The Technology of End-to-End Communication: Sending the Message

Man-made warning systems, such as emergency alert system (EAS), telephones, weather radios, and sirens, are most effective for warning about tsunamis from distant sources. Man-made systems are also useful for “all clear” notifications for distant tsunamis and, if the equipment survives the earthquake, for local tsunamis as well. If “all clear” notifications are made rapidly enough, community disruption by false alarms would be reduced. Repeated false evacuations are costly not only in terms of lost revenue but in lost credibility. EAS stations include radio, television, and cable networks. Although telephone alerts can be activated by the emergency operation centers or local public safety dispatch centers, telephone lines could become overloaded with calls from people wanting to verify what they heard of if shaking is indeed an earthquake.