IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Oral Presentation 1760
National ocean service operation of tide stations in support of tsunami
detection
Mr. Stephen Gill
Allison Allen, Natalia Donoho, Stephen Gill, Tom Mero, Rolin Meyer, Manoj
Samant, Robert Aspinall
The United States National Oceanic and Atmospheric Administration (NOAA) funds several water level
observation networks in support of operational tsunami warning capability. These observing systems
include NOAA-funded stations operated by the University of Hawaii Sea Level Center, stations operated
by the NOAA Tsunami Warning Centers (TWCs), the NOAA-operated DART network, and the stations of
the NOAA National Water level Observation Network (NWLON). This paper describes the NOAA National
Ocean Service (NOS), Center for Operational Oceanographic Products and Services (CO-OPS)
contribution to tsunami warning. CO-OPS is responsible for operating the NWLON which has supported
tsunami warning since 1948. NOS continues to expand the NWLON to collect multi-purpose data for a
variety of applications, including real-time water levels for navigation, sea level trends, habitat
restoration, computation of tidal datums, and coastal hazard mitigation. After the December 2004
Indian Ocean tsunami, CO-OPS was tasked to coordinate with the TWCs to expand and upgrade the
tsunami warning capabilities of the NWLON. A plan was developed to upgrade existing NWLON stations
with new Data Collection Platforms (DCPs), implement data formats, and fill observation gaps. Work
began in 2005 to upgrade 33 existing water level stations and install 16 new stations in priority areas in
the Pacific Ocean and the Caribbean . By September 2006, all 33 targeted upgrades had been
completed, as well as 15 of the 16 planned installations. And by September 2007, CO-OPS plans to have
completed the upgrade of all coastal NWLON stations with new DCPs to satisfy tsunami requirements.
As of January 2007, a total of 100 NWLON stations are operating in support of the National Weather
Service (NWS)s tsunami warning capabilities. Even though this information will still be transmitted via
the Geostationary Operational Environmental Satellite (GOES) for both the primary and backup DCPs,
for the first time the upgraded DCPs will be transmitting 1-minute averaged water levels every six
minutes. 6 and 1-minute data are available to the TWCs directly through GOES, through remote phone
dial-in, and through the CO-OPS web page. These stations also store 15-second data on a flash drive for
post event analyses and modeling. The 15-second data can be manually downloaded from the station
itself or remotely using the DCPs modem. The strategy developed by CO-OPS and the TWCs has
involved more than just the expansion of the NWLON and new hardware, but an expansion of a total
capability, as evidenced by the CO-OPS support to computing harmonic constants for each DART buoy
site, so that effective de-tiding can take place for resolution of the tsunami signals.
Keywords: noaa, tide, station