J-Alert ( ja, J－ALERT/Jアラート, J Arāto; full name ja, 全国瞬時警報システム, Zenkoku Shunji Keihō Shisutemu, National Early Warning System, label=none) is the

early warning system An early warning system is a warning system that can be implemented as a chain of information communication systems and comprises sensors, event detection and decision subsystems for early identification of hazards. They work together to forec ...

used in

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

. J-Alert was launched in February 2007. The system is designed to quickly inform the public of threats and emergencies such as

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s, 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.

System

J-Alert is a

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...

based system that allows authorities to quickly broadcast alerts to local

media Media may refer to: Communication * Media (communication), tools used to deliver information or data ** Advertising media, various media, content, buying and placement for advertising ** Broadcast media, communications delivered over mass e ...

and to

citizen Citizenship is a "relationship between an individual and a state to which the individual owes allegiance and in turn is entitled to its protection". Each state determines the conditions under which it will recognize persons as its citizens, and ...

s directly via a system of nationwide

loudspeaker A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or ...

television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising, ...

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a tr ...

email Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...

, and

cell broadcast Cell Broadcast (CB) is a method of sending messages to multiple mobile telephone users in a defined area at the same time. It is defined by the ETSI’s GSM committee and 3GPP and is part of the 2G, 3G, 4G LTE (telecommunication) and 5G st ...

s. According to Japanese officials, it takes about one second to inform local officials, and between four and twenty seconds to relay the message to citizens. An enhanced version of the J-Alert receivers were installed by the end of March 2019. The new models can automatically process the information within two seconds, compared to the older models that can take up to twenty seconds. All warnings, except for severe weather warnings, are broadcast in five languages: Japanese, English, Mandarin, Korean, and Portuguese (Japan has a small Chinese, Korean, and Brazilian population, as well as

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

, and other English-speaking populations). The warnings were broadcast in these languages during the

2011 Tōhoku earthquake and tsunami The occurred at 14:46 Japan Standard Time, JST (05:46 UTC) on 11 March. The Moment magnitude scale, magnitude 9.0–9.1 (M) Submarine earthquake, undersea megathrust earthquake had an epicenter in the Pacific Ocean, east of the Oshika Peni ...

. The severe weather warnings are only broadcast in Japanese. J-Alert broadcasts via both ground systems and the

Superbird-B3 Superbird-B3, known as Superbird-8 before launch, and DSN-1 (Kirameki-1) for its military payload, is a geostationary communications satellite operated by SKY Perfect JSAT Group and designed and manufactured by Mitsubishi Electric on the DS2000 ...

communication satellite. When there is a civil emergency such as a ballistic missile heading towards Japan, a special air raid siren sounds across loudspeakers and on TV and radio.

Information transmission capabilities

Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

** Earthquake Early Warning **Quick updates on

hypocenter In seismology, a hypocenter or hypocentre () is the point of origin of an earthquake or a subsurface nuclear explosion. A synonym is the focus of an earthquake. Earthquakes An earthquake's hypocenter is the position where the strain ener ...

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

, and precautions of possible tsunami **Information of

, intensities of various areas, and the presence of

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) 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 exp ...

**Earthquake prediction warning for the

Tōkai earthquakes The Tōkai earthquakes () are major earthquakes that have occurred regularly with a return period of 100 to 150 years in the Tōkai region of Japan. The Tōkai segment has been struck by earthquakes in 1498, 1605, 1707, 1854, and 1923. Given the h ...

**Earthquake prediction advisory information of the Tōkai earthquakes **Earthquake prediction information of the Tōkai earthquakes *

Tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) 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 exp ...

**Major

tsunami warning 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 communica ...

Tsunami warning 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 communica ...

Tsunami advisory A tsunami advisory means that a tsunami with potential for strong currents or waves dangerous to those in or very near the water is expected or occurring. There may be flooding of beach and harbor areas. Stay out of the water and away from beaches a ...

Volcano eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are ofte ...

**Emergency warning of volcanic eruption and the possibility of eruption **Warning of volcanic eruption and the possibility of eruption **Volcanic crater forecast *Severe weather **Emergency warnings for heavy rain, heavy snow, gale,

snowstorm A winter storm is an event in which wind coincides with varieties of precipitation that only occur at freezing temperatures, such as snow, mixed snow and rain, or freezing rain. In temperate continental climates, these storms are not necessar ...

waves Waves most often refers to: *Waves, oscillations accompanied by a transfer of energy that travel through space or mass. *Wind waves, surface waves that occur on the free surface of bodies of water. Waves may also refer to: Music *Waves (band) ...

, and storm surge **Warnings for heavy rain, heavy snow,

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).snowstorm A winter storm is an event in which wind coincides with varieties of precipitation that only occur at freezing temperatures, such as snow, mixed snow and rain, or freezing rain. In temperate continental climates, these storms are not necessar ...

, and storm surge **Weather advisory **Information of the risk of

landslides Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, ...

**Advisory information for

tornado A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, altho ...

**Information of violent heavy rain **Flood forecast *Special emergency threats **Information of

ballistic missile A ballistic missile is a type of missile that uses projectile motion to deliver warheads on a target. These weapons are guided only during relatively brief periods—most of the flight is unpowered. Short-range ballistic missiles stay within the ...

s **Information of airstrikes **Information of guerrilla and special forces attacks **Information of large-scale

terrorism Terrorism, in its broadest sense, is the use of criminal violence to provoke a state of terror or fear, mostly with the intention to achieve political or religious aims. The term is used in this regard primarily to refer to intentional violen ...

**Other information for civil and national defense

Adoption rate

Many prefectures and

urban area An urban area, built-up area or urban agglomeration is a human settlement with a high population density and infrastructure of built environment. Urban areas are created through urbanization and are categorized by urban morphology as cities ...

s were slow in adopting the system. Upon its introduction, the Japanese government hoped to have 80% of the country equipped with the J-Alert system by 2009. However, by 2011, only 36% of the nation had been covered. Cost had been a major factor; the initial installation is estimated to be around 430 million

yen The is the official currency of Japan. It is the third-most traded currency in the foreign exchange market, after the United States dollar (US$) and the euro. It is also widely used as a third reserve currency after the US dollar and the e ...

, and the yearly maintenance is estimated to be around 10 million

. By May 2013, 99.6% of municipalities nationwide were covered.

References

External links

J-Alert Overview

Fire and Disaster Management Agency The (FDMA) is an external agency attached to the Ministry of Internal Affairs and Communications in Japan. Background The Fire and Disaster Management Agency was established through article 3 paragraph 2 of the 1948 National Government Organizat ...

Ministry of Internal Affairs and Communications The is a cabinet-level ministry in the Government of Japan. Its English name was Ministry of Public Management, Home Affairs, Posts and Telecommunications (MPHPT) prior to 2004. It is housed in the 2nd Building of the Central Common Government Of ...

国民保護室・国民保護運用室

北朝鮮から発射された弾道ミサイルが日本に飛来する可能性がある場合における全国瞬時警報システム（Ｊアラート）による情報伝達について
Cabinet Secretariat Civil Protection
全国瞬時警報システム（J-ALERT）の整備

Guide on disaster prevention and mitigation effort during earthquakes and tsunamis

Japan Meteorological Agency The , abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation an ...

Protecting guide against Armed Attacks or Terrorism
Cabinet Secretariat Civil Protection
J-Alert message
relayed during the 2011 Tōhoku earthquake, warning of an imminent tsunami
全国瞬時警報システム実際の放送例 (J-Alert Demonstration)

YouTube YouTube is a global online video sharing and social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google, and is the second mo ...

{{Cell Broadcast System Emergency management in Japan Emergency population warning systems 2007 establishments in Japan 2007 introductions

System

Information transmission capabilities

Adoption rate

See also

References

External links