Deep-ocean Assessment and Reporting of Tsunamis
Encyclopedia
The Deep-ocean Assessment and Reporting of Tsunamis (officially abbreviated and trademarked as DART®) system is a component of an enhanced tsunami warning system
.
and a seafloor bottom pressure recording (BPR) package that detects pressure
changes caused by tsunamis. The surface buoy receives transmitted information from the BPR via an acoustic link and then transmits data to a satellite, which retransmits the data to ground stations for immediate dissemination to NOAA's Tsunami Warning Centers, NOAA's National Data Buoy Center, and NOAA's Pacific Marine Environmental Laboratory
(PMEL).
The Iridium commercial satellite phone
network is used for communication between 31 of the buoys.
When on-board software identifies a possible tsunami, the station leaves standard mode and begins transmitting in event mode. In standard mode, the station reports water temperature and pressure (which are converted to sea-surface height) every 15 minutes. At the start of event mode, the buoy reports measurements every 15 seconds for several minutes, followed by 1-minute averages for 4 hours.
The first-generation DART I stations had one-way communication ability, and relied solely on the software's ability to detect a tsunami to trigger event mode and rapid data transmission. In order to avoid false positives, the detection threshold was set relatively high, presenting the possibility that a tsunami with a low amplitude could fail to trigger the station.
The second-generation DART II is equipped for two-way communication, allowing tsunami forecasters to place the station in event mode in anticipation of a tsunami's arrival.
, with the first prototype deployed off the coast of Oregon
in 1995. In 2004, the DART® stations were transitioned from research at PMEL to operational service at the National Data Buoy Center
(NDBC), and PMEL and NDBC received the Department of Commerce Gold Medal
"for the creation and use of a new moored buoy system to provide accurate and timely warning information on tsunamis".
In the wake of the 2004 Indian Ocean earthquake
and its subsequent tsunami
s, plans were announced to deploy an additional 32 DART II buoys around the world. These would include stations in the Caribbean
and Atlantic Ocean
for the first time.
The United States' array was completed in 2008 totaling 39 stations in the Pacific Ocean, Atlantic Ocean, and Caribbean Sea. The international community has also taken an interest in DART buoys and as of 2009 Australia, Chile, Indonesia and Thailand have deployed DART buoys to use as part of each country's tsunami warning system.
Tsunami warning system
A Tsunami warning system is used to detect tsunamis in advance and issue warnings to prevent loss of life and damage. It consists of two equally important components: a network of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to permit evacuation of coastal...
.
Stations
Each DART® station consists of a surface buoyBuoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...
and a seafloor bottom pressure recording (BPR) package that detects pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
changes caused by tsunamis. The surface buoy receives transmitted information from the BPR via an acoustic link and then transmits data to a satellite, which retransmits the data to ground stations for immediate dissemination to NOAA's Tsunami Warning Centers, NOAA's National Data Buoy Center, and NOAA's Pacific Marine Environmental Laboratory
Pacific Marine Environmental Laboratory
The Pacific Marine Environmental Laboratory is a laboratory in the National Oceanic and Atmospheric Administration /Office of Oceanic and Atmospheric Research ....
(PMEL).
The Iridium commercial satellite phone
Satellite phone
A satellite telephone, satellite phone, or satphone is a type of mobile phone that connects to orbiting satellites instead of terrestrial cell sites...
network is used for communication between 31 of the buoys.
When on-board software identifies a possible tsunami, the station leaves standard mode and begins transmitting in event mode. In standard mode, the station reports water temperature and pressure (which are converted to sea-surface height) every 15 minutes. At the start of event mode, the buoy reports measurements every 15 seconds for several minutes, followed by 1-minute averages for 4 hours.
The first-generation DART I stations had one-way communication ability, and relied solely on the software's ability to detect a tsunami to trigger event mode and rapid data transmission. In order to avoid false positives, the detection threshold was set relatively high, presenting the possibility that a tsunami with a low amplitude could fail to trigger the station.
The second-generation DART II is equipped for two-way communication, allowing tsunami forecasters to place the station in event mode in anticipation of a tsunami's arrival.
History
The DART buoy technology was developed at PMELPacific Marine Environmental Laboratory
The Pacific Marine Environmental Laboratory is a laboratory in the National Oceanic and Atmospheric Administration /Office of Oceanic and Atmospheric Research ....
, with the first prototype deployed off the coast of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
in 1995. In 2004, the DART® stations were transitioned from research at PMEL to operational service at the National Data Buoy Center
National Data Buoy Center
The National Data Buoy Center is a part of the National Oceanic and Atmospheric Administration's National Weather Service...
(NDBC), and PMEL and NDBC received the Department of Commerce Gold Medal
Gold Medal
Gold Medal is the sixth studio album by the American hard rock band The Donnas, released in 2004 on Atlantic Records. It was one of the first albums released in the DualDisc format, but was recalled due to a mastering error which resulted in the final track being partially omitted from the CD...
"for the creation and use of a new moored buoy system to provide accurate and timely warning information on tsunamis".
In the wake of the 2004 Indian Ocean earthquake
2004 Indian Ocean earthquake
The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at 00:58:53 UTC on Sunday, December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra-Andaman earthquake...
and its subsequent tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
s, plans were announced to deploy an additional 32 DART II buoys around the world. These would include stations in the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
and Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
for the first time.
The United States' array was completed in 2008 totaling 39 stations in the Pacific Ocean, Atlantic Ocean, and Caribbean Sea. The international community has also taken an interest in DART buoys and as of 2009 Australia, Chile, Indonesia and Thailand have deployed DART buoys to use as part of each country's tsunami warning system.
See also
- Global Sea Level Observing SystemGlobal Sea Level Observing SystemThe Global Sea Level Observing System is an Intergovernmental Oceanographic Commission program whose purpose is to measure sea level globally for long-term climate change studies. The program's purpose has changed since the 2004 Indian Ocean earthquake and the program now collects realtime...
- Tsunami warning systemTsunami warning systemA Tsunami warning system is used to detect tsunamis in advance and issue warnings to prevent loss of life and damage. It consists of two equally important components: a network of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to permit evacuation of coastal...
- TsunamiTsunamiA tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
- NOAA Center for Tsunami ResearchNOAA Center for Tsunami ResearchThe NOAA Center for Tsunami Research , located at the Pacific Marine Environmental Laboratory in Seattle, WA, performs research in support of tsunami forecast models to increase the speed and accuracy of operational forecasts and warnings, tsunami inundation models to predict tsunami impacts on...
External links
- NOAA NDBC Deep-ocean Assessment and Reporting of Tsunamis (DART®)
- NOAA NCTR Deep-ocean Assessment and Reporting of Tsunamis (DART®)
- Realtime DART buoy data from the National Data Buoy CenterNational Data Buoy CenterThe National Data Buoy Center is a part of the National Oceanic and Atmospheric Administration's National Weather Service...
- High-resolution archived data from the National Geophysical Data CenterNational Geophysical Data CenterThe National Geophysical Data Center provides scientific stewardship, products and services for geophysical data describing the solid earth, marine, and solar-terrestrial environment, as well as earth observations from space....
- Social & Economic Benefits of the DART system from "NOAA Socioeconomics" website initiative
- NOAA Tsunami website
- National Tsunami Hazard Mitigation Program