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Some Common Natural Hazards
View of tsunami waves hitting a shoreline.

Tsunamis (pronounced soo-ná-mees), also known as seismic sea waves (mistakenly called “tidal waves”), are a series of enormous waves created by an underwater disturbance such as an earthquake, landslide, volcanic eruption, or meteorite. A tsunami can move hundreds of miles per hour in the open ocean and smash into land with waves as high as 100 feet or more.

From the area where the tsunami originates, waves travel outward in all directions. Once the wave approaches the shore, it builds in height. The topography of the coastline and the ocean floor will influence the size of the wave. There may be more than one wave and the succeeding one may be larger than the one before. That is why a small tsunami at one beach can be a giant wave a few miles away.

All tsunamis are potentially dangerous, even though they may not damage every coastline they strike. A tsunami can strike anywhere along most of the U.S. coastline. The most destructive tsunamis have occurred along the coasts of California, Oregon, Washington, Alaska and Hawaii.

Earthquake-induced movement of the ocean floor most often generates tsunamis. If a major earthquake or landslide occurs close to shore, the first wave in a series could reach the beach in a few minutes, even before a warning is issued. Areas are at greater risk if they are less than 25 feet above sea level and within a mile of the shoreline. Drowning is the most common cause of death associated with a tsunami. Tsunami waves and the receding water are very destructive to structures in the run-up zone. Other hazards include flooding, contamination of drinking water, and fires from gas lines or ruptured tanks.

Wreckage after a tsunamiBefore a Tsunami

The following are things you can do to protect yourself, your family and your property from the effects of a tsunami:

  • To begin preparing, you should build an emergency kit and make a family communications plan.
    • Talk to everyone in your household about what to do if a tsunami occurs. Create and practice an evacuation plan for your family. Familiarity may save your life. Be able to follow your escape route at night and during inclement weather. You should be able to reach your safe location on foot within 15 minutes. Practicing your plan makes the appropriate response more of a reaction, requiring less thinking during an actual emergency.
    • If the school evacuation plan requires you to pick your children up from school or from another location. Be aware telephone lines during a tsunami watch or warning may be overloaded and routes to and from schools may be jammed.
    • Knowing your community's warning systems and disaster plans, including evacuation routes.
  • Know the height of your street above sea level and the distance of your street from the coast or other high-risk waters. Evacuation orders may be based on these numbers.
  • If you are a tourist, familiarize yourself with local tsunami evacuation protocols. You may be able to safely evacuate to the third floor and higher in reinforced concrete hotel structures.
  • If an earthquake occurs and you are in a coastal area, turn on your radio to learn if there is a tsunami warning.
Know the Terms

Familiarize yourself with these terms to help identify a tsunami hazard:


A tsunami warning is issued when a tsunami with the potential to generate widespread inundation is imminent or expected. Warnings alert the public that dangerous coastal flooding accompanied by powerful cur­rents is possible and may continue for several hours after initial arrival. Warnings alert emergency management officials to take action for the entire tsunami hazard zone. Appropriate actions to be taken by local officials may include the evacuation of low-lying coastal areas, and the repositioning of ships to deep waters when there is time to safely do so. Warnings may be updated, adjusted geographically, downgraded, or canceled. To provide the earliest possible alert, initial warnings are normally based only on seismic information.


A tsunami advisory is issued when a tsunami with the potential to generate strong currents or waves dangerous to those in or very near the water is imminent or expected. The threat may continue for sev­eral hours after initial arrival, but significant inundation is not expected for areas under an advisory. Appropriate actions to be taken by local officials may include closing beaches, evacuating harbors and marinas, and the repositioning of ships to deep waters when there is time to safely do so. Advisories are normally updated to continue the advisory, expand/contract affected areas, upgrade to a warning, or cancel the advisory.


A tsunami watch is issued to alert emergency management officials and the public of an event which may later impact the watch area. The watch area may be upgraded to a warning or advisory - or canceled - based on updated information and analysis. Therefore, emergency management officials and the public should prepare to take action. Watches are normally issued based on seismic information without confirmation that a destructive tsunami is underway.

Information Statement

A tsunami information statement is issued to inform emergency manage­ment officials and the public that an earthquake has occurred, or that a tsunami warning, watch or advisory has been issued for another section of the ocean. In most cases, information statements are issued to indicate there is no threat of a destructive tsunami and to prevent unnecessary evacuations as the earthquake may have been felt in coastal areas. An information statement may, in appropriate situations, caution about the possibility of destructive local tsunamis. Information statements may be re-issued with additional information, though normally these messages are not updated. However, a watch, advisory or warning may be issued for the area, if necessary, after analysis and/or updated information becomes available.

During a Tsunami

  • Follow the evacuation order issued by authorities and evacuate immediately. Take your animals with you.
  • Move inland to higher ground immediately. Pick areas 100 feet (30 meters) above sea level or go as far as 2 miles (3 kilometers) inland, away from the coastline. If you cannot get this high or far, go as high or far as you can. Every foot inland or upward may make a difference.
  • Stay away from the beach. Never go down to the beach to watch a tsunami come in. If you can see the wave you are too close to escape it. CAUTION - If there is noticeable recession in water away from the shoreline this is nature's tsunami warning and it should be heeded. You should move away immediately.
  • Save yourself - not your possessions.
  • Remember to help your neighbors who may require special assistance - infants, elderly people, and individuals with access or functional needs.

After a Tsunami

  • Return home only after local officials tell you it is safe. A tsunami is a series of waves that may continue for hours. Do not assume that after one wave the danger is over. The next wave may be larger than the first one.
  • Go to a designated public shelter if you have been told to evacuate or you feel it is unsafe to remain in your home. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example: shelter 12345).
  • Avoid disaster areas. Your presence might interfere with emergency response operations and put you at further risk from the residual effects of floods.
  • Stay away from debris in the water; it may pose a safety hazard to people or pets.
  • Check yourself for injuries and get first aid as needed before helping injured or trapped persons.
  • If someone needs to be rescued, call professionals with the right equipment to help. Many people have been killed or injured trying to rescue others.
  • Help people who require special assistance—infants, elderly people, those without transportation, people with access and functional needs and large families who may need additional help in an emergency situation.
  • Continue using a NOAA Weather Radio or tuning to a Coast Guard station or a local radio or television station for the latest updates.
  • Stay out of any building that has water around it. Tsunami water can cause floors to crack or walls to collapse.
  • Use caution when re-entering buildings or homes. Tsunami-driven floodwater may have damaged buildings where you least expect it. Carefully watch every step you take.
  • To avoid injury, wear protective clothing and be cautious when cleaning up.

Related Websites

Find additional information on how to plan and prepare for a tsunami and learn about available resources by visiting the following websites:

Listen to Local Officials

Learn about the emergency plans that have been established in your area by your state and local government. In any emergency, always listen to the instructions given by local emergency management officials.

Hurricane in the Gulf of Mexico seen from space.

This page explains what actions to take when you receive a hurricane watch or warning alert from the National Weather Service for your local area. It also provides tips on what to do before, during, and after a hurricane.

Basic Preparedness Tips

  • Know where to go. If you are ordered to evacuate, know the local hurricane evacuation route(s) to take and have a plan for where you can stay. Contact your local emergency management agency for more information.
  • Put together a disaster supply kit, including a flashlight, batteries, cash, first aid supplies, and copies of your critical information if you need to evacuate
  • If you are not in an area that is advised to evacuate and you decide to stay in your home, plan for adequate supplies in case you lose power and water for several days and you are not able to leave due to flooding or blocked roads.
  • Make a family emergency communication plan.
  • Many communities have text or email alerting systems for emergency notifications.To find out what alerts are available in your area, search the Internet with your town, city, or county name and the word “alerts.”

Preparing Your Home

  • Hurricane winds can cause trees and branches to fall, so before hurricane season trim or remove damaged trees and limbs to keep you and your property safe.
  • Secure loose rain gutters and downspouts and clear any clogged areas or debris to prevent water damage to your property.
  • Reduce property damage by retrofitting to secure and reinforce the roof, windows and doors, including the garage doors.
  • Purchase a portable generator or install a generator for use during power outages. Remember to keep generators and other alternate power/heat sources outside, at least 20 feet away from windows and doors and protected from moisture; and NEVER try to power the house wiring by plugging a generator into a wall outlet.
  • Consider building a FEMA safe room or ICC 500 storm shelter designed for protection from high-winds and in locations above flooding levels.  

Hurricane Watch

Hurricane watch = conditions possible within the next 48 hrs.

Steps to take:

Hurricane Warning

Hurricane warning = conditions are expected within 36 hrs.

Steps to take:

  • Follow evacuation orders from local officials, if given.
  • Check-in with family and friends by texting or using social media.
  • Follow the hurricane timeline preparedness checklist, depending on when the storm is anticipated to hit and the impact that is projected for your location.

What to do when a hurricane is 6 hours from arriving

  • If you’re not in an area that is recommended for evacuation, plan to stay at home or where you are and let friends and family know where you are.
  • Close storm shutters, and stay away from windows. Flying glass from broken windows could injure you.
  • Turn your refrigerator or freezer to the coldest setting and open only when necessary. If you lose power, food will last longer. Keep a thermometer in the refrigerator to be able to check the food temperature when the power is restored.
  • Turn on your TV/radio, or check your city/county website every 30 minutes in order to get the latest weather updates and emergency instructions.

What to do when a hurricane is 6-18 hours from arriving

  • Turn on your TV/radio, or check your city/county website every 30 minutes in order to get the latest weather updates and emergency instructions.
  • Charge your cell phone now so you will have a full battery in case you lose power.

What to do when a hurricane is 18-36 hours from arriving

  • Bookmark your city or county website for quick access to storm updates and emergency instructions.
  • Bring loose, lightweight objects inside that could become projectiles in high winds (e.g., patio furniture, garbage cans); anchor objects that would be unsafe to bring inside (e.g., propane tanks); and trim or remove trees close enough to fall on the building.
  • Cover all of your home’s windows. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” exterior grade or marine plywood, cut to fit and ready to install.

What to do when a hurricane is 36 hours from arriving

  • Turn on your TV or radio in order to get the latest weather updates and emergency instructions.
  • Build or restock your emergency preparedness kit. Include a flashlight, batteries, cash, and first aid supplies.
  • Plan how to communicate with family members if you lose power. For example, you can call, text, email or use social media. Remember that during disasters, sending text messages is usually reliable and faster than making phone calls because phone lines are often overloaded.
  • Review your evacuation plan with your family. You may have to leave quickly so plan ahead.
  • Keep your car in good working condition, and keep the gas tank full; stock your vehicle with emergency supplies and a change of clothes.

After a Hurricane

  • Listen to local officials for updates and instructions.
  • Check-in with family and friends by texting or using social media.
  • Return home only when authorities indicate it is safe.
  • Watch out for debris and downed power lines.
  • Avoid walking or driving through flood waters. Just 6 inches of moving water can knock you down, and fast-moving water can sweep your vehicle away.
  • Avoid flood water as it may be electrically charged from underground or downed power lines and may hide dangerous debris or places where the ground is washed away.
  • Photograph the damage to your property in order to assist in filing an insurance claim.
  • Do what you can to prevent further damage to your property, (e.g., putting a tarp on a damaged roof), as insurance may not cover additional damage that occurs after the storm.

When there is no hurricane: Make a hurricane plan

  • Know your hurricane risk. Talk to your local emergency management agency.
  • Make an emergency plan.
  • Build or restock your basic disaster supplies kit, including food and water, a flashlight, batteries, chargers, cash, and first aid supplies.
  • Consider buying flood insurance.
  • Familiarize yourself with local emergency plans. Know where to go and how to get there should you need to get to higher ground or to evacuate.
  • Stay tuned to local wireless emergency alerts, TV, or radio for weather updates, emergency instructions, or evacuation orders.

Community Events

View of a dead tree and fence row in a summer sunset.

Heat kills by pushing the human body beyond its limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.

Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children and those who are sick or overweight are more likely to succumb to extreme heat.

Conditions that can induce heat-related illnesses include stagnant atmospheric conditions and poor air quality. Consequently, people living in urban areas may be at greater risk from the effects of a prolonged heat wave than those living in rural areas. Also, asphalt and concrete store heat longer and gradually release heat at night, which can produce higher nighttime temperatures known as the "urban heat island effect."

A heat wave is an extended period of extreme heat, and is often accompanied by high humidity. These conditions can be dangerous and even life-threatening for humans who don't take the proper precautions.

Boy drinking bottled waterBefore Extreme Heat

To prepare for extreme heat, you should:

  • To begin preparing, you should build an emergency kit and make a family communications plan.
  • Install window air conditioners snugly; insulate if necessary.
  • Check air-conditioning ducts for proper insulation.
  • Install temporary window reflectors (for use between windows and drapes), such as aluminum foil-covered cardboard, to reflect heat back outside.
  • Weather-strip doors and sills to keep cool air in.
  • Cover windows that receive morning or afternoon sun with drapes, shades, awnings, or louvers. (Outdoor awnings or louvers can reduce the heat that enters a home by up to 80 percent.)
  • Keep storm windows up all year.
  • Listen to local weather forecasts and stay aware of upcoming temperature changes.
  • Know those in your neighborhood who are elderly, young, sick or overweight. They are more likely to become victims of excessive heat and may need help.
  • Be aware that people living in urban areas may be at greater risk from the effects of a prolonged heat wave than are people living in rural areas.
  • Get trained in first aid to learn how to treat heat-related emergencies.
Know the Terms

Familiarize yourself with these terms to help identify an extreme heat hazard:

Heat Wave - Prolonged period of excessive heat, often combined with excessive humidity.

Heat Index - A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.

Heat Cramps - Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.

Heat Exhaustion - Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim's condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.

Heat Stroke - A life-threatening condition. The victim's temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.

Sun Stroke - Another term for heat stroke.

Excessive Heat Watch - Conditions are favorable for an excessive heat event to meet or exceed local Excessive Heat Warning criteria in the next 24 to 72 hours.

Excessive Heat Warning - Heat Index values are forecast to meet or exceed locally defined warning criteria for at least 2 days (daytime highs=105-110° Fahrenheit).

Heat Advisory - Heat Index values are forecast to meet locally defined advisory criteria for 1 to 2 days (daytime highs=100-105° Fahrenheit).

What you should do if the weather is extremely hot:

  • Listen to NOAA Weather Radio for critical updates from the National Weather Service (NWS).
  • Never leave children or pets alone in closed vehicles.
  • Stay indoors as much as possible and limit exposure to the sun.
  • Stay on the lowest floor out of the sunshine if air conditioning is not available.
  • Postpone outdoor games and activities.
  • Consider spending the warmest part of the day in public buildings such as libraries, schools, movie theaters, shopping malls, and other community facilities. Circulating air can cool the body by increasing the perspiration rate of evaporation.
  • Eat well-balanced, light, and regular meals. Avoid using salt tablets unless directed to do so by a physician.
  • Drink plenty of water; even if you do not feel thirsty. Avoid drinks with caffeine. Persons who have epilepsy or heart, kidney, or liver disease; are on fluid-restricted diets; or have a problem with fluid retention should consult a doctor before increasing liquid intake.
  • Limit intake of alcoholic beverages.
  • Dress in loose-fitting, lightweight, and light-colored clothes that cover as much skin as possible. Avoid dark colors because they absorb the sun’s rays.
  • Protect face and head by wearing a wide-brimmed hat.
  • Avoid strenuous work during the warmest part of the day. Use a buddy system when working in extreme heat, and take frequent breaks.
  • Check on family, friends, and neighbors who do not have air conditioning and who spend much of their time alone.
  • Avoid extreme temperature changes.
  • Check on your animals frequently to ensure that they are not suffering from the heat. Go to a designated public shelter if your home loses power during periods of extreme heat. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example: shelter 12345).



If you require more information about any of these topics, the following resources may be helpful.


Find additional information on how to plan and prepare for extreme heat and learn about available resources by visiting the following websites:


Learn about the emergency plans that have been established in your area by your state and local government. In any emergency, always listen to the instructions given by local emergency management officials.

Last updated: 08/31/2012 - 09:25 AM