Tsunamis are potentially devastating waves that can follow seismic events are threats to any coastal region. Florida has 1,197 miles of coastline, more than any of the lower 48 States. Since most tsunamis are associated with major earthquakes, the possibility of a tsunami impacting the Atlantic or Gulf Coasts of Florida is considered to be remote -- but it is not impossible. The Atlantic Ocean basin is not ringed by large faults as is the Pacific, which is associated both with earthquakes and tsunamis. It is thought that rare underwater landslides would pose a greater risk in the Atlantic Ocean. However, because of the horrific tsunami that impacted Southeast Asia in December 2004 and in recognition of the fact that a tsunami occurrence is possible, the Federal government has decided to expand its warning system to include the Atlantic and Gulf Coasts of the United States.

What could cause a Florida tsunami?

• Boundary between Caribbean, North American, and South American tectonic plates.
• Since 1848, eight tsunamis have originated here, causing over 2,500 deaths.

• 1918 tsunami from a magnitude 7.5 earthquake killed 116 in Puerto Rico.

Cumbre Vieja Volcano in the Canary Islands

• Potential for undersea landslide creating and Atlantic Ocean-wide tsunami (or tele-tsunami).
• Azores-Gibraltar Fracture Zone.
• Potential for earthquakes, causing Atlantic tele-tsunamis.

• 1755 earthquake devastated Lisbon, Portugal, and generated the only known Atlantic tele-tsunami.

Rogue Waves - not tsunamis, but still dangerous

• Little is known about this phenomenon, but likely cause is weather-related.
• 1992 rogue wave swamped 30 miles of shoreline around Daytona Beach, causing 75 injuries.

• 1995 rogue wave occurred from Tampa to Naples.

Tsunami Safety

• If you feel an earthquake or observe a sudden outgoing tide, evacuate the beach immediately, beyond the 300-foot danger zone (typically inland of coastal roadways).
• If evacuation of danger zone is not possible, move to the highest floor (at least 15 feet high) of a well-constructed building
• Never go to the beach to watch for a tsunami.
• WHEN YOU CAN SEE THE WAVE, YOU ARE TOO CLOSE TO ESCAPE.
• Tsunamis can move faster than a person can run!

U.S. Tsunami Product Definitions:

ADVISORY: A potential tsunami which may produce strong currents or waves exists. Significant widespread inundation is not expected.

WATCH: A potentially dangerous distant seismic event has occurred which may later impact the watch area with tsunami. Be ready to take action if a warning is issued.

WARNING: A potential tsunami with significant widespread inundation is imminent or expected. Widespread, dangerous coastal flooding accompanied by powerful currents is possible and may continue for several hours after the arrival of the initial wave.

INFORMATION STATEMENTS: An earthquake has occurred or 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 in your area.