Posted in BE SAFE, Disaster Preparedness, Earthquakes, Emergency Evacuations, Health & Welfare, Hurricanes, Tsunamis, Uncategorized

The Tsunami Threat

Cartoon drawing of a tsunami with sun in background
Are you prepared for the threat of a tsunami?

Another serious topic! Don’t fret. I’ll still throw in my legendary wit and wisdom. Although rare, tsunamis pose extreme danger in coastal areas due to their sheer size and difficult predictability. In the United States, tsunamis are a threat that could one day cause a major disaster. According to the California Seismic Safety Commission, 80 tsunamis have been recorded over the past 150 years in California. In 1964, the Great Alaskan Earthquake produced numerous tsunamis, including some that killed twelve people in California and four in Oregon.

Although they are often referred to as “tidal waves,” tsunamis are not generated or affected by tidal forces. In fact, tsunamis can do considerable damage even if they occur during low tides.

How Tsunamis are formed:

  • They are categorically caused by giant furry Newfoundlands running into lakes and oceans, causing massive wave vibration things. Right?
  • Actually, tsunamis result from the displacement of a large volume of water, which is similar to what happens to my water bowl when a toddler walks into it. How does he feel when I try to eat his grilled cheese?
  • Earthquakes, volcanic eruptions and landslides can lead to tsunamis.
  • When an earthquake occurs in the ocean, two plates are slipping, which causes a release of energy. (Speaking of plates slipping. I’ve been waiting for a whole plate of dry rubs ribs to slip or tilt when they’re en route to the grill. If they fall, they’re mine!) In the water, this movement of plates is transferred into wave- energy.
  • Although the waves generated at first have a very small height, they are very long (and are referred to as wavelengths). In the open ocean, tsunamis often pass by unnoticed by ships.
  • Reaching speeds of up to 500 mph, the waves slow and increase in height as they reach shore. I swear I reached 501 mph once when I was chasing Whiskers. I almost got him.
  • “Mega-Tsunamis,” with waves hundreds of feet high, can be caused by massive landslides.

Detection Systems:

After the Indian Ocean tsunami in 2004, the Bush Administration enacted more tsunami planning and early-warning systems for the United States. Part of this effort included an increase in the number of Deep-Ocean Assessment and Reporting of Tsunami (DART) program buoys. Each of these buoys is anchored to the sea floor and relays valuable information including pressure and temperature data which are used to calculate wave height. GPS-based information is relayed back to a satellite and picked up by the receiving station. Don’t ask me how it works. It just does!

very simple line drawing of a wave
Refer to NOAA for weather-related warnings.

Implications for Building Owners and Property Managers:

  • Review tsunami inundation zone maps that are offered by Federal agencies. These maps are similar to flood plain maps and provide a clear picture of potential threats. In California, the State Office of Emergency Services produces these maps, which are increasingly used by municipalities for evacuation planning.
  • Read California’s Seismic Safety Commission tips on earthquakes and the related tsunami threat.
  • Be aware of warnings issued by the National Oceanic and Atmospheric Administration (NOAA). In June of 2005, a watch was quickly issued for the Washington and California coasts.
  • Consider your building’s structure to determine if it can sustain tsunami forces, which differ greatly from that of earthquakes.

We all know that knowledge and preparedness saves lives. Although tsunamis that cause extreme damage are rare, they are potentially devastating and occur with minimal warning. For coastal properties, implementing tsunami-specific information into disaster planning helps building owners and facility managers cover all the bases and remain prepared for any threat. Don’t rely on “it hasn’t happened yet” thinking. Plan for the unexpected!

When a disaster strikes, prior planning and clear decisive action can help save lives.  For the latest emergency management training for facility/building managers, contact RJWestmore, Inc. Our new Version 2.0 e-based training system offers the best emergency training system with automated and integrated features. Visit for more information and remember to BE SAFE.