The Emergency Broadcast is a means of public warning and public annoyance alike. Hearing an Emergency Broadcast warning of actual danger may lead to
. On the other hand, a test or a warning of something that doesn't affect you (e.g. a missing child warning, a flood when you're on high ground, a tsunami when you're 100 miles inland) may be a
. Another frequent frustration is when an actual alert has such horrible sound quality you can't understand what's being said. In many countries,
was the primary reason for the system's creation, and it eventually (and thankfully) ended up never being used for that purpose and being used for many others.
. Needless to say,
The first US Emergency Broadcast system was CONELRAD
(CONtrol of ELectronic RADiation), intended only to warn listeners/viewers of an impending atomic attack and to make it hard for Soviet bombers to find American cities by using radio direction finding; in the event of a CONELRAD Radio Alert, stations would all change to 640 or 1240 KHz (in the US AM band). It was eventually renamed the Emergency Broadcast System
when advances in communication and weather radar made it possible for state and local authorities to use it to disseminate information about local emergencies. Later, as alerts began to be disseminated through non-broadcast routes (cable and satellite TV, cellphones, weather radios), the system was again renamed, this time as the Emergency Alert System
, or EAS.
All TV and radio stations are required to test their EAS systems at least once a month, with weekly tests required for feeder stations. Of course these tests usually warn that there's no actual emergency going on first. This has resulted in the phrase "This is a test. This is only a test" and the old two-tone EBS attention beep becoming a part of popular culture
. The new EAS alerts may or may not include a two-tone attention beep but always include an encoded ASCII string, repeated three times, which sounds like an old-school modem and is called a "chirp" or "duck farts" in the business. The string contains specific information as to the type of alert (or test) and the location of the emergency. Some modern weather radios can be programmed to only activate the alarm for alerts that apply to where the radio's installed and only for hazards that would actually be of concern to the area. In some areas the EAS test is unannounced and contains only the three ASCII chirps.
The EAS is usually activated locally for tests and missing children/Amber Alerts. Tornado and severe thunderstorm/ flash flood
warnings are also common reasons for activations, occasionally leading to a Crowning Moment of Awesome
. Less commonly, fires
, chemical spills or other local disasters can result in an activation. State and especially national activations are usually reserved for nuclear attack
or any other apocalyptic-level
threat. Many times these alerts then redirect to an area's local NOAA Weather Radio station, where an automated voice reports the event's details.
In some areas prone to certain natural disasters (tornadoes, earthquakes, etc.) there is also a yearly disaster drill conducted with a state civil defense agency (in which a full "test warning" is issued, and which is meant to enable schools, hospitals, and even private homes to do a "dress rehearsal" practice for whatever disaster the "test warning" was for). Usually these are geared around various disaster awareness weeks (state tornado drills complete with EAS "test tornado warnings" tend to be around Severe Weather Awareness Week); these are also the last real relics of how Emergency Broadcast systems were tested in the CONELRAD era (full activations as part of state and national "duck and cover" civil defense drills on how to protect one's self against Atomic Hate
A national EAS test was performed on November 11, 2011—the first official "test activation" of a national level Emergency Broadcast since the CONELRAD era. It showed that nationally, the system needed a little work: Some cable providers switched to their EAS feed station (usually QVC or another Home Shopping channel) without showing the test, others didn't state that a test was happening, and Direct TV viewers were hearing Lady Gaga
instead of the test message.
One event where the EAS was not
activated was, oddly enough, September 11, 2001. Within minutes of the first plane hitting the World Trade Center, every radio/TV station and network capable of it (outside of kids' networks, who carried on as normal as a safe haven for children who might be traumatized by the news) had suspended its normal programming and was already broadcasting round-the-clock news on the attacks. The EAS administrators quickly realized that they had been outstripped by the news media and stepped out of the way.
On occasion, computer glitches or human error resulted in incidents where emergency alerts were issued accidentally. One egregious example occurred with the older Emergency Broadcast System in 1971, when a clerk intending to send out a routine test alert to all radio stations in the network accidentally loaded a Telex program tape that included the codeword "hatefulness," which was the code signal to the stations that a nuclear attack or other catastrophic emergency had been confirmed and that they were to immediately issue an on-air alert and suspend operations or remain on the air, but broadcasting only important news or survival information pertaining to the emergency. Even worse, a retraction message sent shortly after ALSO used "hatefulness" as the codeword, leading to more confusion. It wasn't until sometime after when a message using the correct codeword, "Impish," was issued that the matter was cleared up.
Only one province, Alberta, has an emergency warning system. The Alberta Emergency Public Warning System
was planned after an F5 tornado tore through Edmonton, but was only picked up by all broadcasters after a F3 tornado destroyed a campground at Pine Lake. The EPWS serves to advise the public of imminent threats such as severe summer weather (tornadoes, thunderstorms, and floods) and civil emergencies, and also broadcasts AMBER Alerts. It generally is not used to disseminate less emergent weather alerts such as snowfall or blizzard warnings, as those are considered relatively common events during most of the winter (and spring, and...).
In addition, Environment Canada runs Weatheradio Canada, which disseminates weather warnings, alerts, and tests on VHF radio.
United Kingdom: The Four-Minute Warning
, an emergency broadcast only
to be used in the case of Atomic Hate
. (This system was dismantled in 1992). Weather warnings and other emergency messages are done through news special reports.
Japan: The Emergency Warning System
is used primarily as a very short-fuse warning on earthquakes (e.g. 10 seconds or so between warning and quake at best) and to warn for imminent evacuation due to tsunamis
. The tone will almost immediately be followed up with a broadcast from the NHK in both Japanese and English audio or subtitles. The more bells/more urgent the tone, the more urgent or severe the threat is, and its use is reserved for imminent danger such as the aforementioned quake and tsunami warnings or an attack/incoming missile from North Korea
and breaking national tragedies such as the death of someone in the Imperial family, and some "types" of the tone are retired. (For example, the tone that was used to indicate the start of WWII has yet to be used again)note
Also, the Japanese test signal is not entirely standardized across broadcasting stations (even stations within a given city like will differ; examples abound on YouTube
) except for the emergency chime, a video/audio description of when a real broadcast would be activated, an emergency tone, and a notification in Japanese that the audible "piro-piro-piro" tone (the data burst, not the bells mentioned above) is only audible on analog TVs, with an additional device required after the digital transition due to it being a data signal to digital TVs.
Much as is the case with the "required weekly test" and "required monthly test" of the Emergency Alert System in the US, the Emergency Warning System is tested regularly in Japan (at least on NHK affiliates) with the "piro-piro-piro" digital header and instructions on what to do in the event of an actual earthquake or tsunami warning (and a reassurance that "This Is Only A Test").
Australia: The Standard Emergency Warning Signal
, used primarily in Queensland to warn of cyclones, but now being expanded for bushfires and terror threats in the rest of the country. Possibly, along with Japan's EWS and Alberta's EPWS, one of the few Emergency Broadcast systems to originally be developed specifically for a weather/geological hazard rather than Atomic Hate
Alarm sirens are tested the first Wednesday each month, at noon. They are (sometimes) accompanied by voice messages announcing that it's just a test, but especially if you are in a building the only thing you hear is the sirens' wailing.
Austria has several kinds of alarm sirens that are broadcasted mostly from the firefighter stations.
Siren test (every Saturday at noon): 1x 15 seconds steady
Fire alarm: 3x 15 seconds steady
Warning: 3 minutes steady
Alarm: 1 minute wailing
All-clear: 1 minute steady
All sirens are tested on one Saturday in the year instead of the noon test.
Around the fifteenth of every month (usually) at 2pm, civil defense drills are conducted. Sirens go off and all road activity is stopped for fifteen minutes. Pedestrians are encouraged to get off the pavement and take shelter. Radio stations (but not TV) interrupt their broadcasts with the sirens at 2pm and tell people where to go and what to do in case of emergency (usually assumed to be an attack from North Korea
). At 2:15pm an all clear siren sounds and normal activity resumes. Sometimes (during increased tension with North Korea) civil defense drills will be held more frequently.
Until fairly recently—and uniquely for an Emergency Broadcast system—civil defense alerts were also broadcasted on the (American operated) Armed Forces Radio and Television Service; this was because (among other things) American instructions during an attack warning in South Korea explicitly included instructions on evacuating the country.
An old system of power-independent wire radio ("radiotochka") still exists for this exact purpose, for performing emergency broadcasts even during blackouts.
The Tseva Adom
or "Red Colour" system is an emergency system (including not only emergency broadcasts but sirens and announcements on public speaker systems and even alerts sent to smart phones) used primarily in communities surrounding the Gaza Strip to warn of incoming missile attacks. In fact, the civil defense system lent its name to a documentary about children
living in areas with frequent "Tseva Adom" alerts—the "Tseva Adom" system is in fact probably the most frequently used attack warning
system in the world, with multiple alerts a day not being uncommon (even before the formal outbreak of war between Israel and the Gaza Strip)—a "Tseva Adom" alert is sometimes colloquially known as the "fifteen second warning", as that is usually about how much time one has to get to the bomb shelter.
As of the outbreak of hostilities between Israel and the Gaza Strip on 16 November 2012, "Tseva Adom" has in fact become the generic term for an attack warning in Israel and the "Tseva Adom" system has in fact been officially extended nationwide (example here
for a "Tseva Adom" warning outside the Gaza Strip border territories and here
for an example of a commercial interrupted by a "Tseva Adom" alert); "Tseva Adom" warnings are also announced on hospital and other major building loudspeaker systems.
As a part of the national rollout of the "Tseva Adom" system, the Israel Broadcast Authority established 531 KHz (in the Israeli/Middle Eastern AM band) as the national channel for announcing of Tseva Adom alerts and civil defense alerts; per this link
, the station—normally the main channel of Israel's national broadcast company—goes silent during the Jewish Sabbath (Friday evening through Saturday evening) with the exception of announcing Tseva Adom warnings so that observant Orthodox and Hasidic Jews are not forced to turn on an emergency radio or tune to a frequency to get civil defense alerts (which would normally be a violation of religious law).
A general system of sirens and radio and television emergency broadcasts existed in the rest of Israel (before the national rollout of the "Tseva Adom" system) that was similar to the system presently used in South Korea; this has had "live use" including instructions for people to don gas masks and to retreat to safe rooms during the first Gulf War (due to concerns that Iraqi SCUD missiles could have chemical warheads).
Finland has extensive air raid siren network across the country (courtesy of being target for both NATO and Warsaw pact warheads during Cold War) that has been tested since 2009 on first working Monday of the month at 12 o'clock, with televised test 40 minutes earlier than that. Television system has been used to warn of local hazards like toxic smoke from fires or escaped criminals.
Of the natural disaster variety. The Sistema de Alerta Sísmica
(Seismic Alert System) consisting of a network of seismic detectors deployed near the Guerrero and Oaxaca coastline will send an early warning upon detecting a strong earthquake. Recipients in Mexico City will theoretically have 50 seconds to act upon receiving the alert. While TV and Radio do sound the alert, there isn't a public megaphone system to sound the alarm itself in the city, though anyone using a radio reciever tuned to the SAS frequency will get the signal, as well as some schools and government buildings which are directly connected to the Early Warning System.