Figure 1From: An analysis of the issuance of volcanic alert levels during volcanic crisesClassification of the issuance of alert levels relative to eruptions. The VAL is plotted against time (number of days). The first 30-day window shows the time before the eruption onset. The red line denotes the onset of the eruption, the plot continues until the end of the eruption (in this example at day 60).Back to article page