On average, two tsunamis occur per yearthroughout the world which inflict damagenear the source. Approximately every 15 yearsa destructive, ocean-wide tsunami occurs suchas the December 2004 Sumatra event.

Tsunami velocity depends on the depth ofwater through which it travels. Tsunamistravel approximately 475 mph in 15,000 feetof water. In 100 feet of water the velocitydrops to about 40 mph.

The currents associated with tsunami wavesare much stronger than those experiencedfrom a typical coastal flood event. Fatalitiesand injuries in tsunamis are usually the resultof both drowning and debris impact.

Tsunamis range in size from a few inches toover one hundred feet. In deep water(greater than 600 feet), tsunamis rarely exceedthree feet and often aren’t even be noticed byships at sea.

As with any potential disaster, develop a familydisaster plan.

Be prepared to survive on your own for aminimum of three days because power andinfrastructure could be significantly damaged.

Prepare a disaster supply kit for your home,automobile and work.

Take a first aid course and learn survival skills.Knowledge is your greatest defense againstany potential disaster.

TsunamiReady is a National Weather Service (NWS)initiative that promotes tsunami hazard awareness and preparedness in communities where tsunamis pose athreat to life and property. Recognizing the relativelyinfrequent nature of such events, the TsunamiReadyprogram encourages collaboration among federal, stateand local emergency management agencies, the public, andthe NWS tsunami warning system so that no one iscaught off guard next time such an event occurs.

New Jersey Office of Emergency Managementwww.state.nj.us/njeom

Delaware Emergency Management Agencywww.state.de.us/dema/default.shtml

NOAA/National Weather ServicePhiladelphia/Mt. Holly

www.weather.gov/phiwww.weather.gov/phi/reports/tsunami.htm

NOAA Tsunami Programwww.tsunami.noaa.gov

National Tsunami Hazard Mitigation Programwww.pmel.noaa.gov/tsunamihazard/links.htm

International Tsunami Information Centerwww.prh.noaa.gov/itic

United States Geological Surveywww.usgs.gov

Federal Emergency Management Agencywww.fema.gov

National Sea Grant Programwww.nsgo.seagrant.org

Stevens Institute of Technologywww.stevens-tech.edu

This publication was supported by the National Sea Grant College Program of the U.S. Department ofCommerce’s National Oceanic and Atmospheric Administration under NOAA Grant #NA060AR4170086. Theviews expressed herein do not necessarily reflect the views of any of those organizations. NJSG-06-650

- Photos Courtesy NOAA

A tsunami is a series of ocean waves caused by anylarge, abrupt vertical displacement of the seafloor. If the displacement is close to the coastline,local tsunamis can demolish coastal communitieswithin minutes. A very large displacement can causelocal devastation AND export tsunami destructionthousands of miles away (a tele-tsunami).

Tsunami is a Japanese word consisting of twocharacters: “tsu”, meaning harbor, and “nami”,meaning wave.

Tsunamis rank high on the scale of natural disasters.Since 1850, tsunamis alone have been responsiblefor the loss of over 420,000 lives and billions ofdollars of damage to coastal structures and habitats.

There are many causes of tsunamis, including earth-quakes, landslides, volcanic eruptions, explosions, andmeteorite impacts -- any disturbance that displaces alarge water mass can generate a tsunami. Tsunamisin the Atlantic Basin are most commonly generatedby earthquakes and landslides. Primary sources oftsunami-producing earthquakes in the Atlantic Basinare located near Puerto Rico, Portugal, and theCanary Islands. Underwater landslides associatedwith smaller earthquakes and volcanic eruptions arealso capable of generating tsunamis.

Think vertical! If possible, go to an area 50 feet abovesea level. Since high ground is not common to the NewJersey and Delaware coastline, find a strong multi-storystructure and go to the highest level.

Remember, earthquakes and underwater landslidescause tsunamis.You may not feel an earthquake orlandslide.A rapid recession of the ocean beyond thenormal low tide level typically precedes a tsunami. Ifyou feel an earthquake or see the ocean recede,quickly seek higher ground.

If an earthquake occurs near the coast, drop, get undera sturdy object, and hold on. Since tsunamis can occurquickly after an earthquake, finding a structurally soundelevated building is imperative.Tsunamis typically arriveat the coast as a series of waves. Since waves mayarrive for hours after the causative event, stay elevated.Do not return to ground level after the first wave hasreceded; more may be on the way.

Listen to NOAA Weather Radio All Hazards or your favorite media source for the official government-issued “All Clear”.

What is a Tsunami?

Where Do I Evacuate?

Tsunami Generation

Where Do Tsunamis Occur?

Atlantic Basin Tsunamis

Predicting when and where the next tsunami will strikeis currently impossible. However once generated,forecasting tsunami arrival and impact is possible withseven new NOAA Deep Ocean Assessment andReporting of Tsunami (DART) buoys in the AtlanticBasin, as well as a fully staffed Tsunami Warning Center.

Tsunamis can occur at anytime of day or night,under any and all weather conditions, and in allseasons. Beaches open to the ocean and bayentrances or tidal flats, and the shores of coastalrivers are especially vulnerable to tsunamis.

Recent research has indicated that the U.S. eastcoast and the Caribbean could be impacted by atsunami generated by an eruption and collapse ofthe Cumbre Vieja Volcano, located in the CanaryIslands. Studies suggest that during a futureeruption, the Cumber Vieja Volcano mayexperience a catastrophic flank collapse,resulting in a landslide-generated tsunami thatcould impact the east coast of the United States.

Tsunamis in the Atlantic Ocean may also becaused by underwater landslides near thecontinental shelf, and scientists are working onprojects to predict how large a wave this wouldgenerate. By studying the nature and weight ofsediments accumulated on the upper slope of thecontinental shelf, along with sedimentcohesiveness and slope angle, research scientistscan determine the probability of a landslide.

Historic records demonstrate that earthquake-generated tsunamis have already impacted theU.S. east coast. In 1929, an earthquake off theGrand Banks produced a tsunami that causeddeath and destruction, mostly in Newfoundland.East coast tide gauges can detect even smalltsunami waves caused by distant earthquakes. Forexample, in 1918 and 1946 gauges recordedwaves just a few inches high generated byearthquakes in Puerto Rico and the DominicanRepublic, respectively. More recently,Atlanticbasin gauges recorded 5-10 inch waves generatedby the December 2004 Indian Ocean tsunami.