is a nationwide warning system in Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 launched in February 2007. It is designed to quickly inform the public of various threats. The system was developed in the hope that early warnings would speed up evacuation times and help coordinate emergency response.

The system

J-Alert is a satellite

Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 based system that allows authorities to quickly broadcast alerts to local media

Mass media

Mass media refers collectively to all media technologies which are intended to reach a large audience via mass communication. Broadcast media transmit their information electronically and comprise of television, film and radio, movies, CDs, DVDs and some other gadgets like cameras or video consoles...

 and to citizens directly via system of loudspeaker

Loudspeaker

A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...

s. According to Japanese officials it takes about 1 second to inform local officials, and between 4 and 20 seconds to relay the message to citizens.
All warnings are broadcast in five languages: English, Mandarin, Korean and Portuguese (Japan has a small Chinese, Korean and Brazilian population), including Japanese. The warnings were broadcast in these languages during the 11th March 2011 earthquake and tsunami

2011 Tōhoku earthquake and tsunami

The 2011 earthquake off the Pacific coast of Tohoku, also known as the 2011 Tohoku earthquake, or the Great East Japan Earthquake, was a magnitude 9.0 undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST on Friday, 11 March 2011, with the epicenter approximately east...

 .

Information able to be transmitted by this system

• Earthquake
  • Earthquake Early Warning
  • News flash of hypocenter
    Hypocenter
    The hypocenter refers to the site of an earthquake or a nuclear explosion...
    
    , magnitude, and precaution to tsunami
  • Information of hypocenter, magnitude, intensities of various cities, and presence of tsunami
  • Advisory information of Tokai earthquakes
    Tokai earthquakes
    The Tōkai earthquakes are major earthquakes that have occurred regularly with an interval of 100 to 150 years in the Tōkai region of Japan. The Tokai segment has been struck by earthquakes in 1498, 1605, 1707 and 1854...
    
    
  • Earthquake prediction information of Tokai earthquakes
  • Caution to Tokai earthquakes
• Tsunami
  Tsunami
  A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
  
  
• Volcano eruption
• Military threats
  • Korea
    North Korea
    The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...
    
    n ballistic missile
    Ballistic missile
    A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...
    
     launching
  • Air assault
  • Military attack to nuclear power plant
  • Large scale terrorism

Adoption rate

Many prefectures and urban area

Urban area

An urban area is characterized by higher population density and vast human features in comparison to areas surrounding it. Urban areas may be cities, towns or conurbations, but the term is not commonly extended to rural settlements such as villages and hamlets.Urban areas are created and further...

s have been slow to adopt the system. Upon its introduction the Japanese government hoped to have 80% of the country equipped with the J-Alert system by 2009. However, under current plans, by 2011 only 36% of the nation will have been covered. Cost has been a major factor. The initial installation estimate is estimated to be around 430 million yen, and the yearly maintenance is estimated to be around 10 million yen. Local governments have been hesitant to cut other services to implement the system.

External links

• http://www.terradaily.com/reports/Japan_Launches_Alert_System_For_Tsunamis_And_Missiles_999.html
• http://mdn.mainichi.jp/mdnnews/national/news/20081114p2a00m0na005000c.html