Regional and global under-recording of large explosive eruptions in the last 1000 years

Recording probabilities for large-magnitude ( M ≥4) explosive eruptions are assessed regionally over the last 1000 years, using the LaMEVE database. Although the uncertainty is large, due to the scarcity of large eruptions, it does not swamp differences in recording probabilities across times and regions. Broadly, the results reflect the pattern of European colonial expansion. Iceland presents an interesting anomaly, with a declining recording probability—going back in time—conflicting with its long history of written records. However, this may be explained by the loss of records in the 17th and 18th centuries. Globally, we find that records of roughly 40% of large-magnitude explosive eruptions are missing. There is a marked difference in modern recording probabilities pre- and post-1980, which we attribute to changes in the way that the magnitude of large eruptions is assessed.