Paired-event analysis of risk dynamics for nine paired earthquake events

Abstract The likelihood of multi-hazard disasters is expected to increase in the future. Existing research predominantly focuses on single hazards, often disregarding the interconnectedness between paired events. In this study, we examine how impacts and risk drivers (hazard, exposure, vulnerability, and management shortcomings) change between nine paired earthquake events that occurred between 2004-2021. We use the paired events approach developed for flooding, and expand the methodology to the case of paired earthquake events. We find evidence to suggest that societal learning may have taken place in regions that have been hit by previous earthquakes, where disaster risk reduction measures have been taken to reduce risk to future events. Vulnerability was lower in the second event than in the first event in all but one paired event (with no change in that event). There was a decrease in management shortcomings between the majority of the paired events. In terms of exposure, we find a heterogeneous pattern. We find that societies remain challenged by unprecedented events, i.e., events of a magnitude not previously experienced. We suggest that future studies should extend the paired-events methodology to look at other pairs of hazards. Moreover, we recommend carrying out paired event studies that examine changes in impact, hazard, exposure, vulnerability, and management shortcomings between different kinds of hazards (e.g., floods followed by earthquakes, volcanic eruptions followed by droughts, etc.). This would allow us to explore risk dynamics that result from paired events regardless of the event type, thereby unravelling the contributions of different risk drivers.