Editing Emergency Alert System (section)

{{short description|Method of emergency broadcasting in the United States}}
{{Distinguish|Wireless Emergency Alerts|Emergency Warning Broadcast system|Emergency Warning System|Emergency Broadcast System}}
{{Use mdy dates|date=December 2023}}
{{Infobox broadcasting network|name=Emergency Alert System|network_type=[[Emergency population warning|Emergency warning system]]|country=United States|broadcast_area=Varies; nationwide for national activation, limited to 31 locations at a time for regional activation, including [[County (United States)|counties]], [[List of parishes in Louisiana|parishes]], [[List of boroughs and census areas in Alaska|boroughs]] (and any other [[County equivalents|equivalents]]), entire [[U.S. state|states]], [[Washington, D.C.]], and [[Territories of the United States|territories]]|launched={{start date and age|January 1, 1997}}|logo=EAS new.svg|logo_size=190px|replaced=[[Emergency Broadcast System]], [[Local Access Alert]]|tvstations=All broadcast television stations and cable systems|radiostations=77 designated Primary Entry Point (PEP) stations. All commercial radio stations}}

The '''Emergency Alert System''' ('''EAS''') is a [[Emergency population warning|national warning system]] in the United States designed to allow authorized officials to broadcast emergency alerts and warning messages to the public via [[Cable television|cable]], [[Satellite television|satellite]] and [[Terrestrial television|broadcast]] television and [[AM broadcasting|AM]], [[FM broadcasting|FM]] and [[Satellite radio|satellite]] radio. Informally, ''Emergency Alert System'' is sometimes conflated with its mobile phone counterpart [[Wireless Emergency Alerts]] (WEA), a different but related system. However, both the EAS and WEA, among other systems, are coordinated under the [[Integrated Public Alert and Warning System]] (IPAWS). The EAS, and more broadly IPAWS, allows federal, state, and local authorities to efficiently broadcast emergency alert and warning messages across multiple channels.<ref>{{cite web |url=https://www.fema.gov/integrated-public-alert-warning-system |title=Integrated Public Alert & Warning System |author=<!--Not stated--> |date=September 18, 2018 |website=fema.gov |publisher=Federal Emergency Management Agency |access-date=22 September 2018 |quote=IPAWS provides public safety officials with an effective way to alert and warn the public about serious emergencies using the Emergency Alert System (EAS), Wireless Emergency Alerts (WEA), the National Oceanic and Atmospheric Administration NOAA Weather Radio, and other public alerting systems from a single interface. |archive-date=September 22, 2018 |archive-url=https://web.archive.org/web/20180922211804/https://www.fema.gov/integrated-public-alert-warning-system |url-status=live }}</ref> The EAS became operational on January 1, 1997, after being approved by the [[Federal Communications Commission]] (FCC) in November 1994,<ref>{{cite web |title=What is Conelrad? EBS? EAS? |url=http://www.oldradio.com/current/bc_conel.htm |url-status=live |archive-url=https://web.archive.org/web/20150405012433/http://www.oldradio.com/current/bc_conel.htm |archive-date=April 5, 2015 |access-date=April 14, 2015}}</ref> replacing the [[Emergency Broadcast System]] (EBS), and largely supplanted [[Local Access Alert]] systems, though Local Access Alert systems are still used from time to time. Its main improvement over the EBS, and perhaps its most distinctive feature, is its application of a [[Audio frequency-shift keying|digitally encoded audio signal]] known as [[Emergency Alert System#Technical concept|Specific Area Message Encoding]] (SAME), which is responsible for the characteristic "screeching" or "chirping" sounds at the start and end of each message. The first signal is the "header" which encodes, among other information, the alert type and locations, or the ''specific area'' that should receive the message. The last short burst marks the end-of-message. These signals are read by specialized encoder-decoder equipment. This design allows for automated station-to-station relay of alerts to only the area the alert was intended for.

Like the Emergency Broadcast System, the system is primarily designed to allow the [[president of the United States]] to address the country via all radio and television stations in the event of a national emergency. Despite this, neither the system nor its predecessors have been used in this manner. The [[24-hour news cycle|ubiquity of news coverage]] in these situations, such as during the [[September 11 attacks]], has been credited to making usage of the system unnecessary or redundant.<ref name="Collins" /> In practice, it is used at a regional scale to distribute information regarding imminent threats to public safety, such as severe weather situations (including [[flash flood]]s and [[tornado]]es), [[AMBER Alert]]s, and other civil emergencies.

It is jointly coordinated by the [[Federal Emergency Management Agency]] (FEMA), the FCC, and the [[National Oceanic and Atmospheric Administration]] (NOAA). The EAS regulations and standards are governed by the Public Safety and Homeland Security Bureau of the FCC. All broadcast television, broadcast and [[satellite radio]] stations, as well as [[multichannel video programming distributor]]s (MVPDs), are required to participate in the system.