Evacuation Behavior and Information Needs of Wellington, Aotearoa New Zealand Residents Following the 5 March 2021 Mw 7.3 East Cape Earthquake

Abstract

At 2.27 a.m., on 5 March 2021, an Mw 7.3 earthquake occurred approximately 100 km off the East Cape of the North Island of Aotearoa New Zealand. This earthquake was felt across the entire country, including in the capital city of Wellington and the surrounding region. Previous work reports varied levels of tsunami evacuation behavior for natural warnings from earthquake shaking. To further explore this behavior, we surveyed residents of the Wellington region about their evacuation decisions following the 5 March East Cape earthquake, their motivations for evacuating or not evacuating, and their immediate information needs. Approximately one-third of those who felt the earthquake, and who were in a tsunami hazard zone, self-evacuated, similar to previous findings following a larger, closer earthquake in 2016. Reasons for evacuating immediately were evenly split over specific awareness of the National Emergency Management Agency’s “Long or strong, get gone” tsunami evacuation advice, general knowledge that earthquakes can trigger tsunami, and social influences. Among those who did not evacuate, common reasons included not receiving an official warning and not believing that the earthquake was strong enough to generate a tsunami. Most people sought information from GeoNet, an official provider of earthquake information, though civil defense and emergency management sources were less used than mainstream news and social media. Along with information about tsunami risk, people tended to seek or want general information about earthquake characteristics such as location and size. Overall, the findings suggest that current public education efforts to encourage people to recognize and act on natural warnings (i.e., earthquake shaking) rather than waiting for official advice should be continued, and that consideration should be given to encouraging the use of official information sources.

The Effects of Earthquake Experience on Intentions to Respond to Earthquake Early Warnings

“…Future research could also include more studies on EEW performance, including testing of the proposed algorithms combined with testing of the proposed alerting channels, to determine how much time people in Aotearoa New Zealand may have to respond to an alert. Additionally, in New Zealand, emergency mobile alerts (which are more similar to EEWs than other warnings such as flood sirens) have been sent for hazards such as expected or potential tsunami impacts (Vinnell et al, 2022). While the public tend to appreciate these warnings, there are misconceptions about how and when they are used (e.g., some people want an alert to tell them they are not at risk) which makes comparisons to EEW difficult.…”

Differences in perceived sources of uncertainty in natural hazards science advice: lessons for cross-disciplinary communication

“…Managing natural hazard events (NHEs) requires communicating the science of those hazards effectively to a diverse range of individuals, from planners to policymakers, or emergency responders to community members involved in hazard preparedness, mitigation, response, and recovery (Doyle and Becker, 2022). Recent events in Aotearoa New Zealand (AoNZ), such as Cyclone Gabrielle in 2023 and the Mw7.8 Kaikōura earthquake in 2016, demonstrated how communicating this science effectively, and in a manner that meets decision-makers' needs and perspectives, is vital to encourage appropriate individual responses to hazards, warnings, and advice (e.g., Vinnell et al, 2022). However, the effective communication of the uncertainty associated with this information is an ongoing challenge impacting how individuals trust, evaluate, and respond (or not) to a scientific message (Johnson and Slovic, 1995;Smithson, 1999;Miles and Frewer, 2003;Freudenburg et al, 2008;Wiedemann et al, 2008;Oreskes, 2015;Kovaka, 2019).…”