Tsunami warning system

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Evacuation route sign in a low-lying coastal area on the West Coast of the United States Tsunami evac sign Seaside Oregon.JPG
Evacuation route sign in a low-lying coastal area on the West Coast of the United States

A tsunami warning system (TWS) is used to detect tsunamis in advance and issue the warnings to prevent loss of life and damage to property. It is made up of two equally important components: a network of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to permit evacuation of the coastal areas. There are two distinct types of tsunami warning systems: international and regional. When operating, seismic alerts are used to instigate the watches and warnings; then, data from observed sea level height (either shore-based tide gauges or DART buoys) are used to verify the existence of a tsunami. Other systems have been proposed to augment the warning procedures; 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 earthquake's tsunami potential. [1]

Contents

History and forecasting

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 (caused by the 1946 Aleutian Islands earthquake) and May 23, 1960 (caused by the 1960 Valdivia earthquake) tsunamis which caused massive devastation in Hilo, Hawaii. 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. 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.

International systems (IS)

Pacific Ocean

Japanese Tsunami warning sign TsunamiHazardSign.svg
Japanese Tsunami warning sign

Tsunami warnings (SAME code: TSW) for most of the Pacific Ocean are issued by the Pacific Tsunami Warning Center (PTWC), operated by the United States NOAA in Ewa Beach, Hawaii. NOAA's National Tsunami Warning Center (NTWC) in Palmer, Alaska issues warnings for North America, including Alaska, British Columbia, Oregon, California, the Gulf of Mexico, and the East coast. The PTWC was established in 1949, following the 1946 Aleutian Island earthquake and a tsunami that resulted in 165 casualties on Hawaii and in Alaska; NTWC 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. [2]

Chile

In 2005, Chile started to implement the Integrated Plate boundary Observatory Chile (IPOC) [3] which in the following years become a network of 14 multiparameter stations for monitoring the 600-km seismic distance between Antofagasta and Arica. Each station was provided with broadband seismometer, accelerometer, GPS antenna. In four cases, it was installed a short-base tiltmeter (pendulum). Some stations were ubicated underground at a depth of 3–4 meters. The network completed the tidal gauge of the Hydrographic and Oceanographic Service of the Chilean Navy. [4]

The long-base tiltmeters (LBTs) and the STS2 seismometer of the IPOC recorded a series of long-period signals some days after the 2010 Maule earthquake. The same effect was registered by broadband seismometers of India and Japan some days after the 2004 Indian Ocean earthquake and tsunami. Simulations held in 2013 on historical data highlighted "tiltmeters and broadband seismometers are thus valuable instruments for monitoring tsunamis in complement with tide gauge arrays." In the case of the 2010 Maule earthquake, tilt-sensors observed a discriminating signal "starting 20 min before the arrival time of the tsunami at the nearest point on the coastline." [4]

Indian Ocean (ICG/IOTWMS)

Tsunami Early Warning Tower board in Hikkaduwa, Sri Lanka Tsunami-warning-centre hikkaduwa sri-lanka.jpg
Tsunami Early Warning Tower board in Hikkaduwa, Sri Lanka

After the 2004 Indian Ocean Tsunami which killed almost 250,000 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. This resulted in a warning system for Indonesia and other affected areas. Indonesia's system fell out of service in 2012 because the detection buoys were no longer operational.[ citation needed ] Tsunami prediction was then limited to detection of seismic activity, with no system to predict tsunamis based on volcanic eruptions.

Indonesia was hit by tsunamis in September and December 2018. The December 2018 tsunami was caused by a volcano. [5] Sea level sensors were then installed by the Indonesian government to fill the prediction gap. [6]

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

The First United Session of the Inter-governmental 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 21 and 22 November 2005.

The meeting, hosted by the Government of Italy (the Italian Ministry of Foreign Affairs and the Italian Ministry for the Environment and Protection of Land and Sea), was attended by more than 150 participants from 24 countries, 13 organizations and numerous observers.

Caribbean

A Caribbean-wide tsunami warning system was planned to be instituted by the year 2010, by representatives of Caribbean nations who met in Panama City in March 2008. Panama's last major tsunami killed 4,500 people in 1882. [7] Barbados has said it will review or test its tsunami protocol in February 2010 as a regional pilot. [8] [ needs update ]

Regional warning systems

Tsunami warning system in East Timor 1 Tsunamiwarnsystem in Dili.jpg
Tsunami warning system in East Timor

Regional (or local) warning system centers use seismic data about nearby recent 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 the disruption is small, which makes sense due to the highly localized nature of these extremely quick warnings, in combination with how difficult it would be for a false alarm to affect more than a small area of the system. Real tsunamis would affect more than just a small portion. [ citation needed ]

Japan

Evacuation route sign on the pavement in Kamakura, Japan Tsunami evacuation route sign on the road, Kamakura, 2016.jpg
Evacuation route sign on the pavement in Kamakura, Japan

Japan has a nationwide tsunami warning system. The system usually issues the warning minutes after an Earthquake Early Warning (EEW) is issued, should there be expected waves. [9] [10] The tsunami warning was issued within 3 minutes with the most serious rating on its warning scale during the 2011 Tōhoku earthquake and tsunami; it was rated as a "major tsunami", being at least 3 m (9.8 ft) high. [10] [11] An improved system was unveiled on March 7, 2013 following the 2011 disaster to better assess imminent tsunamis. [12] [13]

India

India is one of the 5 countries to have the most advanced tsunami warning systems in the world. [14] In 2004, right after being hit by an earthquake in Sumatra, a massive tsunami devastated the coasts of India, [15] prompting the Government of India to set up the INCOIS (Indian National Centre for Ocean Information Services). [16] The center is an autonomous organization of the Government of India, under the Ministry of Earth Sciences, located in Pragathi Nagar, Hyderabad, India. This center offers ocean information and advisory services to society, industry, government bodies in areas like Tsunami warning, ocean state forecast, fishing zones and more. [17]

This center receives data from over 35 sea level tide gauges at intervals of 5 minutes. [18] Along with this it receives data from wave rider buoys, bottom pressure readers (BPRs) and a network of seismographs that have been installed at various locations in the IOR (Indian Ocean Region). The Indian Tsunami Buoy Type 1 System [19] consists of 2 units - a surface buoy and a bottom pressure reader (BPR). Communication between BPR and the surface buoy is through acoustic modems and the surface buoys use the INSAT satellite system to communicate readings back to shore stations. The Tsunami warning station collates information from 17 seismic stations of the Indian Meteorological Department (IMD), 10 stations of Wadia Institute of Himalayan Geology (WIHG) [20] and more than 300 international stations. INDOFOS (INDian Ocean FOrecasting System) is a service that forecasts the ocean state and is capable of predicting surface and sub surface features and states of the Indian Ocean. [21] These forecasts are made accessible through Information centers, Radio, local digital sign boards, websites, TV channels and subscription services. Oceansat 2 system is a collection of earth observation satellites operated by ISRO [22] in conjunction with Oceansat ground station that covers an area of 5000 km radius around India and is capable of monitoring sea flora and fauna along with oceanic features like meandering patterns, eddies, rings, upwelling and others. Oceansat-2 was successfully deployed to predict the landfall and mitigate the effects of Cyclone Phailin, in October 2013. [23]

Conveying the warning

Mast with warning system, and sign detailing escape routes, on the coast of Okumatsushima, Miyagi prefecture, Japan (this coast was severely hit by the 2011 tsunami) Okumatsushima tsunami P1130317 rotated.jpg
Mast with warning system, and sign detailing escape routes, on the coast of Okumatsushima, Miyagi prefecture, Japan (this coast was severely hit by the 2011 tsunami)

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 Cell Broadcast, SMS, e-mail, fax, radio, texting and telex, often using hardened dedicated systems)[ citation needed ] enabling emergency messages to be sent to the emergency services and armed forces, as well to population-alerting systems (e.g. sirens) and systems like the Emergency Alert System. [24]

Shortcomings

With the speed at which tsunami waves travel through open water, no system can protect against a very sudden tsunami, where the coast in question is too close to the epicenter. 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.[ citation needed ] 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. This was also the case in Aceh, Indonesia.[ citation needed ]

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 (moment magnitude 9.0) off the west coast of the United States, people in Japan, would therefore 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.

See also

Related Research Articles

<span class="mw-page-title-main">Earthquake</span> Sudden movement of the Earths crust

An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.

<span class="mw-page-title-main">Tsunami</span> Series of water waves caused by the displacement of a large volume of a body of water

A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event.

<span class="mw-page-title-main">2004 Indian Ocean earthquake and tsunami</span> Earthquake and subsequent tsunami in the Indian Ocean

On 26 December 2004, at 07:58:53 local time (UTC+7), a major earthquake with a magnitude of 9.1–9.3 Mw struck with an epicentre off the west coast of northern Sumatra, Indonesia. The undersea megathrust earthquake, known by the scientific community as the Sumatra–Andaman earthquake, was caused by a rupture along the fault between the Burma Plate and the Indian Plate, and reached a Mercalli intensity up to IX in some areas.

<span class="mw-page-title-main">Pacific Tsunami Warning Center</span> One of two tsunami warning centers that are operated by NOAA, located on Ford Island, Hawaii

The Pacific Tsunami Warning Center (PTWC), located on Ford Island, Hawaii, is one of two tsunami warning centers in the United States, covering Hawaii, Guam, American Samoa and the Northern Mariana Islands in the Pacific, as well as Puerto Rico, the U.S. Virgin Islands and the British Virgin Islands in the Caribbean Sea. Other parts of the United States are covered by the National Tsunami Warning Center.

<span class="mw-page-title-main">Deep-ocean Assessment and Reporting of Tsunamis</span> Component of an enhanced tsunami warning system

Deep-ocean Assessment and Reporting of Tsunamis (DART) is a component of an enhanced tsunami warning system.

The Indian Ocean Tsunami Warning System was set up to provide warning to inhabitants of nations bordering the Indian Ocean of approaching tsunamis. The tsunami warning system has been in use since the mid-2000s.

<span class="mw-page-title-main">2005 Nias–Simeulue earthquake</span> 2005 earthquake in Sumatra, Indonesia

The 2005 Nias–Simeulue earthquake occurred on 28 March off the west coast of northern Sumatra, Indonesia. At least 915 people were killed, mostly on the island of Nias. The event caused panic in the region, which had already been devastated by the massive tsunami triggered by the 2004 Indian Ocean earthquake, but this earthquake generated a relatively small tsunami that caused limited damage. It was the third most powerful earthquake since 1965 in Indonesia.

<span class="mw-page-title-main">Central Weather Administration</span> Meteorological service of the Republic of China (Taiwan)

The Central Weather Administration is the government meteorological research and forecasting institution of the Republic of China (Taiwan). In addition to meteorology, the Central Weather Administration also makes astronomical observations, reports on sea conditions, and conducts research into seismology and provides earthquake reports. The Central Weather Administration is headquartered in Taipei City and is administered under the Ministry of Transportation and Communications.

The Ministry of Earth Sciences was formed on 29 January 2006 from a merger of the India Meteorological Department (IMD), the National Centre for Medium Range Weather Forecasting (NCMRWF), the Indian Institute of Tropical Meteorology, Pune (IITM), the Earth Risk Evaluation Centre (EREC) and the Ministry of Ocean Development.

<span class="mw-page-title-main">September 2007 Sumatra earthquakes</span> Earthquakes affecting Indonesia

The September 2007 Sumatra earthquakes were a series of megathrust earthquakes that struck the Sunda Trench off the coast of Sumatra, Indonesia, with three of magnitude 7 or greater. A series of tsunami bulletins was issued for the area. The most powerful of the series had a magnitude of 8.5, which makes it in the top 20 of the largest earthquakes ever recorded on a seismograph.

Indian National Center for Ocean Information Services (INCOIS) is an autonomous organization of the Government of India, under the Ministry of Earth Sciences, located in Pragathi Nagar, Hyderabad. ESSO-INCOIS was established as an autonomous body in 1998 under the Ministry of Earth Sciences (MoES) and is a unit of the Earth System Science Organization (ESSO). ESSO- INCOIS is mandated to provide the best possible ocean information and advisory services to society, industry, government agencies and the scientific community through sustained ocean observations and constant improvements through systematic and focussed research.

<span class="mw-page-title-main">Earthquake Early Warning (Japan)</span> Japanese system to alert of impending earthquakes

In Japan, the Earthquake Early Warning (EEW) is a warning issued when an earthquake is detected by multiple seismometers. These warnings are primarily issued by the Japan Meteorological Agency (JMA), with guidance on how to react to them.

<span class="mw-page-title-main">2010 Mentawai earthquake and tsunami</span> 2010 Indonesian earthquake and tsunami

The 2010 Mentawai earthquake occurred with a moment magnitude of 7.8 on 25 October off the western coast of Sumatra at 21:42 local time. The earthquake occurred on the same fault that produced the 2004 Indian Ocean earthquake. It was widely felt across the provinces of Bengkulu and West Sumatra and resulted in a substantial localized tsunami that struck the Mentawai Islands.

<span class="mw-page-title-main">Timeline of the 2004 Indian Ocean earthquake and tsunami</span>

Although National Oceanic and Atmospheric Administration (NOAA) scientists at the Pacific Tsunami Warning Center (PTWC) in Hawaii eventually issued warnings of a possible tsunami from the large earthquake off Sumatra, the waves outran notification systems at jet speeds of 500 mph (804 km/h), catching hundreds of thousands of people unaware. The following is a timeline of the 2004 Indian Ocean earthquake. All times are Coordinated Universal Time (UTC), on Sunday, 26 December 2004.

<span class="mw-page-title-main">2011 Tōhoku earthquake and tsunami</span> Megathrust earthquake off Japans east coast

On 11 March 2011, at 14:46 JST, a Mw 9.0–9.1 undersea megathrust earthquake occurred in the Pacific Ocean, 72 km (45 mi) east of the Oshika Peninsula of the Tōhoku region. It lasted approximately six minutes, causing a tsunami. It is sometimes known in Japan as the "Great East Japan Earthquake", among other names. The disaster is often referred to by its numerical date, 3.11.

<span class="mw-page-title-main">National Tsunami Warning Center</span> Detects and analyzes earthquakes worldwide, issuing warnings to local officials

The National Tsunami Warning Center (NTWC) is one of two tsunami warning centers in the United States, covering all coastal regions of the United States and Canada, except Hawaii, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands. Until 2013, it was known as the West Coast and Alaska Tsunami Warning Center.

The 2012 Indian Ocean earthquakes were magnitude 8.6 and 8.2 Mw  undersea earthquakes that struck near the Indonesian province of Aceh on 11 April at 15:38 local time. Initially, authorities feared that the initial earthquake would cause a tsunami and warnings were issued across the Indian Ocean; however, these warnings were subsequently cancelled. These were unusually strong intraplate earthquakes and the largest strike-slip earthquake ever recorded.

<span class="mw-page-title-main">Shailesh Nayak</span> Indian oceanographer

Shailesh Nayak is an Indian scientist and is currently Director of the National Institute of Advanced Studies, Chancellor of TERI School of Advanced Studies and Distinguished Scientist in the Ministry of Earth Sciences. He was the Chair of the Earth System Science Organization (ESSO) and Secretary to the Government of India for Ministry of Earth Sciences (MoES) Indian government, between August 2008 – 2015. He was also the Chairman of Earth Commission in India. He served as the interim chairman of ISRO between 31 December 2014 and 11 January 2015.

<span class="mw-page-title-main">Tsunami Advisory Center of the Ministry of National Resources</span>

The Tsunami Advisory Center of the Ministry of National Resources is a Chinese administrative agency that aims to mitigate tsunami damage in the coastal areas of China. The agency is also known as the UNESCO Intergovernmental Oceanic Committee South China Sea Regional Tsunami Warning Center, which is abbreviated as the South China Sea Tsunami Advisory Center (SCSTAC). It was founded in 2013 and is a subsidiary of the Ministry of Natural Resources of the People's Republic of China and the National Marine Environmental Forecasting Center.

References

  1. ↑ Salzberg, 2006
  2. ↑ "IOC Oceans | United Nations Educational, Scientific and Cultural Organization". Ioc.unesco.org. Archived from the original on 2005-05-15. Retrieved 2018-10-02.
  3. ↑ "Official website of the Integrated Plate boundary Observatory Chile". Archived from the original on 2017-07-12. Retrieved 2020-09-02.
  4. 1 2 F. Boudin; S. Allgeyer; P. Bernard; H. Hébert; M. Olcay; R. Madariaga; M. El-Madani; J.-P. Vilotte; S. Peyrat; A. Nercessian; B. Schurr; M.-F. Esnoult; G. Asch; I. Nunez; M. Kammenthaler (1 July 2013). "Analysis and modelling of tsunami-induced tilt for the 2007, M = 7.6, Tocopilla and the 2010, M = Maule earthquakes, Chile, from long-base tiltmeter and broadband seismometer records". Geophysical Journal International . 194 (1): 269–288. Bibcode:2013GeoJI.194..269B. doi: 10.1093/gji/ggt123 . hdl: 1885/77642 . ISSN   0956-540X.
  5. ↑ Griffiths, James (24 December 2018). "How Indonesia's tsunami warning system failed its citizens again". CNN. Archived from the original on 24 December 2018. Retrieved 24 December 2018.
  6. ↑ Annunziato, A, Husrin, S, Prasetya, G. (2019). ANAK KRAKATAU VOLCANO EMERGENCY TSUNAMI EARLY WARNING SYSTEM. Science of Tsunami hazards, pp. 68-95. link Archived 18 September 2021 at the Wayback Machine .
  7. ↑ "Reuters | Breaking International News & Views". Reuters. Archived from the original on 2011-02-24. Retrieved 2023-05-13.
  8. ↑ Martindale, Carol (24 January 2010). "Time right to test disaster awareness system". Nation Newspaper . Retrieved 24 January 2010. A TSUNAMI PROTOCOL to be tested here next month will help Barbadians be better prepared to deal with natural disasters such as earthquakes. ... Harewood said Barbados was nominated and accepted as the "pilot state" for the tsunami protocol which will be discussed from February 22 to 26. He said the objective of the Standard Operational Procedure and Communications Protocol, which has been being worked on for the last two years, is to provide more information on what must be done in the event of a tsunami, earthquake or any other major disaster. He noted that one of the things they would be doing was adopting a general public service announcement through the Government Information Service (GIS) to help increase awareness of tsunamis.
  9. ↑ "Japan Meteorological Agency – Flow of issuance of information about tsunami and earthquake". Archived from the original on 2 April 2016. Retrieved 15 April 2016.
  10. 1 2 "80 Seconds of Warning for Tokyo". MIT Technology Review. Archived from the original on 6 April 2020. Retrieved 15 April 2016.
  11. ↑ "Emergency Warning System Starting Shortly" (PDF). Archived from the original (PDF) on 31 August 2021. Retrieved 15 April 2016.
  12. ↑ "Leaflet "Start of New Tsunami Warning System Operation"" (PDF). Archived (PDF) from the original on 18 May 2016. Retrieved 15 April 2016.
  13. ↑ "Tsunami two years on: Japan finally gets warning system that would have saved hundreds of lives". 9 March 2013. Archived from the original on 23 April 2016. Retrieved 15 April 2016.
  14. ↑ "These 5 countries have advanced tsunami warning systems". 3 November 2021. Archived from the original on 7 September 2022. Retrieved 7 September 2022.
  15. ↑ "Indian Ocean tsunami of 2004 | Facts & Death Toll | Britannica". 17 November 2023. Archived from the original on 8 September 2022. Retrieved 7 September 2022.
  16. ↑ "ESSO-INCOIS-Indian National Centre for Ocean Information Services". incois.gov.in. Archived from the original on 2022-09-06. Retrieved 2022-09-07.
  17. ↑ "ESSO | Govt. of India". Archived from the original on 2022-09-07. Retrieved 2022-09-07.
  18. ↑ "ESSO | Govt. of India". Archived from the original on 2022-11-16. Retrieved 2022-09-07.
  19. ↑ "Indian Tsunami Buoy System Type - 1" (PDF). Archived from the original (PDF) on 2022-09-07.
  20. ↑ "Wadia Institute of Himalayan Technology". Archived from the original on 2022-09-07. Retrieved 2022-09-07.
  21. ↑ "ESSO-INCOIS-Indian National Centre for Ocean Information Services". Archived from the original on 2022-09-01. Retrieved 2022-09-07.
  22. ↑ "Oceansat-2 - ISRO". Archived from the original on 2019-12-11. Retrieved 2022-09-07.
  23. ↑ "Oceansat-2". The Times of India . 13 October 2013. Archived from the original on 5 October 2022. Retrieved 5 October 2022.
  24. ↑ UNESCO. "Subscribe to Receive International Advisories Through IOC Public Service". International Tsunami Information Center. Archived from the original on 6 December 2019. Retrieved 5 April 2019.
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