Assessing global trends in lava flow impact events

The destruction of thousands of homes by lava flows of Nyiragongo volcano, Democratic Republic of Congo, and La Palma, Canary Islands, in 2021 serve as a reminder of the devastating impact of lava flows. However, studies on lava flow impacts on the built environment are relatively rare. We reviewed literature to compile a global dataset of lava flow impacts to buildings and infrastructure from ~3500 BCE to 2022 CE, and use this to assess temporal and spatial trends of events. Our findings show a recent increase in recorded events, and that these occur more frequently than previously thought, with almost four impact events per decade in the past 100 years. This is likely from population expansion and reflecting a recent increase in recording. The majority of recorded events were in Italy, USA, and Réunion Island, France, with a rise in records in Africa since 1800 and the most impacted structures at Nyiragongo volcano, DRC. Impact records have developed from qualitative eruption reports to quantitative impact assessments, and the majority of studies report a binary impact on structures; with towns and/or structures stated as either destroyed or unaffected. However, several reports give specific details of damage indicating that lava flow impacts may not be binary. The dataset provides a baseline to assess past impacts, and be updated as future studies reveal past lava flow impact events, or when future lava impact events occur.