guiding sign for fleeing residents

Source: Pacifc Tsunami Warning Center

Pacific Ocean Warnings
Mikel Szyman 
Part of Waves of Devastation, a class website on the Indian Ocean Tsunami & Global Environmental Injustice, produced by students of Geography 378 (International Environmental Problems & Policy) at the University of Wisconsin-Eau Claire, USA, Spring 2005.


"There is a legend in Japan of a man who saved a village from a tsunami's wrath. The man lived on the mountainside above the town. One day he looked down the mountain, and then, to his family's dismay, lit his ricefields on fire. His family tried to convince him to put the flames out and he said "Do not put these fires out." Some villagers below noticed the flames,and when they were not put out they ran up the mountain side to help.When they arrived they were confused to see the old man and his family doing nothing to stop the flames. More shock followed when he told them "Do not put these fires out." Even more villagers came yet to help when they saw the fires continue to burn. Each time a new group of people showed up, they would receive the same response.

Soon, the entire village was on the mountainside trying to convince the old man to put the fires out. All of a sudden, they all turned and looked down below. They watched in silence as their town was torn to pieces by a raging wall of water. At first they were struck with shock and sadness. Then they realized not a single one of their neighbors had been lost in the devastation thanks to the old man's foresight."

Unfortunately, there is not a similar old man on all the edges of the Pacific Ocean to save his neighbors from incoming killer waves. The countries of the Pacific Ocean rim, however, have come up with warning systems to give their citizens enough time to reach safety in the event of a tsunami. This page will examine the main system of warning for those countries which border the Pacific Ocean. This page will also show some examples of what different countries ask of their citizens in a tsunami.


The Main Warning System

The central warning system for the Pacific Ocean is controlled out of two centers. One is found on Ewa Beach, Hawaii, which looks out for the lower, southern portion of the Pacific. The other is in Palmer, Alaska, which keeps an eye on the northern regions. The two of these centers together serve 26 member states and are run by the U.S. National Oceanic and Atmospheric Administration's (NOAA) National Weather Service.

The PTWC's mission is "detect, locate, and determine the magnitude of potentially tsunamigenic earthquakes occurring in the Pacific Basin or its immediate margins" (Tsunami Warning System) . This is done in conjunction with international geological groups along with the National Earthquake Information Center. When seismic conditions could possibly enerate tsunami activity, the PTWC can predict where the wave is headed, how tall and fast it is, and when it will reach determined populations. With these types of predictions, scientists are able to warn endangered communities ahead of time.

Sometimes a tsunami is detected that is large enough to alert every part of the Pacific Ocean Basin. It is definitely in everyone's best interest to heed these and any tsunami warnings if they are ever heard.

The instruments and processes used to detect seismic and tsunami activity in the Pacific region are so sophisticated they detected the 2004 Indian Ocean Tsunami before it hit land. (There is more information about that on the page "Indian Ocean Warnings" )

How the System Works

Protecting the West Coast of North America, an array of six buoys are
deployed in Pacific waters.  Completed in 2001, the Deep Ocean
Assessment and Reporting of Tsunamis (DART) Project is the system which would sound the clarion which might potentially save millions of inhabitants, were a tsunami to occur in the Pacific Ocean.  Each buoy is anchored to the Ocean floor in deep water and consists of sensors and antennae which provide, via satellite, real-time data in two modes of oceanic and atmospheric conditions.  These are standard and event modes.  In standard mode, average sea surface height is routinely reported every 15 minutes, 24 hours a day.  If on-board software detects an event, the system goes into event mode, in which “15-second values are transmitted during the initial few minutes, followed by 1-minute averages. The system returns to standard transmission after 4 hours of 1-minute real-time transmissions if no further events are detected.”  (DART)

The cost per unit for these buoys is around a quarter-million dollars, with much higher costs coming into play when one considers deployment, maintenance, and system operation.  However, the benefit of a successful warning given in the event of a threat could far outweigh any of these expenditures. Since the tragic events of December 26th, 2004, the United States congress has been evaluating a plan which would increase by 32 the number of DART buoys deployed.

Tsunami Etiquette:

How to Behave During a Tsunami Warning

Here in the Midwest, we grew up with tornado drills. The local sirens would blare, and we would all climb under our desks or go to the basement. For people living on the banks of the Pacific Ocean, tsunami drills may not be out of the question. Here are what some governments suggest to their citizens:

In the United States. people are told to become familiar with and follow signs like this one in the event of a Tsunami warning:

Below is an educational poster from the Philippines. Click on it to see a large, readable, learnable version:

Source: Philippine Institute of Volconology and Seismology

In Japan, the system is so sensitive that citizens will know within 3 minutes of tsunami detection that a wave is headed their way. Alerts go out over TV and radio. The beachfront has loudspeakers like that pictured below to get people moving to higher ground as quickly as possible.

Source: Science Museum UK


What Will Keep You Safe

Tsunamis in the Pacific regions would never get away being undetected. Once waves are detected, people on land are warned. Residents are offered the following advice:
1) Stay well informed on what to do before a tsunami hits, make sure you and
your family knows what to do.
2) Take all warnings seriously! This includes sirens, broadcasts, and phenomena such as an unusually quick drop in the ocean levels around you.
3) Head for higher ground immediately. The higher the better. Tell everyone you see to follow you.
4) Do not come down until it has been announced that the danger is over..
The scientists keeping an eye on the Pacific Ocean know exactly what they
are doing, and that is keeping a lot of people out of harm's way. Inhabitants of these regions need to make sure they understand and trust the Pacific Tsunami Warning System. Unfortunately, the same cannot be said for those living in the Indian Ocean region. Because these countries are are not as financially or technologically well-off as nations bordering the Pacific Ocean, the world witnessed exactly what happens when disaster warning systems are not put in place before tragedy strikes. All that can be done now to prevent such devastation in the future is to make sure an Indian Ocean tsunami warning system is put in place. This is something to which the rest of the world, especially the wealthiest nations, needs to contribute time, technology, and money so that this historic tsunami disaster is never repeated.


For more information on this topic:

NOAA's NWS Pacific Tsunami Warning System:


Philippine Institute of Volconology and Seismology:

The Tsunami Warning System:

And thank you to my big brother who first told me the story of the heroic rice farmer!