The National Oceanic and Atmospheric Administration (NOAA) has announced that the final two buoys are up and running in an unprecedented 39-buoy tsunami warning system designed to protect U.S. coastal communities from a similar fate as the deadly Indian Ocean tsunami.
According to a report in Discovery News, the buoy array is a dramatic improvement over the six-buoy system that existed before the 2004 disaster, which killed upwards of 350,000 people.
AdvertisementThe Deep-Ocean Assessment and Reporting of Tsunami (DART) buoy system, plus seismometers and other instruments, collect and transmit tsunami vital signs in hazardous earthquake zones all around the Pacific Ocean, as well as in the North Atlantic, Caribbean and Gulf of Mexico.
The system is designed to incorporate what is known and accommodates what remains unknown about the planet's most powerful earthquakes and waves.
The Indian Ocean tsunami didn't just provide the impetus to check-cutters inside the Beltway. It also offered valuable scientific lessons used in developing the DART system.
A rupture in a subduction zone, a place where one plate of the Earth's crust is being shoved underneath another, created the Indian Ocean tsunami's driving force, the Great Sumatra-Andaman Earthquake.
"The rupture, 800 miles (1,300 km) long, moved a block of earth as long as California about 30 feet," explained geophysicist Seth Stein of Northwestern University.
The tsunami created by the rare "mega-thrust" earthquake was of similarly impressive breadth.
"In order not to miss broad wave fronts of future tsunamis, the DART buoys in the Pacific Ocean were placed 400 to 600 miles (700 to 1,000 km) apart," said Eddie Bernard, director of NOAA's Pacific Marine Environmental Laboratory in Seattle.
The 200,000 dollars DART buoys are only half of the picture.
The other half of the system sits on the ocean floor, sometimes thousands of feet down. This sea floor unit measures changes in water pressure, which can be converted into water depth, and transmits the data via an acoustical modem to the buoy on the ocean surface.
Each buoy uses satellites to relay up to 15 minutes of data to two NOAA tsunami warning centers in Hawaii and Alaska, which operate 24 hours a day, seven days a week.
At the warning centers, the data is fed into 26 new tsunami generation models. If buoys near the epicenter detect a large tsunami, and the models forecast it coming ashore, forecasters can broadcast specifics about where, when and how large the tsunami will be when it hits.
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