The Indian Ocean Tsunami Warning System, abbreviated as IOTWS, was set up to provide warning to inhabitants of nations bordering the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

of approaching

tsunami A tsunami ( ; from , ) 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 underwater explosions (including detonations, ...

s. The tsunami warning system has been in use since the mid-2000s.

Background

A warning system for the Indian Ocean was prompted by the

2004 Indian Ocean earthquake On 26 December 2004, at 07:58:53 local time (UTC+07:00, UTC+7), a major earthquake with a magnitude of 9.2–9.3 struck with an epicenter, epicentre off the west coast of Aceh in northern Sumatra, Indonesia. The Submarine earthquake, undersea ...

and resulting tsunami, which left approximately 250,000 people dead or missing. Many analysts claimed that the disaster would have been mitigated if there had been an effective warning system in place, citing the well-established

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

-based Pacific Tsunami Warning Center, which operates in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. People in some areas would have had more than adequate time to seek safety if they were aware of the impending catastrophe. The only way to effectively mitigate the impact of a tsunami is through an early warning system. Other methods such as sea walls only work for a percentage of waves, but a warning system is effective for all waves originating outside a minimum distance from the coastline.

Construction

The Indian Ocean Tsunami Warning System was agreed to in a

United Nations The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...

conference held in January 2005 in

Kobe Kobe ( ; , ), officially , is the capital city of Hyōgo Prefecture, Japan. With a population of around 1.5 million, Kobe is Japan's List of Japanese cities by population, seventh-largest city and the third-largest port city after Port of Toky ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

as an initial step towards an

International Early Warning Programme The International Early Warning Program (IEWP), was first proposed at the Second International Early Warning Conference (EWCII) in 2003 in Bonn, Germany. It developed increasing importance in the wake of the 2004 Indian Ocean tsunami, which claimed ...

. Nanometrlolics (Ottawa, Canada) and RESULTS Marine Private Limited, India, delivered and successfully installed 17 Seismic VSAT stations with two Central Recording Station to provide the seismic event alert to the scientists through SMS and e-mail automatically within two minutes. The system became active in late June 2006 following the leadership of

UNESCO The United Nations Educational, Scientific and Cultural Organization (UNESCO ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) with the aim of promoting world peace and International secur ...

. It consists of 25 seismographic stations relaying information to 26 national tsunami information centers, as well as six Deep-ocean Assessment and Reporting of Tsunami (DART) buoys. However, UNESCO warned that further coordination between governments and methods of relaying information from the centers to the civilians at risk are required to make the system effective. Sensor data is processed by the U.S. Pacific Tsunami Warning Center in Hawaii and the

Japan Meteorological Agency The Japan Meteorological Agency (JMA; ''気象庁, Kishō-chō'') is a division of the Ministry of Land, Infrastructure, Transport and Tourism dedicated to the Scientific, scientific observation and research of natural phenomena. Headquartered ...

, and alerts are forwarded to threatened countries and also made available to the general public. National governments warn citizens through a variety of means, including Cell Broadcast messages, SMS messages, radio and television broadcasts, sirens from dedicated platforms and mosque loudspeakers, and police vehicles with loudspeakers.

Performance during emergencies

The system was not yet operational during the

2006 Pangandaran earthquake and tsunami An earthquake occurred on July 17, 2006, at along a subduction zone off the coast of West Java, west and central Java, a large and densely populated island in the Indonesian archipelago. The shock had a Moment magnitude scale, moment magnitude ...

. The Indonesian government did receive tsunami warnings from the warning centers but did not have a system to relay the alert to its citizens. At least 23,000 people evacuated the coast after the quake, either fearing a tsunami or because their homes had been destroyed. Waves as high as still resulted in about 700 fatalities and 9,000 injuries. In the 2012 Indian Ocean sequence, the system alerted the Indian islands on Andaman and Nicobar within eight minutes. Some tsunami warning sirens in Aceh were delayed by about 20 minutes due to failure of the electrical grid caused by the proximity of the earthquake, and evacuation routes in Banda Aceh were jammed with traffic. Of the 28 countries that ring the Indian Ocean, Australia, Indonesia and India are now responsible for spearheading tsunami warnings in the area.Penberthy, Natsum
On this day in history: 2004 Boxing Day tsunami
australiangeographic.com, 26 December 2014 The system had no means to predict tsunamis from volcanic eruptions. After the 2018 Sunda Strait tsunami, the Indonesian government installed sea level sensors to fill this gap.Annunziato, A, Husrin, S, Prasetya, G. (2019). ANAK KRAKATAU VOLCANO EMERGENCY TSUNAMI EARLY WARNING SYSTEM. ''Science of Tsunami hazards'', pp. 68-95
link
.

References

External links

{{portal, Oceans, Tsunamis
German Indonesian Tsunami Early Warning System

Envirtech Tsunami Warning System, based on real time seafloor observatories measuring seismic waves and sea levels
Emergency management in Asia Warning systems Tsunami Indian Ocean