By Cheryl Pellerin
Washington File Staff Writer

Washington – The first regionwide test of the Tsunami Warning System in the Pacific, called Exercise Pacific Wave ’06, will be carried out May 16 and 17.

The exercise, sponsored by UNESCO’s Intergovernmental Oceanographic Commission (IOC), it intended to increase preparedness, evaluate response capabilities in each of 28 countries and improve coordination throughout the region.

The IOC established the Tsunami Warning System more than 40 years ago to monitor seismological and tidal stations throughout the Pacific Basin, evaluate potentially tsunami-generating earthquakes and disseminate tsunami warning information.

The U.S. National Oceanic and Atmospheric Administration’s (NOAA) Pacific Tsunami Warning Center (PTWC) in Ewa Beach, Hawaii, is the operational center of the IOC Tsunami Warning System. (See related articles.)

“To be effective, warning systems must maintain a high level of readiness,” said UNESCO/IOC Executive Secretary Patricio Bernal.

“This means emergency agencies should regularly practice their response procedures,” he added, “to ensure that vital communications links work seamlessly and that agencies and response personnel know the roles that they will need to play during an actual event.”

Coordinating the exercise is a task team chaired by Australia that includes representatives from NOAA’s PTWC and West Coast/Alaska Tsunami Warning Center, the IOC Northwest Pacific Tsunami Advisory Center and the International Tsunami Information Center. Country representatives from Australia, Chile, France, Fiji, New Zealand, Nicaragua, the Russian Federation, Samoa and the United States are also on the task team.

TSUNAMI WARNING SIMULATION

The simulation will be carried out in two stages, beginning with a mock tsunami bulletin from the NOAA PTWC May 16.

The bulletin – clearly indicating that it is a test and not an actual warning – will be transmitted to designated contact points and national emergency authorities responsible for tsunami response in each country.

In the second stage, conducted that day or on the following day, government officials will disseminate the message in each country to local emergency management and response authorities, simulating what would happen in a real situation.

Notifying authorities of at least one coastal community is set as a sufficient measure for testing the end-to-end process of an entire country for the first exercise.

An end-to-end system is one whose disaster management technology is based on a global framework and links effectively through international, national and local networks to make sure that warnings are generated and that people along every threatened shore are notified and know how to avoid danger.

PERFORMANCE MEASURES

Exercise Pacific Wave ’06 will be the first drill in a series of regular exercises. Outcomes and performance measures of the test will include the following information:

• How each member state received the warning (Global Telecommunication System, fax, e-mail);

• Elapsed time between bulletin issuance, receipt and public notification;

• What assessment tools were used to decide about evacuations;

• How the public was notified and instructed;

• Feedback from affected and involved parties regarding their performance and the performance of information providers; and

• Media response.

The report will be presented during the next IOC Executive Council meeting in late June.

UNESCO Director-General Koïchiro Matsuura has urged all countries in the region to take part in the exercise.

“UNESCO is committed to helping countries to improve their warning capability,” Matsuura said.

“We are confident the results of this exercise will not only help to protect the public from future tsunamis,” he added, “but will also serve as a testing model for other areas that could be impacted by these destructive waves.”

A TSUNAMI DETECTION MODEL

The PTWC in Hawaii is part of the NOAA National Weather Service. Until a few years ago, the PTWC served the Pacific Basin as a regional and long-distance tsunami warning center and as a local tsunami warning center for Hawaii.

Today it serves as an interim warning center for the Indian Ocean – in cooperation with the Japan Meteorological Agency (JMA), which issues bulletins for hazard-related events in the Indian Ocean – and the Caribbean until systems are in place for those regions.

The PTWC and its operations, with 40 years of experience in detecting and providing warnings about tsunamis and other hazards, serve as a general model for the Indian Ocean tsunami warning system.

The center is mainly a communications hub that receives, integrates and analyzes data from seismic stations, which measure the Earth’s vibrations, and ocean sensors, which measure tide levels and water pressure.

Seismic data flow into center computers from 180 seismic stations worldwide. Some stations belong to the PTWC but most are from cooperative networks like the 130-station Global Seismographic Network operated by the U.S. Geological Survey and the National Science Foundation and other regional networks.

MONITORING DATA STREAMS

The PTWC computers monitor the data streams for an earthquake. If they find an earthquake has occurred, they determine an initial location and sometimes a magnitude. The staff collects and analyzes seismic data to detect and characterize earthquakes.

When the computers spot a large earthquake, staff members start monitoring sea-level data from near the earthquake epicenter to detect and measure potential tsunami waves.

Sea-level data come from tide gauges, which measure water levels near the shore, and deep-ocean tsunami detection instruments called DART (deep ocean assessment and reporting of tsunamis) buoys, developed by NOAA’s Pacific Marine Environmental Laboratory in Seattle. The gauges and buoys have radio transmitters to send their data through satellites to the Hawaii warning center in near real time.

Based on that information, staff members decide whether to initiate a tsunami warning.

Then, based on tsunami forecast modeling – computer-based inundation models that show how a tsunami might affect a specific coastal area – and on actual data from ocean sensors, they decide whether to continue the warning, cancel it or upgrade it.

Most importantly, the PTWC creates and disseminates information to those who need it.

Information about the Pacific Tsunami Warning Center is available at the NOAA Web site. Information about the U.S. government Indian Ocean Tsunami Warning System Program is available on a USAID Web site.