Plan & Prepare

Photo of earthquake damage to a home

Earthquakes are the rumblings, shaking or rolling of the earth's surface caused by the sudden breaking and movement of large sections of the earth's rocky outermost crust. This sudden release of energy causes the seismic waves that make the ground shake. They can be felt over large areas and may last only a few seconds or may continue for up to several minutes.

Scientists have tried many ways to predict when an earthquake will occur, but none have been successful and it is unlikely that they ever will.

Show All Sections

Basic Preparedness

  • Prepare yourself and your family by creating an Emergency Supply Kit and a Family Disaster Plan. See NJOEM's Basic Preparedness page for more details.
    • Your Kit includes items that will help you stay self-sufficient for up to three days, if needed.
    • Your Plan includes evacuation plans, a place to reunite with loved ones, and an out-of-state contact person.
  • Know the "Safe Spots" in your home. Places that are best are under sturdy furniture like a heavy table or desk and against inside walls.
  • Know the "Danger Spots" as well. Stay away from glass that might shatter (windows, mirror, pictures) or where heavy furniture like bookcases could fall.
  • If you're outside, locate places outdoors away from buildings, trees, telephone and electrical lines, overpasses, or elevated roadways.
  • An Earthquake Safety Checklist provided by FEMA that features instructions on conducting earthquake drills and “hazard hunts.” Also included are a checklist of disaster supplies, tips on what to do during and after an earthquake, and additional resources.

Prepare Your Home

  • Secure any objects that can be identified as a hazard paying particular attention to tall, heavy, or expensive objects such as bookcases and home electronics.
  • Keep breakable and heavy objects on lower shelves.
  • Secure water heaters and appliances that could move enough to rupture utility lines.
  • Secure hanging plants and heavy picture frames or mirrors (especially those hanging over beds).
  • Learn how to turn off the gas, electricity, and water at valves and main switches. Consult your local utilities if you need more information.
  • Check chimneys, roofs, and wall foundations for stability.
  • Keep pesticides, herbicides and flammable items in closed, latched cabinets on bottom shelves.

If You Are Indoors:

  • Drop, Cover, and Hold On. Drop to the floor, take cover under a sturdy desk or table, and hold on to it firmly. Be prepared to move with it until the shaking stops. If you are not near a desk or table, drop to the floor against the interior wall and protect your head and neck with your arms. Avoid exterior walls, windows, hanging objects, mirrors, tall furniture, large appliances, and kitchen cabinets with heavy objects or glass. Do not go outside! Stay in the building unless it is clearly unsafe, or you are told to leave. Leaving a building during the shaking of an earthquake is very dangerous because objects can fall on you.
  • If you are in bed:
    • Hold on and stay there. Use a pillow to protect your heaed. You are less likely to be injured staying where you are. Broken glass on the floor has caused injury to those who have rolled to the floor or tried to get to doorways.
  • If you use a wheelchair:
    • Try to get under a doorway or into an inside corner, lock the wheels and cover your head with your arms. Remove any items that are not securely attached to the wheelchair.
  • If you are in a high-rise:
    • Drop, Cover, and Hold On. Avoid windows and other hazards. Use stairs. Elevators may lose power or fall. Do not be surprised if sprinkler systems or fire alarms activate.
  • In a stadium or theater:
    • Stay at your seat and protect your head and neck with your arms. Don't try to leave until the shaking is over. Then walk out slowly watching for anything that could fall in the aftershocks.
  • Near the shore:
    • Drop, Cover, and Hold On until the shaking stops. Estimate how long the shaking lasts. If severe shaking lasts 20 seconds or more, immediately evacuate to high ground as a tsunami might have been generated by the earthquake. Move inland 3 kilometers (2 miles) or to land that is at least 30 meters (100 feet) above sea level immediately. Don't wait for officials to issue a warning. Walk quickly, rather than drive, to avoid traffic, debris and other hazards.

If Outdoors:

  • Locate places outdoors away from buildings, trees, telephone and electrical lines, overpasses, or elevated roadways.

If Driving:

  • Drive to (or stay in) open areas away from danger of falling objects, power lines, etc.
  • Vacate bridges, tunnels and underpasses.
  • Watch traffic, other drivers may be disoriented, or out of control.
  • Once in an open area, stay in your car.

The moment the ground stops shaking.

  • Expect and prepare for potential aftershocks. They cause additional damage and can collapse weakened structures. Remember to “Drop, Cover, and Hold on”.
  • If you live in a coastal area be aware of possible tsunamis. If local authorities issue a tsunami warning move to higher ground as soon as you can safely do so.
  • Check yourself for injuries and get First Aid, if necessary, before helping injured or trapped persons.
  • Look quickly for damage in and around your home such as leaking gas lines, damage to the building, water or electric lines, or other things that may be dangerous. Look for and extinguish small fires if possible. If your home is unsafe get everyone out.
  • Check for gas leaks. If you smell gas or hear a blowing or hissing noise, open a window and quickly leave the building. Turn off the gas at the main valve if you can and call the gas company from a neighbor's home. If you turn off the gas for any reason, it must be turned back on by a professional.
    • Do not flip an electric switch. It can cause sparks that will trigger explosions around gas leaks, as will cigarettes, candles and matches.
  • Look for electrical system damage. If you see sparks or broken or frayed wires, or if you smell hot insulation, turn off the electricity at the main fuse box or circuit breaker if you can.
  • Check for sewage and water line damage. If you suspect sewage lines are damaged, avoid using toilets and call a plumber. If water pipes are damaged, contact the water company and avoid using water from the tap. You can obtain safe water by melting ice cubes.
  • If you turn off a utility-main after a disaster, only the utility company is allowed to turn it on again -- after they have determined it is safe. This may leave you without heat or light for several days.
  • Water can be obtained from canned vegetables, melted frozen foods or ice, hot-water-heater drain valves (even if water main is off), and from toilet tanks (not bowls).
  • Listen to a radio if possible for public announcements and alerts.
  • Check on neighbors who may require special assistance - infants, elderly people and people with disabilities.
  • Phone service may be out. Use the telephone only for emergency calls. When possible, text or call your out-of-area contact and tell them where you are.
  • Stay out of damaged buildings. Return home only when authorities say it is safe.
  • Watch out for fallen power lines and report them immediately. Reporting potential hazards will get the utilities turned off as quickly as possible, preventing further hazard and injury.
  • Clean up spilled medicines, bleaches, or gasoline or other flammable liquids.
  • Clean up broken glass and other debris.
  • Keep your pets safe and in your control.
  • If you are trapped:
    • Do not light a match.
    • Do not move about or kick up dust.
    • Protect your mouth, nose, and eyes from dust
    • Tap on a pipe or wall or use a whistle, if you have one, so that rescuers can locate you.
  • Let your family and people you know you're safe.
  • Take pictures of the damage - both to the house and its contents - for insurance purposes.

An earthquake can be measured by the amount of energy released. The Richter scale uses Arabic numbers to rate the amount of energy, or its magnitude.

The size or strength of an earthquake may be measured by the intensity or kind of damage that occurs. Intensity depends on your distance from the epicenter and the geologic area. The Modified Mercalli scale measures the earthquake’s effect on people, property and ground damage. Roman numerals are used to rate the intensity and damage.

An earthquake may have a different intensity rating at different locations. Damage is usually lessened with distance from the earthquake’s epicenter. However, damage may depend on the type of structure, construction, or type of soil on which the structure was built. For example, a building on bedrock experiences less movement than a building on loose sediments.

While the Richter scale describes the earthquake's magnitude by measuring the seismic waves generated by the earthquake, the Mercalli scale describes the intensity based on its observed effects.

The Modified Mercalli (MM) scale reads as follows:

  1. Not felt except by a very few under especially favorable circumstances.
  2. People lying down might feel the earthquake. Light suspended objects may sway.
  3. People on upper floors will feel it, but may not know it’s an earthquake. Hanging objects swing.
  4. People indoors will probably feel it, but those outside may not. Houses may creak.
  5. Nearly everybody feels it. Sleepers are awakened. Doors swing, pictures move, things tip over.
  6. Everyone feels the earthquake. It is hard to walk. Windows and dishes broken. Books fall from shelves.
  7. It is hard to stand. Plaster, bricks and tiles fall from buildings. Small landslides.
  8. People will not be able dive cars. Poorly built buildings may collapse, chimneys may fall.
  9. Most foundations are damaged. Masonry heavily damaged. Pipes are broken. The ground cracks.
  10. Most buildings are destroyed. Water is thrown out of rivers and lakes. Large landslides.
  11. Rails are bent. Bridges and underground pipelines unusable.
  12. Most objects are leveled. Large objects may be thrown into the air. Large rock masses displaced.

Approximate Relationship Between Magnitude and Intensity

Magnitude Felt Area
(Square miles)
Distance Felt
(approx. miles)
Modified Mercalli Scale
(close to epicenter)
3.0-3.9 750 15 I-III
4.0-4.9 3,000 30 IV-V
5.0-5.9 15,000 70 VI-VII
6.0-6.9 50,000 125 VII-VIII
7.0-7.9 200,000 250 IX-X