Table 3 Data quality ratings to evaluate the quality of volcanic vulnerability data. We suggest that a precautionary approach should be taken where data could fall within two categories, assigning that data the lower quality rating option. For example, if a scientist witnesses an eruption but does not record the hazard intensity, then the ‘D’ quality rating should be assigned

A (highest)

Volcanic impacts documented following multiple (>5) eruptions with large (>50) data points, and statistically valid analytical modelling or experiments undertaken at multiple recorded hazard intensities.

B

Volcanic impacts observed post-eruption with recorded hazard intensity, and experimental studies or analytical calculations undertaken.

C

Volcanic impacts witnessed by expert observers (e.g. scientists, infrastructure operators) post-eruption, and hazard intensity recorded.

D

Volcanic impacts witnessed and/or reported post-eruption by lay observers (e.g. public, media)), and hazard intensity not recorded.

E (lowest)

Volcanic impacts are possible, but not observed or identified.