The Importance of Data Visualisation in Volcanic Activity Bulletins, Aotearoa New Zealand

Visuals, consisting of graphs, photographs, and other visual aids, are sometimes used as part of Volcanic Activity Bulletins (VAB), the main product used to inform the public of Aotearoa New Zealand (NZ) of volcanic activity and its potential impacts. Despite visuals commonly being regarded as vital to support communicating complex science ideas to non-science audiences, they are used relatively infrequently in VABs. For Ruapehu and Whakaari/White Island, NZ’s two most active volcanoes, only 24 and 36%, respectively, of examined VABs included a visual. Taupō and Tongariro, less active volcanoes, had substantially higher proportions of VABs with visuals. Most visuals were used to explain scientific information or data, but few specifically to explain hazard or risk. Reasons for not incorporating visuals include: preparation time constraints, VABs that contained little new information so a visual is less beneficial, and visuals being an optional addition. VABs published during the first official unrest episode at Taupō, a large caldera volcano with substantial population and infrastructure at risk, all included bespoke graphs, likely owing to the increased importance of clear communication in that case. Evaluation of clarity of message, information, and data in VAB visuals by a small group of creators and consumers produced varied scores and comments, revealing different views about what constitutes an effective visual. The best scoring visuals were created specifically for VABs, and the poorest scoring was a technical, internal monitoring product incorporated directly into a VAB without modification. The value of visuals in helping communicate key messages is not in doubt, provided they are suitable for the intended audience. Areas for improvement include: ensuring each visual has a title that reinforces the key message; ensuring important data or observations are highlighted; considering the area of interest when using base maps and adding error bars to graphs only if relevant to the message. The importance of visuals is improved if volcanic activity and hazard information are viewed as communication rather than science products.