When the earth doesn’t stop shaking: How experiences over time influenced information needs, communication, and interpretation of aftershock information during the Canterbury Earthquake Sequence, New Zealand

The Canterbury Earthquake Sequence (CES) began with the Darfield earthquake on 4
September 2010. Continual large and small aftershocks since that time have meant
communities have cycled through repeated periods of impact, response and recovery.
Scientific communication about aftershocks during such a prolonged sequence has faced
distinct challenges. We conducted research to better understand aftershock information needs
for agencies and the public, and how people interpreted and responded to such information.
We found that a wide range of information was needed from basic facts about aftershocks
through to more technical information, and in different formats (e.g. maps, tables, graphs,
text, analogies). Information needs also evolved throughout the sequence, and differed
depending on people’s roles and experiences, and the phase of impact, response and recovery
communities were in. Interpretation of aftershock information was influenced by a variety of
factors including how understandable and relevant the information was, whether people had
prior knowledge or experience of aftershocks, whether the information was personalised or
contextualised, emotions and feelings, credibility and trust, and external influences. Given
that such a diversity of evolving information is required, it is imperative that geoscientists
strategize how to provide such information before a significant earthquake occurs.