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.
A warning system for the Indian Ocean was prompted by the 2004 Indian Ocean earthquake 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-based Pacific Tsunami Warning Center, which operates in the Pacific Ocean.
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.
The Indian Ocean Tsunami Warning System was agreed to in a United Nations conference held in January 2005 in Kobe, Japan as an initial step towards an International Early Warning Programme. 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. 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. [1] 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. [2]
Sensor data is processed by the U.S. Pacific Tsunami Warning Center in Hawaii and the Japan Meteorological Agency, 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. [3]
The system was not yet operational during the 2006 Pangandaran earthquake and tsunami. 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 7.39 m (24.2 ft) 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. [4] 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. [3]
Of the 28 countries that ring the Indian Ocean, Australia, Indonesia and India are now responsible for spearheading tsunami warnings in the area. [5]
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. [6]
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 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.
On 26 December 2004, at 07:58:53 local time (UTC+7), a major earthquake with a magnitude of 9.2–9.3 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.
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 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 is indicative of an earthquake's tsunami potential.
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.
The 2005 Nias–Simeulue earthquake occurred on 28 March off the west coast of northern Sumatra, Indonesia in the subduction zone of the Sunda megathrust. At least 915 people were killed, mostly on the island of Nias. It was the third most powerful earthquake since 1965 in Indonesia with a magnitude of 8.6 that caused a relatively small tsunami. Damage ranged from hundreds of buildings being destroyed in Nias to widespread power outages throughout the island of Sumatra. Following the mainshock, eight major aftershocks occurred ranging from 5.5 to 6.0 magnitudes.
The Central Weather Administration is the government meteorological research and forecasting institution of 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.
An earthquake occurred on July 17, 2006, at 15:19:27 local time along a subduction zone off the coast of west and central Java, a large and densely populated island in the Indonesian archipelago. The shock had a moment magnitude of 7.7 and a maximum perceived intensity of IV (Light) in Jakarta, the capital and largest city of Indonesia. There were no direct effects of the earthquake's shaking due to its low intensity, and the large loss of life from the event was due to the resulting tsunami, which inundated a 300 km (190 mi) portion of the Java coast that had been unaffected by the earlier 2004 Indian Ocean earthquake and tsunami that was off the coast of Sumatra. The July 2006 earthquake was also centered in the Indian Ocean, 180 kilometers (110 mi) from the coast of Java, and had a duration of more than three minutes.
An earthquake warning system or earthquake alarm system is a system of accelerometers, seismometers, communication, computers, and alarms that is devised for rapidly notifying adjoining regions of a substantial earthquake once one begins. This is not the same as earthquake prediction, which is currently not capable of producing decisive event warnings.
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 8.4, which makes it in the top 20 of the largest earthquakes ever recorded on a seismograph.
J-Alert is the early warning system used in Japan. J-Alert was launched in February 2007. The system is designed to quickly inform the public of threats and emergencies such as earthquakes, severe weather, and other dangers. The system was developed in the hope that early warnings would speed up evacuation times and help coordinate emergency response.
A teletsunami is a tsunami that originates from a distant source, defined as more than 1,000 km (620 mi) away or three hours' travel from the area of interest, sometimes travelling across an ocean. All teletsunamis have been generated by major earthquakes such as the 1755 Lisbon earthquake, 1960 Valdivia earthquake, 1964 Alaska earthquake, 2004 Indian Ocean earthquake, 2011 Tohoku earthquake, and the 2021 South Sandwich Islands earthquakes.
The 2010 Chile earthquake occurred off the coast of central Chile on Saturday, 27 February at 03:34:12 local time, having a magnitude of 8.8 on the moment magnitude scale, with intense shaking lasting for about three minutes. It was felt strongly in six Chilean regions that together make up about 80 percent of the country's population. According to the United States Geological Survey (USGS) the cities experiencing the strongest shaking—VIII (Severe) on the Mercalli intensity scale (MM)—were Concepción, Arauco, and Coronel. According to Chile's Seismological Service, Concepción experienced the strongest shaking at MM IX (Violent). The earthquake was felt in the capital Santiago at MM VII or MM VIII. Tremors were felt in many Argentine cities, including Buenos Aires, Córdoba, Mendoza, and La Rioja. Tremors were felt as far north as the city of Ica in southern Peru. It is the largest earthquake to hit Chile since the 1960 Valdivia earthquake.
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.
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.
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.
An earthquake off the coast of Samar occurred on August 31, 2012, at 20:47 local time in the Philippines. The populated islands of Visayas were struck by an earthquake of magnitude Mw 7.6. The earthquake occurred at a depth of 45 km. A tsunami warning was announced within the Pacific area and was lifted after two hours. The Philippine archipelago is located in the Pacific Ring of Fire, where earthquakes and volcanic activity are common.
The 2012 Haida Gwaii earthquake occurred just after 8:04 p.m. PDT on October 27. The shock had a moment magnitude of 7.8 and a maximum Mercalli Intensity of V (Moderate). The earthquake's epicentre was on Moresby Island of the Haida Gwaii archipelago. This was the second largest Canadian earthquake ever recorded by a seismometer, after the 1949 Queen Charlotte Islands earthquake, about 135 kilometres (84 mi) away. One person died due to a car crash related to the tsunami in Oahu, Hawaii.
On January 23, 2018, at 00:31 AKST, an earthquake occurred in the Gulf of Alaska near Kodiak Island. The earthquake, measured at 7.9 on the Mw scale, was approximately 280 kilometers (170 mi) southeast of Kodiak and happened at a depth of 25 kilometers (16 mi).
Building Back Better, or more frequently termed Build Back Better (BBB), is a strategy aimed at reducing the risk to the people of nations and communities in the wake of future disasters and shocks. It is a conceptual strategy that has continued to evolve since its origination in May 2005. However, what continues is the overall goal of enabling countries and communities to be stronger and more resilient following a disaster by reducing vulnerability to future disasters. Building resilience entails addressing physical, social, environmental, and economic vulnerabilities and shocks.