Evidence-based guidelines for protective actions and earthquake early warning systems

Abstract

Earthquake early warning systems (EEW) are becoming increasingly available or in development throughout the world. With public alerting in Mexico, Japan, Taiwan, and parts of the United States, it is important to provide evidence-based recommendations for protective action so people can protect themselves when they receive an alert. Best-practice warning communication research suggests that providing a protective action will increase the efficacy of the message. However, given the diversity of earthquakes and building types, as well as social and cultural contexts where these systems exist, the question is: what is the best protective action to recommend? The answer lies in maximizing life-saving protective actions during an earthquake event requires both contextually relevant messaging and widespread public education about appropriate protective actions under a range of conditions. By researching previous earthquake injury literature, examining current best practices and public education campaigns, key protective actions may be determined and used to increase the life-saving potential of earthquake early warning systems.

How Low Should We Alert? Quantifying Intensity Threshold Alerting Strategies for Earthquake Early Warning in the United States

“…While this alert threshold does not minimize missed alerts at the MMI 4.0 target threshold, the MMI 3.5 alert threshold still yields >85% correct alerts for this target threshold, with nearly all missed alerts in locations that experience MMI 4.0–4.5 (i.e., non‐damaging shaking). This all implies communication strategies consistent with current ShakeAlert operations for EEW alerts delivered through the WEA System: alerts are sent at MMI 3.5 in order to minimize missed alerts to locations that experience potentially damaging shaking (MMI 4.5+) that may cause injury (e.g., McBride, Smith et al., 2021; Porter & Jones, 2018).…”

Considerations for creating equitable and inclusive communication campaigns associated with ShakeAlert, the earthquake early warning system for the West Coast of the USA

“…Emergency preparedness campaigns often use a one size fits all approach; however, risk messaging is multidimensional and needs to account for audience characteristics to be effective (Mileti and Fitzpatrick, 1992;Herovic et al, 2014). Few studies have analyzed strategic communication efforts and campaigns targeted at diverse publics prior to earthquake events or during the recovery and aid process (Liu, 2007;Moore et al, 2004;Marti et al, 2020;McBride et al, 2021). Baker and Cormier (2015), Bolin and Kurtz (2018) and Julca (2012) argue that the unique needs of economically vulnerable and marginalized communities are routinely neglected.…”

“…Based on these definitions, issues of DEI are fundamentally connected to an individual or group's level of social vulnerability (for a complete review of social vulnerability definitions, see Tapsell et al, 2010). For earthquakes in particular, a person's age, gender, socioeconomic status and/or ability may influence their capacity to receive, comprehend and respond to ShakeAlert messages (McBride et al, 2021). Thus, campaigns associated with ShakeAlert are not detached from ideological systems of oppression, such as racism, classism and ableism.…”

The Seismic Early Warning System of Mexico (SASMEX): A Retrospective View and Future Challenges

“…Thus, in the case of high-rise buildings, evacuation at the sound of an alert may not be always the best option. In contrast, ShakeAlert encourages the population to Drop, Cover and Hold-On (DCHO) until the strong shaking passed (McBride et al, 2021). Although warning times for earthquakes in the Cascadia subduction zone may be 50-80 s (McGuire et al, 2021), this practice is advisable due to the proximity of the seismic sources to the target population centers in California, where warning times for ShakeAlert range from a few seconds to no more than 15 s. Clearly, evacuation with these short warning times is not a plausible option in most cases.…”