Behavioral Responses to ShakeAlert Messages: Is "Drop, Cover, Hold On!" Actionable?

The delivery of messages through the Wireless Emergency Alert warning system, including the ShakeAlert message for earthquake warnings, require testing to determine whether message recipients can adequately perform the instructed protective actions. This is imperative for the success of the system in reducing injury and saving lives.

We conducted a laboratory experiment that measured behavioral responses, message perceptions, and visual attention to ShakeAlert warning messages. We recruited 130 participants from a large southern university. Participants were exposed to one level of the variable "video type": either an educational video, instructing how to perform the "drop, cover, and hold on" protective actions, or a news video, depicting scenes from a recent earthquake and its aftermath. They then saw one level of the variable "message type": either an earthquake early warning message that contained only text, or text accompanied by protective action icons. Participants were told to perform the protective actions in the message and also completed a survey about prior earthquake experience and message perceptions.

Across conditions, participants were able to perform on average 68% of recommended protective actions. Most participants dropped to the ground, covered their head/neck, and hid under a table, but failed to hold on to the table. Individuals who viewed the instructional video prior to seeing the message performed significantly more protective actions, expressed greater understanding of the messages, and reported being less likely to seek additional information about the threat before acting compared with those who viewed the news video. The inclusion of instructional icons did not affect overall total fixation duration, regardless of video type. Open-ended survey responses demonstrate that there is some confusion regarding the "hold on" protective action.

The earthquake early warning message is generally understood, and participants are able to perform most of the recommended protective actions. Nevertheless, our results indicate that ongoing public education and training will improve people's ability to follow the recommendations.