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March 30th, 2016
Technology • Finance

J-Alert: disaster warning technology in Japan

Japan is at high risk from natural disasters such as earthquakes and tsunamis, as well as from nuclear accidents and missile-based military offensives. In 2007, the government’s Fire and Disaster Management Agency launched J-Alert, a satellite-based system that enables local authorities to transmit warning messages directly to local media and citizens.

The initiative

In February 2007, Japan's Fire and Disaster Management Agency (FDMA) launched J-Alert, an early warning system that transmits instant emergency information about threats such as earthquakes, tsunamis and ballistic missile via sirens, so that people can respond immediately. “Authorities, who earlier relied on low-tech ways to spread alerts, will now be able to send instant warnings via sirens of imminent tsunamis, volcano eruptions or other disasters.” [1]

It was trialled in the western city of Kobe, which suffered a giant earthquake in 1995 that killed almost 6,500 people, and it started transmitting emergency earthquake information from all over Japan in October 2007.

“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. 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, except for severe weather warnings, are broadcast in five languages: Japanese, English, Mandarin, Korean and Portuguese.

Information is received by the FDMA control desk, warnings of armed attacks are received from the Cabinet Office, while observation data about extreme natural events comes from the Japan Meteorological Agency (JMA).

Its objectives are to:

  • Spread awareness of disaster updates to as many Japanese citizens as possible via loudspeaker, especially in the cases of earthquakes and missile launches.
  • Provide citizens with J-Alert reports, evacuation instructions or advice from local governments, flood alerts and radiation reports following a nuclear accident, as well as road conditions and the status of transportation systems.
  • Provide public information about shelters and other evacuation information after a certain period following a major disaster.

The challenge

According to Lloyd's City Risk Index, Tokyo is the second highest risk city in the world (after Taipei) with respect to natural disasters, due in no small part to Japan's high risk of earthquakes, typhoons, and tsunamis. “The geological formation, with plate boundaries of the Pacific plate, the Philippine Sea plate, the Eurasian plate, and the North American plate make Japan an earthquake-prone country. Also, because of its geographical, topographical, and meteorological conditions, it is subject to other frequent natural disasters such as typhoons, torrential rains, and heavy snow.”

In addition to these natural phenomena, Japan is conscious of the risks posed by nuclear accidents and the threat of military action, particularly of ballistic missiles fired by North Korea. Japan has been boosting its missile defences in cooperation with the United States since North Korea fired a long-range missile over Japan's main island into the Pacific Ocean in 1998.

The public impact

As of March 2010, 344 municipalities had introduced the J-Alert system via loudspeaker. The automatic activation system via radio broadcasting and community FM had been introduced to 282 municipalities.

“The warnings were broadcast in [five] languages during the 11 March 2011 earthquake and tsunami.” [2]

By May 2013, 99.6 percent of municipalities nationwide had “received the J-Alert receiver and 78 percent had the device that automatically sends out warning systems that relay emergency information messages”. [3]

Stakeholder engagement

The main stakeholders in J-Alert are the FDMA (which is part of the Ministry of Internal Affairs and Communications) and the Japanese government, principally through the Cabinet Office of Disaster Management.

There is strong engagement from other government agencies, such as  JMA, and from private sector corporations, such as JSAT (a Japanese satellite operator) and KDDI (a Japanese telecommunications company):

  • J-Alert broadcasts via JSAT's Superbird-B2 communication satellite.
  • “KDDI Corporation provides three services, ‘Disaster message board service', ‘Emergency email service' and ‘Disaster voice message' in the event that a disaster occurs to help confirm the safety of users.” [4]

Political commitment

The government has supported the technology and provided financial aid as necessary throughout the life of J-Alert:

  • “The central government plans to offer financial assistance for implementation of the system to prefectural and municipal governments, to run the system by 2013.” [5]
  • The 2014 fiscal year's budget also had JPY5 billion (US$62.6 million) for J-Alert, after a request was raised by the Internal Affairs and Communications Ministry.

Public confidence

The view of Japanese citizens about the handling of the 11 March 2011 Tōhoku earthquake and tsunami is ambivalent. “The Japanese public applauds how the country's Self Defense Force has responded to the March 11 earthquake and tsunami, but is highly critical of the how the government and the Tokyo Electric Power Company (TEPCO) have handled the multiple disasters. More than nine-in-ten (95%) describe the Self Defense Force's response positively. By contrast, only about 20% say the national government or Prime Minister Naoto Kan have responded well to the crisis. The harshest criticism is reserved for TEPCO, with just 10% saying the power company has done a good job responding to the earthquake and tsunami.” [6]

Therefore, this shows that, even though the public acknowledges the efforts and steps taken towards the earthquake disasters, they are still unsure overall.

Clarity of objectives

The government, at the inception of the project, aimed at making the residents aware of the disaster updates. However, there was no mechanism for a clearly defined measurements of the objectives.

Strength of evidence

There were several pilot programmes in place during the development of J-Alert:

  • J-Alert was first trialled in 2007. In the drill, disaster authorities relayed news of a medium-size quake to Kobe's Ichikawacho area.
  • On its second trial, radio speakers were installed in public places, to send out hypothetical alerts.
  • Four cities and 10 of Japan's 47 prefectures initially received the satellite alert system, which was then expanded to 80 percent of the country by March 2009.

Another pilot programme was begun in 2012, involving the governments of two prefectures: Shizuoka and Hyogo. Both local governments formed agreements with mobile phone carriers and TV stations which allowed them “to send mass messages to the cellphones of residents in affected areas or display alerts on TV screens when necessary”. [7]

There was a plan to roll out the piloted system throughout Japan. “Using these pilot examples the government is considering implementing a similar system for other prefectures so residents can directly receive J-Alerts and other emergency reports on their mobile devices or local cable TV and FM radio stations.” [8]


Japan has a long history of disaster management with multiple laws providing legislative support. Furthermore, the 2009 budget for J-Alert was JPY900 million, demonstrating that the project was financially feasible. However, some local administrations have been unwilling to make budget cuts elsewhere to fully implement the system.


There is a governing structure in place to monitor and measure disasters in Japan. The FDMA (Fire and Disaster Management Agency) and the Japanese government have divisions with an appropriate distribution of roles and responsibilities to each division:

  • The promotional body of J-Alert, FDMA, has a proper governing structure and management. The agency is led by the Commissioner of the FDMA, under whose direction the structure is segregated into various Divisions, such as the General Affairs Division and the Fire and Ambulance Service Division.
  • Additionally, the Japanese government has a Cabinet Office of Disaster Management, underneath which is a minister of state for disaster management. Reporting to the minister are the director for disaster response operations, the director for project promotion, etc.


The progress of J-Alert can be measured by its reach to Japanese citizens and by the levels of public awareness of its functions. By May 2013, 99.6% of municipalities nationwide received the J-Alert receiver.

There are agencies collecting data which then feeds into J-Alert. “JMA collects real-time data from seismometers, seismic intensity meters, gauge stations and other instruments to monitor earthquakes and tsunamis around the clock. When an earthquake causes serious damage, the Agency dispatches the JMA Mobile Observation Team (JMA-MOT) to assess the situation.” [9] However, how effective this system is and how extensively it is being used is not mentioned.


Multiple agencies coordinate the response to various disasters. Environmental hazards such as tsunamis and earthquakes are detected by the Japan Meteorological Agency (JMA) and military threats by the Cabinet Office. National and Local governments then coordinate the transmission of the alert via satellite and the broadcast of warnings to citizens via local radio stations.

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