J-Alert (Zenkoku Shunji Keihō System)

J-Alert (全国瞬時警報システム Zenkoku Shunji Keihō System^?) is a nationwide warning system in Japan 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.

J-Alert is a satellite based system that allows authorities to quickly broadcast alerts to local media and to citizens directly via a system of loudspeakers.

J-Alert broadcasts via the Superbird-B2 communication satellite.

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). The warnings were broadcast in these languages during the 11th March 2011 earthquake and tsunami. The severe weather warnings are only broadcast in Japanese. 

Information able to be transmitted by this system

• Earthquake
  • Earthquake Early Warning
  • News flash of hypocenter, magnitude, and precaution to tsunami
  • Information of hypocenter, magnitude, intensities of various cities, and presence of tsunami
  • Advisory information of Tokai earthquakes
  • Earthquake prediction information of Tokai earthquakes
  • Caution to Tokai earthquakes
• Tsunami
• Volcano eruption
• Military threats
  • North Korean ballistic missile launching
  • Air assault
  • Military attack to nuclear power plant
  • Large scale terrorism