Figure 2
From: An analysis of the issuance of volcanic alert levels during volcanic crises
Overall results from the study. Pie chart (A) shows the relative frequencies of Categories 1 – 5. There is a large difference in the sample sizes (n). N values for categories are,; Cat 1: 75, Cat 2: 76, Cat 3: 5, Cat 4: 28, and Cat 5: 10. Pie chart (B) shows the proportion of `UwE’ alerts as a percentage Categories 2-6, i.e. of total alerts less Category 1 (`Missed’).