The average number of fatalities per fatal incident and the probability of fatalities are broadly correlated with VEI.
Figure 12 a) Distribution of fatalities and fatal incidents across VEI levels; b) Average number of fatalities per fatal incident across VEI levels; c) Percentage of all events (fatal and non-fatal) of given VEI to have caused fatalities.
An average of over 300 fatalities per fatal incident was recorded in the 17th century, falling to below 100 in the 20th.
Consequently, the average number of fatalities per year has risen with time, whilst the average number of fatalities per fatal incident has fallen.
However, the number of fatalities per fatal incident declines from an average of over 400 to less than 100 between 1600 and 2010.
Figure 8 shows the average number of fatalities per fatal incident over time; though noisy, the measure is generally decreasing over time.
The decreases in the average number of fatalities per fatal incident and VFI over time (Figures 8 and 17) are most significant from the late 1700s onwards.
The average number of fatalities per fatal incident is increasing with VEI, from VEI 0 incidents which cause an average of 49 fatalities, to VEI 6 incidents which cause an average of 1,906.
Auker et al. (2013) found that the average number of fatalities per fatal incident increases back in time over the last four centuries, indicating that small events were less well recorded than large ones.
Fig. 7 The relationship between eruption size (VEI), the fatal cause, number of fatalities (bubble size) and fatal incident distance.
For 96 of the 289 fatal incidents for which two or more sources record a fatal incident, there is disagreement regarding the number of fatalities.
