Tuesday, July 24, 2012

East Coast Tsunami Threats


# 6448


East Coast tsunamis, while admittedly rare – do occur - and history has shown that they can be extremely destructive.  Last March in Tsunami Awareness Week: March 20th – 26th I wrote about a list of known or suspected Atlantic and East Coast Tsunamis 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


  • 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



While little remembered today, in November of 1929 a destructive North Atlantic tsunami came ashore after a 7.2 magnitude earthquake struck offshore from Newfoundland.  Three hours later a 3 to 4 meter tsunami washed across many coastal fishing villages on the Burin Peninsula, killing 28 people and leaving as many as 10,000 homeless.


In the spring of 2011 we took  A Look At Europe’s Seismic Risks, which gave details on the mother-of-all Altantic basin tsunamis, which was generated by the Lisbon Earthquake  of 1755 (Est. 8.5 magnitude).


Tremendous tsunamis (20+ meters) were reported in Northern Africa, Spain and Portugal, and smaller waves washed ashore in the Caribbean and the Atlantic Coast of the New World many hours later. 



Tsunami Travel Times from the 1755 Quake – Credit Wikipedia


Although accurate numbers are impossible to come by, in Lisbon alone the death toll is estimated at between 10,000 and 100,000.  Most historians place the number at the high end of that range.


While far less common that their Pacific counterparts, east coast tsunamis - by reason of geography, population density, and a general lack of public awareness - have the potential to be extremely dangerous.


Courtesy of a tweet from FEMA Director Craig Fugate yesterday, I found this fascinating slideshow training presentation on the East Coast Tsunami Threat that expands considerably on my earlier blog post.


One of the most remarkable slides in this 29 minute presentation shows that while they happen less often than Pacific tsunamis, historically the east coast death toll is almost as great as those from the west coast.




Depending upon the type of precipitating event (seismic activty, landslide, asteroid/meteor impact, etc) and the location, tsunami travel and warning times around the Atlantic will vary from minutes to many hours.






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.


While it may seem unlikely that a tsunami will affect you or your region - this is just one of many potential hazards that may threaten you and your community - and they all require similar preparedness steps.


Knowing your local threats, whether they be tsunamis, forest fires, floods, earthquakes or hurricanes  . . . and then becoming prepared to deal with them, will provide you and your family the best safety insurance available.


To become better prepared, visit the Ready.gov site today.


Credit Ready.gov


To learn how to prepare as an individual, family, business owner, or community I would invite you to visit the following sites and use THIS LINK to access some of my preparedness blogs.


FEMA http://www.fema.gov/index.shtm

READY.GOV http://www.ready.gov/

AMERICAN RED CROSS http://www.redcross.org/

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