Earthquake Early Warning (Japan)
Encyclopedia
The is a warning issued just after an earthquake in Japan is detected. The warnings are issued mainly by the Japan Meteorological Agency
Japan Meteorological Agency
The or JMA, is the Japanese government's weather service. Charged with gathering and reporting weather data and forecasts in Japan, it is a semi-autonomous part of the Ministry of Land, Infrastructure and Transport...

 (JMA), and they issue tips on how to react to the warnings.

Introduction

The JMA has two Earthquake Early Warning schemes; one is for advanced users, another for the general public. Upon P-wave
P-wave
P-waves are a type of elastic wave, also called seismic waves, that can travel through gases , solids and liquids, including the Earth. P-waves are produced by earthquakes and recorded by seismographs...

 detected by any two or more out of 4,235 seismometer
Seismometer
Seismometers are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources...

s installed throughout Japan (as of 1 April 2010), JMA
Japan Meteorological Agency
The or JMA, is the Japanese government's weather service. Charged with gathering and reporting weather data and forecasts in Japan, it is a semi-autonomous part of the Ministry of Land, Infrastructure and Transport...

 automatically analyzes and predicts the rough area of epicenter
Epicenter
The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...

 and warns people in prefectures
Prefectures of Japan
The prefectures of Japan are the country's 47 subnational jurisdictions: one "metropolis" , Tokyo; one "circuit" , Hokkaidō; two urban prefectures , Osaka and Kyoto; and 43 other prefectures . In Japanese, they are commonly referred to as...

 through TV and radio if strong shaking is expected.

Earthquake Early Warning (alert)(緊急地震速報(警報)) is issued to general public when Japan seismic scale 5-lower or more
Japan Meteorological Agency seismic intensity scale
The Japan Meteorological Agency seismic intensity scale is a seismic scale used in Japan and Taiwan to measure the intensity of earthquakes. It is measured in units of...

 is expected. Earthquake Early Warning (forecast)(緊急地震速報(予報)) is issued to advanced user when Japan seismic scale 3 or more
Japan Meteorological Agency seismic intensity scale
The Japan Meteorological Agency seismic intensity scale is a seismic scale used in Japan and Taiwan to measure the intensity of earthquakes. It is measured in units of...

, or magnitude
Richter magnitude scale
The expression Richter magnitude scale refers to a number of ways to assign a single number to quantify the energy contained in an earthquake....

 3.5 or more is expected, or 100 or more gal
Gal (unit)
The gal, sometimes called galileo, is a unit of acceleration used extensively in the science of gravimetry. The gal is defined as 1 centimeter per second squared ....

 is detected in amplitude
Amplitude
Amplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation...

 of P-wave
P-wave
P-waves are a type of elastic wave, also called seismic waves, that can travel through gases , solids and liquids, including the Earth. P-waves are produced by earthquakes and recorded by seismographs...

 or S-wave
S-wave
A type of seismic wave, the S-wave, secondary wave, or shear wave is one of the two main types of elastic body waves, so named because they move through the body of an object, unlike surface waves....

.

The timing of a warning depends on conditions when a warning can be issued and received. After receiving a warning, a person may have a few seconds at longest to take action, but if the epicenter is very close there may be cases in which strong tremors come ahead of any warning.

The Earthquake Early Warning is set up to enable people to mitigate damage from an earthquake: people may protect themselves at home, at the office, and near cliffs. Railway workers may use this warning to slow down trains, and factory workers may use it to stop assembly lines prior to an earthquake.

Following the 2011 Tōhoku 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...

, the early warning system, along with Japan's tsunami warning system
Tsunami warning system
A Tsunami warning system is used to detect tsunamis in advance and issue warnings to prevent loss of life and damage. It consists of two equally important components: a network of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to permit evacuation of coastal...

, was considered effective by Indian scientist Dr. Shailesh Nayak, who helped develop India's warning system, though the tsunami nonetheless killed over 10,000 people.

In April 2011, the Chilean Subsecretary of Telecommunications will disclose to implement similar Earthquake Early Warning system utilized in Japan through ISDB-T.

NHK

On NHK
NHK
NHK is Japan's national public broadcasting organization. NHK, which has always identified itself to its audiences by the English pronunciation of its initials, is a publicly owned corporation funded by viewers' payments of a television license fee....

 television channels (Analog TV and ISDB-T), an alert consists of a message window that flashes on the screen showing the earthquake epicenter and the areas most vulnerable to strong tremors. At the same time, two sets of chimes sound, after which a voice announces in Japanese:
The alert also informs viewers whether or not there is a risk of a landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...

 or 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...

 caused by the quake in the affected area. If tsunami warnings are issued, the Emergency Warning Broadcast
Emergency Alert System
The Emergency Alert System is a national warning system in the United States put into place on January 1, 1997, when it superseded the Emergency Broadcast System , which itself had superseded the CONELRAD System...

 system breaks into the signal and automatically turns on all radios and televisions in the warned areas tuned to NHK at the time the system is activated, so that the warnings are received properly. All warnings are broadcast in five languages: English, Mandarin, Korean and Portuguese (Japan has small populations who speak these languages), as well as Japanese. The warnings were broadcast in these languages during the 2011 Tōhoku 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...

.

Mobile phone networks

Japan's three major mobile phone carriers, NTT docomo
NTT DoCoMo
is the predominant mobile phone operator in Japan. The name is officially an abbreviation of the phrase, "do communications over the mobile network", and is also from a compound word dokomo, meaning "everywhere" in Japanese. Docomo provides phone, video phone , i-mode , and mail services...

, au (KDDI
KDDI
is a Japanese telecommunications operator formed in October 2000 through the merger of DDI Corp., KDD Corp., and IDO Corp. It has its headquarters in the Garden Air Tower in Iidabashi, Chiyoda, Tokyo....

 and Okinawa Cellular) and SoftBank Mobile, have developed the simultaneous broadcast systems conforming Cell Broadcast
Cell Broadcast
Cell Broadcast messaging is a mobile technology feature defined by the ETSI’s GSM committee and is part of the GSM standard. It is also known as Short message service-Cell Broadcast ....

 to receive EEW and provided phones with this service since 2007.

It is mandatory for 3G cellular phones that were put on the market after 2007 to receive this service, though overseas manufacturers (Nokia, Apple, HTC, LG, Samsung, etc.) are not supported. In August 2011, Apple announced that its iOS 5 iPhone platform will support early warning notification.

NTT docomo

EEW is enabled by default on all models of the released on November 26, 2007, some FOMA High-Speed models of the released in February 2008 and all the newer models. NTT docomo started the free EEW service on December 10.

au

EEW is enabled on all models newer than 2008 Spring models released on January 9, 2008, including W61CA, W61H, W61K, W61SA, W61SH, W62SA and a few smartphone
Smartphone
A smartphone is a high-end mobile phone built on a mobile computing platform, with more advanced computing ability and connectivity than a contemporary feature phone. The first smartphones were devices that mainly combined the functions of a personal digital assistant and a mobile phone or camera...

 models, such as IS02 (TSI01). KDDI and Okinawa Cellular started EEW broadcast via au's Short Message Service
Short message service
Short Message Service is a text messaging service component of phone, web, or mobile communication systems, using standardized communications protocols that allow the exchange of short text messages between fixed line or mobile phone devices...

 called for free on March 25, 2008.

SoftBank Mobile

On May 30, 2007, SoftBank
SoftBank
is a Japanese telecommunications and internet corporation, with operations in broadband, fixed-line telecommunications, e-Commerce, Internet, broadmedia, technology services, finance, media and marketing, and other businesses....

 announced development of a EEW broadcast system similar to those of NTT docomo and au. Deployment of this system was originally planned in fiscal 2008 but postponed two years. On August 25, 2010, EEW service started in all areas of the Kansai region, Tokai region
Tokai region
The is a sub-region of the Chūbu region in Japan that runs along the Pacific Ocean. The name means "East sea" and comes from the Tōkaidō, one of the Edo Five Routes...

, Tohoku region
Tohoku region
The is a geographical area of Japan. The region occupies the northeastern portion of Honshu, the largest island of Japan. The region consists of six prefectures : Akita, Aomori, Fukushima, Iwate, Miyagi and Yamagata....

 (seven prefectures), Chugoku region
Chugoku region
The , also known as the , is the westernmost region of Honshū, the largest island of Japan. It consists of the prefectures of Hiroshima, Okayama, Shimane, Tottori and Yamaguchi. It has a population of about 7.8 million.- History :...

, and Shikoku region as well as limited areas of the Kanto region
Kanto region
The is a geographical area of Honshu, the largest island of Japan. The region includes the Greater Tokyo Area and encompasses seven prefectures: Gunma, Tochigi, Ibaraki, Saitama, Tokyo, Chiba, and Kanagawa. Within its boundaries, slightly more than 40 percent of the land area is the Kantō Plain....

. The EEW broadcast network covers the whole country since December 7, 2010. As of March 2011, :ja:SoftBank 831N is the only model that supports EEW, although more models are expected to support EEW after summer 2010.

Other

RC Solution Co. developed an iPhone
IPhone
The iPhone is a line of Internet and multimedia-enabled smartphones marketed by Apple Inc. The first iPhone was unveiled by Steve Jobs, then CEO of Apple, on January 9, 2007, and released on June 29, 2007...

 application named "Yurekuru Call for iPhone" to receive EEW, which is distributed on App Store for free. Notification of an EEW might be delayed or blocked if communication lines are congested. The Japan-localized version of iOS 5 for iPhone has built-in EEW functionality.

Radio receivers

The specific and common chime
Chime (bell instrument)
A carillon-like instrument with fewer than 23 bells is called a chime.American chimes usually have one to one and a half diatonic octaves. Many chimes play an automated piece of music. Prior to 1900, chime bells typically lacked dynamic variation and the inner tuning required to permit the use of...

 tone from FM
Frequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

 stations is automatically detected internally and turns on the radio, if in sleep mode
Sleep mode
Sleep mode refers to a low power mode for electronic devices such as computers, televisions, and remote controlled devices. These modes save significant electrical consumption compared to leaving a device fully on and idle, but allow the user to avoid having to reset programming codes or wait for a...

, and sounds a chime tone and EEW message to people for careful attention or awake, even in bed, by loud sound before shaking occurs by S-wave
Seismic wave
Seismic waves are waves of energy that travel through the earth, and are a result of an earthquake, explosion, or a volcano that imparts low-frequency acoustic energy. Many other natural and anthropogenic sources create low amplitude waves commonly referred to as ambient vibrations. Seismic waves...

. Soon after S-wave analyzed, the detailed information of earthquake such as seismic scale
Seismic scale
A seismic scale is used to calculate and compare the severity of earthquakes....

 and associated cities and towns is announced.
  • Iris Ohyama
    Iris Ohyama
    is a Japanese consumer plastic manufacturer based in Aoba-ku, Sendai, Miyagi Prefecture. It is the leading storage organization manufacturer in Japan. The company designs and manufactures products aimed at the housewares, garden accessories, office products and pet supplies markets.Iris Ohyama...

     EQA-001
  • Iris Ohyama EQA-101
  • Uniden
    Uniden
    is a Japanese company in the wireless communication industry.-History:Uniden was established on February 7, 1966 by its founder Hideo Fujimoto...

     EWR200 supports EEW and the recognizes voices on NHK Radio 1
    NHK Radio 1
    NHK Radio 1 is a Japanese radio station operated by the public broadcaster, NHK. Its programming output, which consists of news, current affairs, and information programming is broadly similar to BBC Radio 4, CBC Radio One, and Deutschlandfunk. NHK Radio 1 is available mainly on AM....

    .


These receivers utilize EEW broadcast from radio stations and are free of specific information fees or connection fees. EEW radio waves can be received even in areas where no broadband Internet access
Broadband Internet access
Broadband Internet access, often shortened to just "broadband", is a high data rate, low-latency connection to the Internet— typically contrasted with dial-up access using a 56 kbit/s modem or satellite Internet with inherently high latency....

 is available. The quality of service, rapidity, and service area may vary from station to station.

Cable television

Japanese cable TV stations offer affordable EEW services. For example, (JCN) rents a receiver that receives EEW for advanced users and notifies the user of the estimated Shindo scale
Japan Meteorological Agency seismic intensity scale
The Japan Meteorological Agency seismic intensity scale is a seismic scale used in Japan and Taiwan to measure the intensity of earthquakes. It is measured in units of...

 and the remaining time (0 to 5 seconds). Some cable TV stations also broadcast EEW on community radio
Community radio
Community radio is a type of radio service, that offers a third model of radio broadcasting beyond commercial broadcasting and public broadcasting. Community stations can serve geographic communities and communities of interest...

 FM and provide equipment to prefectural and municipal facilities for free

The Internet

, a weather information company, started a paid service to broadcast EEW for advanced users, The Last 10-Second, targeted at individuals and businesses on October 15, 2007. This service requires a computer running Windows 2000
Windows 2000
Windows 2000 is a line of operating systems produced by Microsoft for use on personal computers, business desktops, laptops, and servers. Windows 2000 was released to manufacturing on 15 December 1999 and launched to retail on 17 February 2000. It is the successor to Windows NT 4.0, and is the...

 or later with an always-on connection to the Internet and offers an affordable alternative to a costly communication terminal used exclusively for EEW. The EEW client application installed on the computer can be configured to receive information on all earthquakes with a JMA magnitude of 3.5 or higher or with a seismic intensity of 3 or higher. Newer versions of the program allow for the announcement of lower-intensity earthquakes. When an EEW warning is issued, the program will announce the approximate location of the epicenter, the expected JMA seismic intensity and display a countdown of when major shaking is to be expected.

After the 2011 Tōhoku earthquake, a similar Windows program was made available for free by the Strategy Corporation (:ja:ストラテジー株式会社) called SignalNow Express.

On July 7, 2008, , a disaster prevention technology company of the Railway Technical Research Institute
Railway Technical Research Institute
, or , is the technical research company under the Japan Railways group of companies.- Overview :RTRI was established in its current form in 1986 just before Japanese National Railways was privatised and split into separate JR group companies. RTRI conducts research about everything related to...

 Group, released a client application, EQMessenger, to receive ANET Alert, which ciphers and broadcasts EEW information on the epicenter, the estimated seismic intensity at the user's location, and the remaining time before the arrival of the S-wave. When the estimated seismic intensity exceeds the preset level, EQMessenger can sound a warning and display the epicenter, the intensity estimation point, and the arrival of the tremor on a pop-up map.

Identification of EEW capable devices

The current Earthquake Early Warning logo used by the Japan Meteorological Agency uses a yellow catfish known as a Namazu (鯰). Many earthquake preparedness activities in Japan use the catfish as a mascot, as Japanese lore suggested that earthquakes were caused by a giant catfish making tremors, or that catfish were seen to predict earthquakes.

See also

  • Earthquake warning system
    Earthquake warning system
    An earthquake warning system is a system of accelerometers, communication, computers, and alarms that is devised for regional notification of a substantial earthquake while it is in progress...

  • Earthquake prediction
    Earthquake prediction
    An earthquake prediction is a prediction that an earthquake of a specific magnitude will occur in a particular place at a particular time . Despite considerable research efforts by seismologists, scientifically reproducible predictions cannot yet be made to a specific day or month...

  • J-Alert
    J-Alert
    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....

  • Cell Broadcast
    Cell Broadcast
    Cell Broadcast messaging is a mobile technology feature defined by the ETSI’s GSM committee and is part of the GSM standard. It is also known as Short message service-Cell Broadcast ....


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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