Thursday, September 17, 2015

#NatlPrep : Tsunami Awareness


Credit NOAA



Note: This is day 17  of National Preparedness Month . Follow this year’s campaign on Twitter by searching for the #NatlPrep hash tag.

This month, as part of NPM15, I’ll be rerunning some edited and updated older preparedness essays, along with some new ones.


# 10,531


The full extent of the damage from last night’s Chilean 8.3 Quake & Pacific Tsunami Watch has yet to be revealed, but the good news is this quake struck some distance from the highly populated capital of Santiago. Coastal regions near the epicenter have reported tsunami waves as high as 15ft.

While a major tsunami is not expected when the effects reach the Hawaiin islands later this morning (3 am local time), strong currents or small waves dangerous to persons or crafts in or very near the water are possible. There is also an advisory issued for a small section of the California coast.


Although extensive damage beyond Chile is unlikely with this tsunami, it does serve as a warning that all coastal regions of the United States are vulnerable to tsunamis, and that some in the past have been quite destructive.


Primarily thought of as a West Coast, or Pacific Ocean hazard, Tsunamis have also swept across the Atlantic and Caribbean basin as well, something we looked at last spring in The Caribbean’s Hidden Tsunami Potential (Revisited).


In 2013 the USGS released a report detailing the likely West Coast impact of a tsunami generated by a 9.1 Alaskan earthquake – and the numbers are sobering.  From the USGS news release  Experts Team Up on Tsunami Resilience in California:


In this scenario approximately 750,000 people would need to be evacuated, with 90,000 of those being tourists and visitors. Additionally, one-third of the boats in California's marinas could be damaged or completely sunk, resulting in $700 million in losses. It was concluded that neither of California's nuclear power plants would likely be damaged by this particular event.


The study (link) also estimates damage to marinas, businesses and homes range between $3.5 billion and $6 billion, and as many as 8,500 could be left homeless.


An even greater threat lurks along the Cascadia Fault line, which runs parallel to the Pacific Northwest Coastline and has a long history of a producing major earthquakes and tsunamis, the last one in the year 1700. The geological record indicates massive quakes have struck the region at least 7 times over the past 3500 years.


Recent publicity in the New Yorker Magazine has raised awareness of this threat and we’ve seen renewed calls for preparedness in the region (see OSU: Pragmatic Action - Not Fatalism - In Order To Survive The `Big One’).   We looked at the threats posed by this particular fault line back in 2011 in Just A Matter Of Time.


While strong earthquakes are the most common cause of tsunami waves, other causes include submarine landslides, meteo-tsunamis generated by anomalous weather events, and rarest of all – tsunamis caused by asteroid impacts.


The mysterious Daytona Beach `rogue wave’ of 1992 -  which 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,  was theorized to have been a meteo-tsunami.


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.


Before 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.


You’ll find more Tsunami preparedness information on the NOAA TsunamiReady Website:



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.


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.


For more on  disaster preparedness, I would invite you to visit, FEMA,  or revisit these blogs:

In An Emergency, Who Has Your Back?

An Appropriate Level Of Preparedness

When 72 Hours Isn’t Enough.


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