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February 2005                                                                            Volume 8 - Number 1

Tsunami Disaster Updates...

Oregon Tsunami Warning System

By Erika Kuhn

In the event of a tsunami, there has historically been little policy established to warn the public of such an event. The National Tsunami Hazard Mitigation Program was established in the United States to provide the public warning, mitigation, and hazard assessment.

Two tsunami warning centers have been established by the National Oceanic and Atmospheric Administration (NOAA): the West Coast/Alaska Tsunami Warning Center (WC/ATWC) and the Pacific Tsunami Warning Center (PTWC). The centers are responsible for deploying Deep-ocean Assessment and Reporting of Tsunami (DART) buoys within the Pacific Ocean to provide warning for potential tsunamis. They are currently looking to deploy 32 more DART buoys for a fully functional warning system.

Tsunamis are typically detected initially by seismic data. Once detected, the tsunami warning centers are responsible for issuing alerts to state emergency officials via bulletins (distributed via several communication methods). Bulletins sent to state emergency officials are assigned a criticality definition, as listed below:

Ø Warning – indicates a tsunami is imminent within the warned area of responsibility, and coastal areas should prepare for flooding;

Ø Watch – alert to areas outside of the direct warned area of responsibility. May be upgraded to a warning or canceled, depending on the strength of the tsunami;

Ø Advisory – indicates a major earthquake has occurred, which may potentially lead to a tsunami warning. Or, a tsunami has been identified but the event does not pose a threat to the specified area;

Ø Information Bulletin – indicates an earthquake occurred; however, the event was most likely not destructive enough to cause a tsunami; or

Ø Information Message – indicates that an earthquake below M6.5 occurred. The message is solely to inform residents that there is no tsunami danger.

The Oregon state emergency management agencies receive the broadcast bulletin from the NOAA, and re-broadcast the message over state-owned systems (e.g. Law Enforcement Data System (LEDS), radio, telephone, etc) to the local jurisdictions within about 3-4 minutes. Since 1980, the average time it has taken to issue a tsunami warning via the warning centers has been 11 minutes (warnings have been issued more quickly over time as technology improves).

The general public can also receive audible warning messages from the NOAA Emergency Alert System (EAS) that are broadcasted along the west coast via radio and television. Oregon communication systems (radio, TV, etc) with at least 10,000 subscribers are required by the FCC to have EAS equipment installed and functional.

Evacuation procedures are the responsibility of the local officials, and are not broadcast via these communication mechanisms.

Although the Oregon/west coast tsunami warning systems have been established, there are limited program dollars dedicated to improving the cause. The current budget is being used to create tsunami inundation maps, evacuation maps, and to provide education. The Bush administration is currently working to improve tsunami detection and warning capabilities, and commit to spending an estimated $37.5 million over the next two years.

Source:

http://www.wsspc.org/tsunami/OR/Tsuanami_Procedures_Oregon-2001.pdf

http://www.allamericanpatriots.com/m-news+article+storyid-4510.html

http://dssresources.com/news/531.php