Reactions to earthquake hazard: Strengthening commercial buildings and voluntary earthquake safety checks on houses in Wellington, New Zealand

Although many countries have legislation requiring strengthening of earthquake prone buildings, there are significant obstacles to retrofitting these buildings to make them more resilient. This research examines actions in regard to earthquake prone commercial and public buildings in Wellington and checks on private homes following the 2010/2011 Canterbury earthquakes and the 2013 Seddon/Cook Strait earthquakes. The study obtained data on commercial and public buildings removed from the Wellington City Council Earthquake-prone Buildings List (EQPB List) from 2012 to 2016 due to various mitigation actions (e.g., demolition and strengthening). The study also obtained rates of self-initiated voluntary Quakecheck home assessments for the same period. Results indicate ongoing removal of significant numbers of buildings from the EQPB List in this period, with strengthening being the most frequent action. This finding suggests that despite real obstacles, various incentives including legislation are leading to consistent earthquake preparation over time, often before the legislative deadline. In contrast with the EQPB data, the Quakecheck data indicate a sharp but short-lived spike after the Seddon / Cook Strait earthquakes. As a marker of self-initiated mitigation action, this brief spike suggests that in the absence of relevant legislation or insurance incentives, citizens' actions are only briefly influenced by the experience of an earthquake. These contrasting findings for EQPBs and Quakechecks suggest the value of legislation to drive mitigation actions for all buildings.