A Statistical Analysis of the Volcanic Activity at Stromboli, Italy by Mark

Four hundred eruptions of 3 active vents within the summit crater of the volcano Stromboli were recorded during 43.5 hours. The main vent (1) typically erupts pasty molten bombs in a 2 to 5 second burst with a mean frequency of 10.7 minutes. A second vent (2) normally fires a 1 second cannon-like burst of molten material averaging every 54 minutes. A third vent (3) predominantly erupts hot luminous gas for 2 minutes every 20.7 minutes on the average. Distributions of intereruption periods for all three vents imply that at a given time the eruption probability is independent of elapsed time from the previous eruption. Regression techniques applied to the intereruption periods at each vent together with parameters of activity at other vents (number of eruptions, time since last eruption) reveal a striking linear correlation of the activity at Vents 2 and 3 with the activity at Vent 1 (correlation coefficients were +0.986 and +0.87 for Vents 2 and 3 respectively). Physically this means the number of eruptions at Vent 1 is a far better indicator of the time to the next event at Vents 2iand 3 than any other parameter such as previous intereruption period; eruption duration, or time since the last