Reported Alaska eruptions through time: 1760-2014 The early years on this graph are heavily influenced by just a few expedition log books and the writings of Father Veniaminof: the ~120 possible eruptions during the Russian American period come from fewer than 20 documents, and eruptions from 1867-1940 are also probably significantly under-observed and under-reported. Increases from 1880-present day are probably the result of increased population, communications, and travel, rather than an actual increase in volcanic eruptions.
Credit: Image courtesy of the AVO/ADGGS.