Maintenance of U.S. Tsunami Detection Buoys Difficult and Costly, GAO Reports
The National Oceanic and Atmospheric Administration (NOAA) is having a hard-time maintaining its network of expensive high-tech tsunami detection buoys, according to a Government Accountability Office (GAO) report released Wednesday.
The National Oceanic and Atmospheric Administration (NOAA) is having a hard-time maintaining its network of expensive high-tech tsunami detection buoys, according to a Government Accountability Office (GAO) report released Wednesday (.pdf).
Known as the Deep-ocean Assessment and Reporting of Tsunamis (DART) program , this network of 39 buoys makes up the early-warning system to protect 767 U.S. communities at risk of tsunamis—large, devastating waves, typically generated by seismic events or undersea landslides—that can destroy coastal and island communities.
(For more on the DART program's roll out, read "Tsunami Warning ," by former editor Robert Elliot in the Sept. 2007 issue of Security Management.)
The last significant tsunami hit U.S. soil in September 2009, when a series of waves hit American Somoa, killing 190 people and wiping out coastal infrastructure. In February, NOAA scientists initially feared Hawaii could get pounded by a massive tsunami after the 8.8 earthquake off Chile, but fortunately only 3-foot tsunami waves hit the state's shores.
The DART system consists of surface-level buoys connected by mooring lines to ocean-floor-anchored recording devices that monitor seismic activity. Data from the recording devices is transmitted to a satellite in 15-minute intervals until an event triggers transmissions at 15-second intervals. The satellite then delivers that data to two tsunami warning centers based in Alaska and Hawaii, respectively. The centers are responsible for warning U.S. coastal states, island territories, and over 90 countries when a tsunami threat occurs.
The buoys, however, are expensive and temperamental. Last year, DART operation and maintenance cost $12 million, or 28 percent, of NOAA's total tsunami budget for the fiscal year.
Reliability is another problem. At any one time, the NOAA reported that data from the buoys was available about 84 percent of the time and one to two buoy outages occur each month. There's two primarily reasons for this: human error and "Old Man Winter."
Most buoy outages occur due to problems with mooring lines. "According to data from NOAA's National Data Buoy Center... failure of mooring lines accounted for almost 60 percent of DART buoy outages from December 2005 to November 2009," the GAO reports. "Center officials told us that mooring lines fail for a variety of reasons, including ship collisions and vessels that tie up to a buoy."
Winter makes it difficult to keep the buoys working because the NOAA can't make its regular maintenance rounds because of harsh ocean conditions.
The NOAA told the GAO it wants to significantly improve its buoy network's data availability rate. Currently the NOAA is trying to identify stronger mooring materials while it also explores moving some buoys to less hostile waters.
These improvements are critical, the GAO explains, because "[w]hen DART buoys are out of service, they cannot detect tsunamis or transmit data to the tsunami warning centers."
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♦ Graphs from GAO