Historical Eruptions and their Frequency

Diagram showing all recorded eruptions since 1850, the time between eruptions varies between 17 – 37 years, with an average of 27.7 years.

Outline of legacy mudflows as mapped by Kugler 1959 superimposed on a Google Earth image. These flows underlie most of the current settlement in the area.

Outline of legacy mudflows as mapped by Kugler 1959 in the surface geological map. The area covered by the 1995 and 2018 eruptions are included, they are very small compared to the older flows. Either (1) legacy eruptions were much larger in the past, however historical records do no confirm this, (2) it is the result of numerous flows over many years , (3) the mapping of the flows is incorrect.

From Wall and Sawkins 1860