How often do volcanoes in Alaska erupt?
“Most reports of eruptive activity date from 1760 on although a few vague reports of eruptions exist between 1700 and 1760 (Grewingk, 1850). At least 265 historical eruptions have occurred at 29 Alaskan volcanoes and another 45 are possible since 1760 giving a frequency rate of 1.1 – 1.3 eruptions per year. Since many eruptions early in this period surely went unreported, this is a minimum figure. “The problem of estimating eruption frequency through an analysis of the historical record is well-illustrated in Fig. 5 where the number of eruptions per decade in the Aleutian Arc is plotted for the past 200 years. Reported eruptions show a general increase beginning in the 1870-1880 decade and continuing to the 1920-30 decade where the rate of increase levels off. This increase is assumed to represent expanded travel to this remote area and advances in rapid communication (i.e., newspapers and more recently radio) of eruptive events; interestingly enough, the decades including World Wars I
