Early Warning Systems

Early Warning Systems

Traditionally, scientists and emergency managers developed linear models to identify key parties and information channels in EWSs. Models predicted that the flow of information starts when scientists observe a hazard above a threshold (earthquake magnitude). Scientists analyze the data and contact emergency managers to issue an alert if a critical threshold is reached. Emergency managers then make decisions about whether to notify the media and public of the threat and recommend actions. The ultimate receiver of the message is generally considered to be the “public.” Such linear models usually misrepresent the warning process in two ways. First, they highlight technology by focusing on the detection and emergency management subsystems, minimizing the public subsystem. This detracts from research findings that the public's first source of information and hence the beginning of [Page 306]response efforts is often human sensory experience with “natural warnings” or “environmental cues” that often precede the hazard (“feeling” ground motion in earthquakes). Moreover, research has shown that people's first source of warning is often “informal warnings,” received and disseminated through multiple channels (face-to-face contact, cell phones, TV). Additionally, through the use of “social cues,” people look to what others are doing to decide how to respond. Second, warnings meant for and disseminated to emergency managers are sometimes simultaneously received by media and the public. This means that messages are being acted on by the media and public before emergency managers have reviewed a warning and coordinated their response recommendations.

Figure 1 Model of an effective warning system

Another problem with many EWSs is that responsibility for providing warnings is divided between federal and local government agencies whose mandates are sometimes different. Scientists often have the mandate to provide warnings to emergency management, but recommendations for protective action are the responsibility of local and state emergency managers. This particular division of responsibility for the management of crises requires that warnings or recommended responses are issued at multiple levels of government, at differing times, and by different entities. Predicting social response is made even more difficult when one acknowledges that prior to receipt of official warnings, people are responding to (1) initial natural warnings or environmental cues, (2) informal warnings from each other and the media, and (3) social cues. Moreover, official warning messages are rewritten by numerous government agencies and redisseminated to multiple receivers. This leads to numerous message sources, which has been shown to improve response to warnings by decreasing the time taken to confirm warnings, but this is contingent on the content of the messages being the same. Some argue that there is simply a digital information overload. Furthermore, rewriting messages increases the likelihood of human error in translation, which delays response because people seek additional information to sort out any discrepancies, offsetting the positive effect provided by multiple message sources.

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