Tsunami Hazards in Southern California

So this event is from almost a year ago, just a few months after I graduated.  A graduate class on hazards and risk management gave a presentation on their research concerning disaster management of tsunamis.  They discussed the consequences of the 2004 tsunami disaster in the Indian Ocean and what could happen in Southern California if we do not adopt better management practices for safety and response.

The students started out with some tsunami characteristics.  They can travel long periods for long distances, about 800-900 km per hour.  They lose little energy and the energy and speed of the wave is what causes the damage.  The causes of can be from earthquakes and volcanic eruptions.  Ninety percent of these earthquakes have fault lines that slip upward.  Landslides also contribute to tsunamis and can occur below and above water.  They are focused in certain areas, such as the one that happened at Lituya Bay in Alaska.

Volcanoes can cause a multitude of events.  They can have pyroclastic flows, defined as fast moving rock and gas at speeds of up to 450 mph or 700km/hr.  They can also cause submarine explosions and earthquakes with eruptions, all capable of starting tsunamis.  While there is no historical evidence, meteorites and/or asteroids could be 10 times more powerful than the largest earthquake and thus create truly devastating tsunamis.

As for the risk for Southern California, a large tsunami would be a California emergency and in the case of Long Beach could mean a large part of the city would be underwater.  Part of the process of dealing with such events lies in preparedness and mitigation.  One aspect of that is the building safety code.

Long Beach, CA tsunami hazard zones.  Map from the California Dept. of Conservation.

Long Beach, CA tsunami hazard zones. Map from the California Dept. of Conservation.

A major player in this is the International Code Council (ICC), which is a consortium of professionals who publish codes and industry standards.  Such codes and standards though are not law until a government entity adopts them.  Building, fire and mechanical codes are revised every three years and are adopted by the state legislature.  These codes can be enforced by local governments as state law through the California Building Standards Commission.  They also produce amendments and interpretations of the codes/laws.

One question to ask when engaging in this kind of management is “Are all hazards accounted for?”.  Some issues to consider are seismic-sheer walls, the foundation, wind- convection design and loads and internal air quality, which relates to medical conditions such as mold production.

What about hazards after the impact of a tsunami?  In the case of the 2004 tsunami, 163,560 people were presumed missing/dead.  Mass death can lead to other concerns including PTSD and the potential for continued health concerns (Doocy et al 2007).  Kaye (2005) found that polluted water covered much of Asia after the tsunami, which poses significant health risks as these pools of water attract insects.  One way to combat the bugs is to spray pesticide on the pools.  This method was especially used in Thailand.  Another health risk is a unique form of pneumonia, which presents itself after a tsunami and is often attributed to the debris in the air.

Graph showing age-specific tsunami mortality rates.  Image from Doocy et al 2007.

Graph showing age-specific tsunami mortality rates. Image from Doocy et al 2007.

What the students aimed to stress was the current lack of code considerations for tsunamis and a need for progress toward advanced safety.  One group that could help with this is the American Society of Civil Engineers.  They have produced a new chapter called ASCE-7, which deals with loads for structures.  Coming back to the International building code, California has an optional tsunami section, which has not been adopted by any state agencies.  It references FEMA standard P646A, which discusses vertical evacuation structures that provide tsunami shelter and are still in recommendation section.

Fukushima’s tsunami disaster caught the world’s attention due to the lack of preparedness.  They then had to create standards from scratch and based them on the use of the structure.  The more important the structure, the more resistance required.

2011 Japan tsunami.  Image from abcnews.go.com

2011 Japan tsunami. Image from abcnews.go.com

Going back to California, Swift Trust/Mutual Acquaintanceship is another important aspect of disaster response.  Swift Trust is essential for groups that must work together hurriedly/temporary under time pressure and thus takes on heightened importance during disasters.  Mutual Acquaintanceship is when familiarization occurs at social occasions or in case of emergency organizations when they must work together to produce safety and response plans.

One example is the creation of early warning systems, increasing in the amount of danger:  green is an information statement, yellow means a watch, orange is advising and red a warning.  There are also local disseminations of alerts, such as sirens, reverse 911, emergency vehicles using loudhailers (public address systems), local Emergency Alert System (EAS) activation, Citizens Band (CB) radio and social media activation.

Volcano Alert Levels.  Image from www.caloes.ca.gov

Volcano Alert Levels. Image from http://www.caloes.ca.gov

At the Port of Los Angeles (POLA), there are 27 working terminals and 16 marines.  The Operational Guidance includes the EOC- Emergency Operations Center, DOC- Department Operations Center, MCC- Maritime Coordination Center, USCG – US Coast Guard, LAPP – LA Port Police, LAPD – LA Police Department, LASD – LA Sheriff’s Department and LAFD – LA Fire Department.

The POLA has an operations section, which responds to incidents and coordinates actions.  It also has a planning section, which identifies requirements and prepares plan permits as well as approval.  Two other sections include logistics and finance.  When it comes to disaster management, there are three types of classifications: incident, emergency and disaster.  A comprehensive evaluation should include mitigation, preparedness, response and recovery.  Two considerations are whether the environment is mature or not and what the critical infrastructure is.

As for tsunami mitigation, responders and planners need to assess the threats and vulnerability, consequences and overall risks.  Tsunami preparedness can include the BEEP Program (Business & Employer Emergency Preparedness), training modules, testing curriculum, tsunami signs, identifying evacuation routes, town hall meetings and demographics and education.

Tsunami  information for California.  Image from www.conservation.ca.gov

Tsunami information for California. Image from http://www.conservation.ca.gov

A last item mentioned was a Tsunameter, a type of tsunami pressure sensor, which can help in detecting tsunami waves as well as increasing the number of buoys in the ocean to collect data on ocean conditions.  This was done in the Indian Ocean, which went from six buoys to about 56.


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