31 March 2005

NOAA emphasizes need for global tsunami warning system

News of a major undersea earthquake in Indonesia resonated across the globe on Monday. Fortunately a destructive tsunami did not follow, unlike the previous strong earthquake that occurred only three months ago. Steps taken since the December 26 disaster allowed for a better exchange of information between NOAA and countries under the threat of a potential tsunami, but many hours of waiting for confirmation highlights the need for a more robust tsunami detection system.

The NOAA Pacific Tsunami Warning Center in Ewa Beach, Hawaii, received notification of the 8.7 quake in northern Sumatra eight minutes after it occurred, analyzed the data to determine location and magnitude, and issued a tsunami bulletin 11 minutes later. PTWC alerted the U.S. State Department, which then sent messages to the U.S. Embassy in Thailand, Myanmar, Jakarta, India, Bangladesh, Singapore, Malaysia, Sri Lanka, Maldives and Mauritius.

Also, within 35 minutes of the quake, the Pacific Region Headquarters of the NOAA National Weather Service notified the consulates of India and Indonesia who then informed emergency management in those and surrounding countries.

According to PTWC's initial bulletin, there was no tsunami warning or watch for the Pacific Basin and no tsunami threat to the Pacific coastlines, but given the severity of the quake there was the potential for a widely destructive tsunami to originate from the quake's epicenter. Those regions were warned of the possibility and urged to take immediate actions.

With buoys and tide gauges currently absent from the Indian Ocean, an actual tsunami could not be confirmed until observation reports were received from local authorities or until a tsunami reached an existing gauge, which took several hours.

Sea level readings from several of these gauges, far from the epicenter and received more than two hours after the earthquake, indicated a non-destructive tsunami was generated. A 10 cm wave was recorded at Cocos Island, followed by a 23 cm wave 20 minutes later.

"Here we go again. We knew quickly about the earthquake, its approximate magnitude and location, yet it took hours to determine if, in fact, it created a tsunami," said Brig. Gen. David L. Johnson, U.S. Air Force (Ret.), director of the NOAA National Weather Service. "The world needs more observing systems to issue timely, accurate and focused warnings."

"We believe that with a worldwide tsunami detection and warning system in place?one that includes Deep-ocean Assessment and Recording of Tsunami, or DART, buoys along major known subduction zones?the NOAA Pacific Tsunami Warning Center could have had a deep ocean measurement for this event in one hour, and based on that data, the warning message would probably had been canceled," Johnson said.

The United States, with NOAA as lead agency, is currently working with approximately 60 countries, the European Union and many non-governmental agencies in planning and implementing GEOSS, the Global Earth Observation System of Systems, that includes a global tsunami warning system.

"The Global Earth Observation System of Systems would certainly help us understand what is happening in our environment and assist in developing recommended actions to hazards like tsunamis in a more timely, accurate and focused manner," Johnson added.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation?s coastal and marine resources. NOAA is part of the U.S. Department of Commerce.

Relevant Web Sites
NOAA Pacific Tsunami Warning Center
Bulletins from the NOAA Pacific Tsunami Warning Center
NOAA Earth Observing System
NOAA Tsunamis Page
NOAA Tsunami Research

Media Contact:
Chris Vaccaro, NOAA National Weather Service, (301) 713-0622 ext. 134


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