Evaluating life-safety risk for fieldwork on active volcanoes: the volcano life risk estimator (VoLREst), a volcano observatory’s decision-support tool

Table 4 Timing and duration of Whakaari VoLREst risk calculations in 2016

Risk calculation date	Volcano Alert Level	Time window	Reason for calculation
18 January 2016	VAL 1	13 weeks	Previous calculation expired
18 April 2016	VAL 1	13 weeks	Previous calculation expired
28 April 2016	VAL 3	1 week	Change in VAL status (short-lived eruption night of 27 April)
2 May 2016	VAL 2	4 weeks	Change in VAL status
30 May 2016	VAL 1	4 weeks	Previous calculation expired
27 June 2016	VAL 1	13 weeks	Previous calculation expired
13 September 2016	VAL 3	1 week	Change in VAL status (minor ash venting on 13 September)
16 September 2016	VAL 2	4 weeks	Change in VAL status (on 15 September)
10 October 2016	VAL 1	4 weeks	Previous calculation set to expire later that week; routine risk calculations done on a Monday following weekly volcano monitoring team meeting, so the risk calculation done on a Monday prior to the previous calculation expiring to realign to standard schedule.
7 November 2016	VAL 1	13 weeks	Previous calculation expired

On both 9 May and 19 September the VAL was lowered from 2 to 1, but the decision was made as a monitoring team to keep the current risk calculation until it expired or there was a renewed increase in unrest or eruptive activity

ISSN: 2191-5040