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A tsunami warning system is a system to detect tsunamis and issue warnings to prevent loss of life and property. 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 areas. Image File history File links Please see the file description page for further information. ... See Coastal management. ... The tsunami that struck Malé in the Maldives on December 26, 2004. ...

There are two distinct types: international tsunami warning systems, and regional warning systems. Both depend on the fact that, while tsunamis travel at between 500 and 1,000 km/h (around 0.14 and 0.28 km/s) in open water, earthquakes can be detected almost at once as seismic waves travel with a typical speed of 4 km/s (around 14,400 km/h). This gives time for a possible tsunami forecast to be made and warnings to be issued to threatened areas, if warranted. Unfortunately, until a reliable model is able to predict which earthquakes will produce significant tsunamis, this approach will produce many more false alarms than verified warnings. In the currect operational paradigm, the seismic alerts are used to send out the watches and warnings. Then, data from observed sea level height (either shore based via tide gauges or deep ocean DART buoys) are used to verify the existence of a tsunami. Other systems have been proposed to augment the warning paradigm. For example, it has been suggested that the duration and frequency content of t-wave energy (which is earthquake energy trapped in the ocean SOFAR channel) is indicative of an earthquakes tsunami potential [Salzberg, 2006]. The first rudimentary system to alert communities of an impending tsunami was attempted in Hawaii in the 1920s. More advanced systems were developed in the wake of the April 1, 1946 and May 23, 1960 tsunamis which caused massive devastation in Hilo, Hawaii. Body waves and surface waves Earthquake wave paths p-wave and s-wave from seismograph A seismic wave is a wave that travels through the Earth, most often as the result of a tectonic earthquake, sometimes from an explosion. ... Official language(s) English, Hawaiian Capital Honolulu Largest city Honolulu Area  Ranked 43rd  - Total 10,931 sq mi (29,311 km²)  - Width n/a miles (n/a km)  - Length 1,522 miles (2,450 km)  - % water 41. ... 1920 (MCMXX) was a leap year starting on Thursday. ... April 1 is the 91st day of the year (92nd in leap years) in the Gregorian calendar. ... Year 1946 (MCMXLVI) was a common year starting on Tuesday (link will display full 1946 calendar) of the Gregorian calendar. ... is the 143rd day of the year (144th in leap years) in the Gregorian calendar. ... 1960 (MCMLX) was a leap year starting on Friday (the link is to a full 1960 calendar). ... Hilo (pronounced IPA: ) is a coastal city in the State of HawaiÊ»i, and is the largest community on the island of HawaiÊ»i. ...

International warning systems (IOC)

Pacific Ocean

Tsunami warnings for most of the Pacific Ocean are issued by the Pacific Tsunami Warning Center (PTWC), operated by the United States's NOAA in Ewa Beach, Hawaii. NOAA's West Coast/Alaska Tsunami Warning Center (WC/ATWC) in Palmer, Alaska issues warnings for the west coast of North America, including Alaska, Canada, and the western coterminous United States. PTWC was established in 1949, following the 1946 Aleutian Island earthquake and a tsunami that resulted in 165 casualties on Hawaii and Alaska; WC/ATWC was founded in 1967. International coordination is achieved through the International Coordination Group for the Tsunami Warning System in the Pacific, established by the Intergovernmental Oceanographic Commission of UNESCO.[1] Tsunameter and buoys used by DART system The Pacific Tsunami Warning Center (PTWC), operated by NOAA in Ewa Beach, Hawaii, USA, is one of two tsunami warning centers in the United States. ... The National Oceanic and Atmospheric Administration (NOAA) is a scientific agency of the United States Department of Commerce focused on the conditions of the oceans and the atmosphere. ... Ewa Beach is a town and census-designated place (CDP) located in Ewa District and the City & County of Honolulu along the leeward coast of Oahu in Hawaii. ... Palmer depot with a narrow gauge locomotive. ... 1949 (MCMXLIX) was a common year starting on Saturday (the link is to a full 1949 calendar). ... Year 1946 (MCMXLVI) was a common year starting on Tuesday (link will display full 1946 calendar) of the Gregorian calendar. ... Aleutian Island earthquake was an earthquake near the Aleutian Islands on April 1, 1946, and was followed by a Pacific-wide tsunami wave. ... The Intergovernmental Oceanographic Commission was established by resolution 2. ... UNESCO (United Nations Educational, Scientific and Cultural Organization) is a specialized agency of the United Nations established in 1945. ...

Indian Ocean (ICG/IOTWS)

Main article: Indian Ocean Tsunami Warning System

After the 2004 Indian Ocean Tsunami which killed almost 230,000 people, a United Nations conference was held in January 2005 in Kobe, Japan, and decided that as an initial step towards an International Early Warning Programme, the UN should establish an Indian Ocean Tsunami Warning System.[2] The Indian Ocean Tsunami Warning System is a tsunami warning system set up to provide warning to inhabitants of nations bordering the Indian Ocean of approaching tsunamis. ... The 2004 Indian Ocean earthquake, known by the scientific community as the Sumatra-Andaman earthquake,[1] was a great undersea earthquake that occurred at 00:58:53 UTC (07:58:53 local time) December 26, 2004 with an epicentre off the west coast of Sumatra, Indonesia. ... The foundation of the U.N. The United Nations (UN) is an international organization whose stated aims are to facilitate co-operation in international law, international security, economic development, social progress and human rights issues. ... Kobe ) is the capital city of Hyōgo Prefecture and a prominent port city in Japan with a population of about 1. ... The International Early Warning Programme (IEWP), was first proposed at the Second International Conference on Early Warning in 2003 in Bonn, Germany. ... The Indian Ocean Tsunami Warning System is a tsunami warning system set up to provide warning to inhabitants of nations bordering the Indian Ocean of approaching tsunamis. ...

North Eastern Atlantic, the Mediterranean and connected Seas (ICG/NEAMTWS)

Main article: North Eastern Atlantic, the Mediterranean and connected Seas Tsunami Warning System

The First Session of the Intergovernmental Coordination Group for the Tsunami Early Warning and Mitigation System in the North Eastern Atlantic, the Mediterranean and connected Seas (ICG/NEAMTWS), established by the Intergovernmental Oceanographic Commission of UNESCO Assembly during its 23rd Session in June 2005, through Resolution XXIII.14, took place in Rome on 21st and 22nd November, 2005. The Meeting, hosted by the Government of Italy (Italian Ministry of Foreign Affairs and Ministry for Environment and Protection of the Territory), was attended by more than 150 participants from 24 countries, 13 organizations and numerous observers. The Intergovernmental Oceanographic Commission was established by resolution 2. ... UNESCO (United Nations Educational, Scientific and Cultural Organization) is a specialized agency of the United Nations established in 1945. ...

Regional warning systems

Regional (or local) warning system centres use seismic data about nearby earthquakes to determine if there is a possible local threat of a tsunami. Such systems are capable of issuing warnings to the general public (via public address systems and sirens) in less than 15 minutes. Although the epicenter and moment magnitude of an underwater quake and the probable tsunami arrival times can be quickly calculated, it is almost always impossible to know whether underwater ground shifts have occurred which will result in tsunami waves. As a result, false alarms can occur with these systems, but due to the highly localised nature of these extremely quick warnings, disruption is small. Seismology (from the Greek seismos = earthquake and logos = word) is the scientific study of earthquakes and the movement of waves through the Earth. ... Global earthquake epicenters, 1963–1998. ... The epicenter is directly above the earthquakes focus. ... The moment magnitude scale (a successor to the Richter Scale), was introduced in 1979 by Tom Hanks and Hiroo Kanamori and is used by seismologists to compare the energy released by earthquakes. ...

Conveying the warning

Japanese TV warning of tsunamis, September 2004

Detection and prediction of tsunamis is only half the work of the system. Of equal importance is the ability to warn the populations of the areas that will be affected. All tsunami warning systems feature multiple lines of communications (such as e-mail, fax, radio and telex, often using hardened dedicated systems) enabling emergency messages to be sent to the emergency services and armed forces, as well to population alerting systems (eg sirens). Japanese TV warning of tsunamis, September 2004 This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Japanese TV warning of tsunamis, September 2004 This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Wikipedia does not yet have an article with this exact name. ... A Samsung fax machine Fax (short for facsimile, from Latin fac simile, make similar, i. ... Teletype machines in World War II A teleprinter (teletypewriter, teletype or TTY for TeleTYpe/TeleTYpewriter) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ... Emergency services are public services that deal with emergencies and other aspects of Public Safety. ... The armed forces of a state are its government sponsored defense and fighting forces and organizations. ... It has been suggested that Fire siren be merged into this article or section. ...

Shortcomings

No system can protect against a very sudden tsunami. A devastating tsunami occurred off the coast of Hokkaidō in Japan as a result of an earthquake on July 12, 1993. As a result, 202 people on the small island of Okushiri, Hokkaido lost their lives, and hundreds more were missing or injured. This tsunami struck just three to five minutes after the quake, and most victims were caught while fleeing for higher ground and secure places after surviving the earthquake.   literally North Sea Circuit, Ainu: Mosir), formerly known as Ezo, Yezo, Yeso, or Yesso, is the second largest island and largest prefecture of Japan. ... July 12 is the 193rd day of the year (194th in leap years) in the Gregorian calendar. ... Year 1993 (MCMXCIII) was a common year starting on Friday (link will display full 1993 Gregorian calendar). ... Okushiri (奥尻町; -chou) is a town encompassing all of Okushiri Island, located in Okushiri District, Hiyama, Hokkaido, Japan. ...

While there remains the potential for sudden devastation from a tsunami, warning systems can be effective. For example if there were a very large subduction zone earthquake (magnitude 9.0) off the west coast of the United States, people in Japan, for example, would have more than 12 hours (and likely warnings from warning systems in Hawaii and elsewhere) before any tsunami arrived, giving them some time to evacuate areas likely to be affected. Categories: Geology stubs | Plate tectonics ... An earthquake is the result from the sudden release of stored energy in the Earths crust that creates seismic waves. ... The moment magnitude scale (a successor to the Richter Scale), was introduced in 1979 by Tom Hanks and Hiroo Kanamori and is used by seismologists to compare the energy released by earthquakes. ...

External links

• Space Applications for Disaster Monitoring
• How does the Tsunami Warning System Work? from the NOAA Tsunami website
• Pacific Tsunami Warning Center
• West Coast and Alaska Tsunami Warning Center
• DART
• bigwavealert volunteer based not-for-profit sms warning system
• Tsunami Alarm System to mobile phones for everybody
• Tsunami Detector for Indian Ocean Web & Mobile application that reports probability of tsunami occurrences from LIVE USGS data.
• Envirtech Tsunami Warning System, based on real time seafloor observatories measuring seismic waves and sea levels
• Integrated Tsunami Watcher Service Web & SMS based Free service.
• NOAA Tsunami Warnings and Forecasts
• Indian Ocean Tsunami Warning Center