solar panels.
- Flashlights: Rechargeable flashlights and headlamps.
- Batteries: Standard batteries and, more importantly, extra rechargeable batteries (Li-ion, NiMH, etc.).
- Generators: While large whole-home systems require hardwired protection, small inverter generators can often be safely stored in large, heavy-duty military-grade Faraday bags or custom-built metal containers.
Data & Information
- Computing Devices: Laptops and tablets.
- Storage Media: External hard drives, solid-state drives (SSDs), and USB flash drives containing vital documents, maps, and offline backups.
- Networking: Backup routers or modems.
Everyday Essentials
- Vehicle Key Fobs: Smart keys for push-to-start vehicles.
Key Considerations for Storage
- Nested Protection: For maximum protection, you can nest containers - wrap items in anti-static or non-conductive materials (like bubble wrap or cardboard), then wrap in aluminum foil, and place the layers inside a certified bag or sturdy metal container (like an ammo can or steel trash can).
- Standards: Ensure your Faraday bags or containers meet MIL-STD 188-125 standards for electromagnetic shielding.
- Powered Off: Never store devices turned on or physically connected to external wiring while inside the cage
Tip: Spend a weekend without electricity and see how well-prepared you are. Use the experience to help you better prepare not only with supplies you may have overlooked, but mentally and emotionally as well.
After an EMP
Unlike many disasters, there is no direct sign of an EMP explosion itself. It typically occurs at high altitude, which can make it hard to see; however, some observers may notice a flash, depending on conditions. You may be left to look around and put two and two together to determine that an EMP has taken place. Likely signs are listed above.
#1 First 10 Minutes
Because you have taken the time to recognize the signs of an EMP, you will know what’s happening - most people will freeze in confusion. You won’t. Once you fell confident that this is the case, move immediately.
Unplug All Devices & Appliances
- Turn off and unplug all electronics.
- This may prevent additional damage from secondary surges.
- Keep everything unplugged until the danger has passed.
Check for Electrical Fires
- Walk through your home and check outlets, appliances, and the breaker panel.
- Look for smoke, burning smells, or scorch marks.
- Keep the fire extinguisher ready.
Gather Water
- The water pressure could weaken rapidly and eventually stop flowing - gather water quickly before this happens.
- Fill every sink, pot, glass, and container.
- Fill bathtubs using a WaterBob or similar liner.
- In multi-story buildings, water may fail within minutes.
Attempt to Start Your Vehicle
- Try starting your car right away.
- If it runs, park it safely and conserve it.
- If it doesn’t, assume it will remain inoperable.
#2 First Hour
Once the immediate scramble of the first few minutes is behind you, the next hour is about stabilizing your home, protecting your resources, and getting ahead of the chaos that will unfold outside. This is when you shift from urgent actions to deliberate ones.
Gather Your Family
- Bring all family members together.
- If someone is away and towers aren’t working, initiate your communication plan immediately. This includes alternative communication strategies.
- Check on elderly or medically fragile neighbors.
Spend Your Cash
- Make a run to the store for additional supplies.
- Stores may accept cash until shelves are empty.
- Focus on shelf stable food, water, hygiene items, and medical supplies.
- Get in and out quickly - crowds will grow fast.
Secure Your Home
- Lock all doors and windows.
- Close blinds and curtains to prevent visibility from outside.
- Reinforce entry points if needed.
Establish Light & Noise Discipline
- Use your generator sparingly and never light up your home.
- Avoid grilling or cooking outside - smells travel far.
- Keep noise to a minimum, especially after dark.
Assess Medical Needs
- Gather all prescription medications.
- Prioritize refrigeration-dependent meds while the fridge is still cold.
- Create a plan for anyone with chronic conditions or medical devices.
Set Up Sanitation
- Fill buckets for manual toilet flushing while water still flows.
- Prepare a backup waste system using trash bags, cat litter, or sawdust.
- Keep waste sealed and away from living areas.
Get Your Alternate Fuel & Devices
- Get your alternative fuel, lighting and cooking devices, like lanterns, stoves, heaters, and other non electric tools.
- Prepare mentally for the shift to low-tech living.
Get Your Alternate Communication Devices
- Bring out your alternative communication devices, like walkie-talkies, CB, ham, or push-to-talk over cellular radios.
- Prepare mentally for the shift to minimal communication to the outside world.
Gather Information
- Use a hand-crank or battery-powered radio stored in Faraday protection.
- Begin a written log of events, conditions, and supply usage.
Protect Your Supplies
- Hide or decentralize your supplies within your home.
- Keep only minimal items visible in common areas.
#3 First Day
Things may become chaotic very quickly outside your front door, but things will also change dramatically in your home. Don't worry, you have prepared. However, there are some things you can do and also avoid that will help your family better deal with a long-term power outage.
Stay Inside and Avoid Crowds
- Stay away from busy streets, stores, and gathering points.
- Early chaos and increased foot traffic are common after major grid failures.
Assign Household Roles
- Divide responsibilities: water, security, cooking, sanitation, childcare.
- Establish quiet hours and routines to keep everyone calm and focused.
Use Perishable Food First
- Eat what’s in your refrigerator first, then your freezer.
- Transition to shelf-stable food once perishables are gone.
Maintain a Low Profile
- Keep lights dim and contained.
- Avoid smells, noise, and visible activity that signal preparedness.
- Expect increased movement through neighborhoods as people search for resources.
Continue Monitoring Conditions
- Check your radio periodically.
- Update your written log.
- Reassess supplies and adjust rationing as needed.