Performance of the First Year of the Completed U.S. Operational Deep- Sea Tsunameter Network

摘要

In March 2008, the National Oceanic and Atmospheric Administration's (NOAA) National Data Buoy Center (NDBC) completed the deployment of the full 39- station network of deep-sea tsunameters bolstering the U.S. tsunami warning system. This vast network of 39 stations provides coastal communities in the Pacific, Atlantic, Caribbean and the Gulf of Mexico with faster and more accurate tsunami warnings. The tsunameters employ the patented technology of the second generation Deep-ocean Assessment and Reporting of Tsunamis (DART II). A full year of operating the completed network provided a host of challenges and accomplishments. Data availability statistics missed the operating goal of 80%, primarily due to a rash of mooring failures. Most of these failures occurred in regions of strong ocean currents - the Kuroshio Current, the Loop Current of the Gulf of Mexico, and the Gulf Stream. Stations in the western North Pacific Ocean experienced prolonged outages because of the great distances from staging areas and persistent stormy weather and their proximity to major storm tracks. However, in 2007 the mooring and system at station 42407, in the Caribbean, had exceeded design specifications by weathering the passage of Hurricane Dean, when it was a Category 4 hurricane. In the spring and summer of 2009, a series of ambitious service cruises will return the network to nearly full operating capability. Focusing on ways to reduce future outages, NDBC undertook a number of engineering initiatives, including an intensive investigation into the mooring failures and deployed several new mooring types for evaluation and obtained warehouse space in Guam to reduce logistical requirements.