Human behavioral response to earthquake early warnings (EEW): Are alerts received on mobile phones inhibiting protective actions?

Earthquake Early Warning (EEW) systems alert residents in locations likely to be shaken by large earthquakes. Despite the short warning period from the reception of an EEW until the arrival of shaking, residents are expected to protect themselves during the available time. Contrary to such expectations, previous research has revealed that most people did not take protective actions after receiving an EEW. Additionally, it was revealed that most people received EEW messages via mobile phones. This study empirically examined the relationship between receiving an EEW on mobile phones and taking protective actions. In the first case, a survey (N = 3000) was conducted to investigate residents’ reactions immediately after receiving an EEW issued for the Tokyo metropolitan area on October 7, 2021, for an earthquake of magnitude 6.0. The results suggested that the most common reaction upon receiving an EEW was to consult mobile phones to better understand the message. Thus, mobile phones receive more attention than the impending danger, resulting in the loss of precious seconds that could be used to take protective actions. In the second case, a survey (N = 1000) was conducted on another EEW issued for an earthquake of magnitude 6.3, which occurred in Ishikawa Prefecture on May 5, 2023. The results were consistent with those of the first survey, suggesting that the findings described above are robust. Finally, this study discusses ways to mitigate the dangers associated with earthquakes based on the findings of these studies.