Credit http://oceantoday.noaa.gov/tsunamiawareness/
# 8167
With two moderately strong earthquakes rocking the Caribbean in the past week, and dozens of smaller temblors, it’s probably a good time to talk about the small – but still very real– potential of seeing a destructive tsunami generated from a Caribbean earthquake.
Caribbean Quakes last 7 day – USGS
Last week’s 5.1 quake in Cuba was felt in Miami and Key West, and even as far north as Tampa, Florida (see Tampa Bay Times article Effects of moderate earthquake near Cuba felt in Tampa Bay area).
Admittedly, the Pacific and Indian Oceans are best known for these destructive tidal waves, with 2004’s Sumatran Earthquake / Tsunami and 2011’s Great Japan Earthquake / Tsunami together claiming more than 200,000 lives. But these are not the only oceans capable of generating destructive waves.
Last March, in Tsunami Preparedness Week, I presented a a list of known or suspected Atlantic & Caribbean Tsunamis, starting off with the Great Lisbon Earthquake of 1755 (see A Look At Europe’s Seismic Risks), which included:
- November 1, 1755 - Lisbon, Portugal
- October 11, 1918 - Puerto Rico
- November 18, 1929 - Newfoundland
- August 4, 1946 - Dominican Republic
- August 18, 1946 - Dominican Republic
- November 14, 1840 - Great Swell on the Delaware River
- November 17, 1872 - Maine
- January 9, 1926 - Maine
- May 19, 1964 - Northeast USA
POSSIBLE TSUNAMI
- June 9, 1913 - Longport, NJ
- August 6, 1923 - Rockaway Park, Queens, NY. An article on triplicate waves."
- August 8, 1924 - Coney Island, NY. Contains a discussion, “An Observed Tsunami Building In Coastal Waters?"
- August 19, 1931 - Atlantic City, NJ
- September 21, 1938 - Hurricane, NJ coast.
- July 3-4, 1992 - Daytona Beach, FL
The last suspected entry – the infamous Daytona Beach `rogue wave’ of 1992 - was described by witnesses as being between 10 and 18 feet tall, slammed onto a 27 mile stretch of Florida Beaches without warning and smashed hundreds of cars, causing as many as 75 (mostly minor) injuries.
Twice in 1946, Caribbean earthquakes generated (minimal) tsunamis recorded along the Eastern Seaboard as far north as Atlantic City, NJ although they did considerable damage, and claimed lives, closer to the epicenter.
In A Brief History of Tsunamis in the Caribbean Sea (2002), researchers James F. Lander, Lowell S. Whiteside, and Patricia A. Lockridge of NOAA’s National Geophysical Data Center list descriptions of of 91 reported waves over the past 500 years that might have been tsunamis within the Caribbean region.
Of these, the authors judged 27 to be actual tsunamis, while nine more were considered `likely’ tsunamis’.
In 2005, The Woods Hole Oceanographic Institution warned:
Major Caribbean Earthquakes and Tsunamis a Real Risk
Events rare, but scientists call for public awareness, warning system
January 13, 2005
Shelley Dawicki
A dozen major earthquakes of magnitude 7.0 or greater have occurred in the Caribbean near Puerto Rico, the U.S. Virgin Islands and the island of Hispaniola, shared by Haiti and the Dominican Republic, in the past 500 years, and several have generated tsunamis. The most recent major earthquake, a magnitude 8.1 in 1946, resulted in a tsunami that killed a reported 1,600 people.
With nearly twenty million people now living in this tourist region and a major earthquake occurring on average every 50 years, scientists say it is not a question of if it will happen but when. They are calling for the establishment of tsunami early warning systems in the Caribbean Sea, Gulf of Mexico and Atlantic Ocean, and better public education about the real tsunami threats in these regions.
And just last month the USGS warned of the threat in the following press release:
Earthquake/Tsunami Hazard in Caribbean Higher Than Previously Thought
Released: 12/20/2013 6:18:08 PMContact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communications and Publishing
Enough strain may be currently stored in an earthquake zone near the island of Guadeloupe to cause a magnitude 8 or larger earthquake and subsequent tsunami in the Caribbean, according to a new U.S. Geological Survey study.
USGS and French researchers studying the plate boundary in the Lesser Antilles region—the area where 20 of the 26 Caribbean islands are located—estimate that enough unreleased strain may have accumulated offshore of Guadeloupe to potentially create a magnitude 8.0-8.4 earthquake. A magnitude 7.5-8.5 quake in 1843 killed several thousand people in Guadeloupe, and a similar quake in the future could cause several tens to several hundreds of fatalities, and hundreds of millions to billions of U.S. dollars in damages. The paper was recently published in the Geophysical Journal International.
"Perception that a mega quake can occur in the Caribbean is low because none have been observed over the past century, and the rate at which the tectonic plates converge is fairly slow," said USGS scientist Gavin Hayes, lead author of the paper. "Nevertheless, we show that enough unreleased strain may have accumulated on the subduction zone since the 19th century to generate a mega quake in the future."
From NOAA, we’ve a short (3 minute) video on Tsunamis that helps explain the threat. Click through to watch on their website:
You can access current Tsunami warnings and arrival times at the Pacific Tsunami Warning Center.
As far as what to do before a tsunami threatens, READY.GOV has a Tsunami Awareness Page with helpful hints.NOAA provides several useful documents, including a Tsunami Zone PDF (see below) and Tsunami Web page.
Tsunamis, while comparatively rare, are just one of scores of possible disaster scenarios that one can find themselves suddenly thrust into.
When you add in the risks from earthquakes, hurricanes, tornadoes, floods, blizzards, and other – even more common – emergencies, it makes sense to maintain a general level of preparedness against `all threats’.
Everyone needs an appropriate disaster plan, just as everyone should have a good first aid kit, a `bug-out bag’, and sufficient emergency supplies to last a bare minimum of 72 hours.
As the graphic above from NOAA advises, people should consider maintaining a 2-week supply of supplies in their home. A topic I address in When 72 Hours Isn’t Enough.
As we move into the spring severe storm season, and ultimately back into the Atlantic Hurricane season, now is a good time to review and refresh your emergency preparedness plans.
For more on disaster preparedness, I would invite you to visit Ready.gov, FEMA, or revisit these blogs:
In An Emergency, Who Has Your Back?
