The updated fatalities database contains 635 records and 278,368 fatalities recorded since 1500 AD through any fatal cause. These records comprise 581 incidents, 19 of which are further subdivided into 73 sub-incidents, where fatalities are identified at multiple distances. Sub-incidents are hereafter combined under incidents for analysis. Of the total, 64 incidents and 61,612 fatalities are due to indirect fatal causes or seismicity: these are excluded and discussed separately in our analysis.

The difference in number of incidents and fatalities compared with Auker et al. (2013) arises from the updates to the data, which included both addition and removal of fatal events and adjustments to the number of fatalities recorded in some incidents.

Fatalities are recorded at 194 volcanoes in 38 countries (Fig. 1), with the highest number of incidents recorded in southeast and east Asia (~50%).

Fig. 1 The distribution of Holocene volcanoes and those with fatal incidents recorded since 1500 AD Full size image

A distance is identified for 456 of the 590 fatal incident records in the database; a major improvement on the 27 of 533 fatal incidents reported in Auker et al. (2013). Distances are either well-defined (n = 210, QL 1) or constrained to a distance range (n = 246, QL 2). Results are presented here with some contextual discussion; more focussed discussion is provided in Discussion.

Variation in fatal incidents and fatalities with distance

Our analysis with distance excludes fatal incidents due to indirect fatal causes or seismicity unless otherwise stated, and combines incidents and sub-incidents. Therefore, we consider 571 incidents with 216,756 fatalities. Of these incidents, 413 have a distance recorded.

The number of fatal incidents decreases with distance from volcanoes (Fig. 2). About a third of incidents (149/413) are recorded within 5 km, 63% (259/413) are recorded within 10 km, and 83% (343/413) within 20 km from the volcano (grey dashed line, Fig. 2). The data approximately fit a logarithmic trend (R2 = 0.91), but there is an inflection in the number of incidents recorded at about 10 km distance. This may be an artefact of the recording process when distances are constrained to a range: 43 QL 2 incidents are recorded at <10 km. The largest number of fatal incidents in any 5 km bin around the volcano occurs closest to the volcano, in the first 5 km. Despite this, these incidents only account for 6268 fatalities (<3% of total). Indeed, at 5 km to about 10 km the number of fatalities increases dramatically (Fig. 2), despite the lower number of incidents. About 47% of fatalities are recorded within 20 km. Over 50% of fatalities occur more than 20 km from the volcano, and are attributed to just 17% of the fatal incidents.

Fig. 2 Cumulative proportion of fatalities and fatal incidents with distance. QL 1 and QL 2max data are represented and shown for all fatal causes excluding indirect and seismicity. Data are binned in 1 km width bins at the maximum distance (e.g. incidents from 1.1 to 2 km are in 2 km bin) Full size image

The number of fatalities with distance is more variable (Fig. 2). Single incidents can account for large losses of life at different distances, resulting in markedly stepped appearance to the cumulative curves in Fig. 2. Just seven incidents (Table 3) account for a combined total of over 125,000 fatalities (about 58% of total fatalities). Lahars, tsunami and PDCs (and potentially tephra fall) caused these large losses of life; indirect and seismicity-related fatal causes are excluded. If these major incidents are excluded from the analysis about 70% of fatalities are recorded within 20 km.

Table 3 Seven largest incidents in terms of loss of life (not including indirect or seismicity-related fatal causes) Full size table

Distance and fatal cause

Fatal incidents are recorded across a range of distances for all fatal causes, and these ranges are variable between hazards (Fig. 3, Table 4). Despite a range of distances recorded up to 170 km, the median incident distance (for all eruptive hazards) is 8.4 km, with an arithmetic mean of 13.2 km.

Fig. 3 Box and whisker plot showing the range of distances recorded for fatal incidents by fatal cause. The graph combines QL1 and QL2max data. Each box marks the 25th to 75th percentile distances, with the black line marking the 50th percentile. Whiskers extend to the minimum and maximum distances recorded. All hazards includes all eruptive hazards, including where multiple or unknown, and excludes non-eruptive, seismic and indirect. The count n is the number of incidents with distance data Full size image

Table 4 Statistics for distance of fatal incidents by fatal cause, ordered by decreasing number of fatalities Full size table

About 40% of fatal incidents in the first 5 km are caused by ballistics (Fig. 4a). These have the most proximal average distances (Table 4), with just one ballistics incident recorded beyond 5 km (Fig. 5). Typically, each ballistics incident involved a small number of fatalities (Fig. 4b). The largest loss of life recorded through ballistics was recorded at Asama, Japan, in 1596, when ‘many’ (n = 100, Table 2) were killed (NCAVJ 4th Edition). More recently, 57 people lost their lives through ballistics at the summit of Ontake, Japan in 2014. Ballistics account for <1% of fatalities (367/216,756).

Fig. 4 Percentage of incidents (a) and fatalities (b) per fatal cause in 5 km bins to 50 km. Data include QL 1 and QL 2max categories. Q-gas is quiescent gas, SRY lahars is secondary lahars Full size image

Fig. 5 The cumulative percentage of fatal incidents by selected eruptive hazard with distance. Data include QL 1 and QL2max categories. Incidents are counted in 1 km bins. The curve for ‘all’ represents all eruptive hazards as per Fig. 4 Full size image

Gas and quiescent gas emissions are typically a proximal hazard (Table 4, Figs. 3, 4) with the greatest distances to the volcano recorded when gas emission occurred from a satellite vent. Distances from these satellite vents are provided in the database where known. Gas and quiescent gas are responsible for both individual casualties and incidents in which many died. The greatest loss of life (>1565) is recorded at Lake Nyos in 1986 (e.g. Barberi et al. 1989, Baxter 1989; see Section 3.4). Volcanic gas, inclusive of quiescent gas, accounts for 2283 fatalities (1%).

Although fatal incidents through PDCs are recorded over a large distance range (Table 4, Fig. 3), 50% of incidents are recorded up to 10 km and about 90% within 20 km (Fig. 5), demonstrating the relative rarity of extensive PDCs. The greatest extent recorded in our dataset is 80 km during the 1883 Krakatau eruption, when PDCs travelled across the sea to southern Sumatra and West Java (Carey et al. 1996). Although too old for inclusion in this database, earlier examples of human impacts at distances beyond this are known. Maeno and Taniguchi (2007) described human settlements in southern Kyushu as devastated by PDCs, which had reached at least 100 km during the 7.3 ka Kikai eruption, Japan. Single PDC incidents have accounted for large loss of life in the database: about half of the PDC-related deaths (~28,000) occurred in just one incident: the 1902 Mont Pelée eruption, Martinique. Within 10 km of the vent, PDCs contribute the largest proportion of fatalities (Fig. 4). PDCs account for 59,958 fatalities (28% of the total recorded). It is also likely that many of the fatalities in the Multiple category were due to PDCs, including a majority of the 12,000 direct fatalities at Tambora, Indonesia in 1815.

Fatal incidents from lavas occur at greater distances on average than PDCs (Table 4, Fig. 3), at least in part due to the measurement of distance from the volcano summit rather than the eruptive vent. The greatest distance recorded was during the 1823 eruption of Kilauea, Hawaii, when lavas emitted from a 10 km-long section of the rift rapidly inundated a village (Stearns, 1926) 29 km from the summit. The largest loss of life (~100–130) occurred during the 2002 eruption of Nyiragongo, Democratic Republic of Congo, when lava flows inundated the city of Goma (e.g. Komorowski et al. 2002–3). Lava flows account for 659 fatalities (< 1%).

Few explosive hydrothermal incidents are recorded (n = 6). These explosions (typically VEI 1) have localised effects around the explosion vent but can be located in geothermal areas away from the summit. Measured from the volcano summit, the farthest fatal incidents occurred at 20 km at Okataina, New Zealand; measured from the vent these occurred at <1 km (Table 4). The greatest number of fatalities in any one incident is recorded at Dieng Volcanic Complex, Indonesia, in 1939, when steam explosions caused ten deaths. Fatalities in explosive hydrothermal incidents will occur through the ejection of boiling water, mud, steam and ballistics, but are considered separately to other eruptive ballistics.

Tephra, lahars and tsunami become the dominant fatal causes for incidents and fatalities after about 15 km (Fig. 4).

Tephra fall is commonly the most widespread volcanic hazard (Jenkins et al. 2012). Despite the wide reach, about 80% of fatal incidents occur within 20 km (Figs. 3, 5), reflecting thicknesses of tephra that can threaten life (e.g. due to roof collapse) are deposited quite close to source. Occasionally, tephra can cause fatalities at great distances, typically through exacerbation of existing heart or lung conditions (Horwell and Baxter, 2006), as in a fatality recorded at 170 km during the 1912 eruption of Novarupta, U.S.A. (Hildreth and Fierstein, 2012). The largest loss of life due to tephra occurred during the 1902 eruption of Santa María, Guatemala, when an estimated 2000 died due to burial, building collapse and suffocation. The distance at which this burial occurred is unknown; however, Church et al. (1908) describes tephra at about 10 km of 2.1 to 3.7 m depth. Tephra accounts for 4315 fatalities (2%). Lightning is a frequent component of volcanic ash clouds and nine fatalities are recorded through lightning strikes (<1%).

The majority of fatal incidents at distances greater than 15 km are due to lahars (primary and secondary). Distance measurement from the summit can be misleading, as lahars can be generated away from the summit and bulk up and entrain water and debris along the flow, making the source dispersed along the flow. The greatest recorded (QL1) distance occurred in the 1985 eruption of Nevado del Ruiz, Colombia, when lahars inundated the town of Armero 46 km from the volcano. Approximately 25,000 people lost their lives in Armero and Chinchiná (~34 km from Nevado del Ruiz). Lahars and secondary lahars are responsible for 56,315 fatalities (26%).

Tsunami can also have widespread impacts. However, the identification of the location and numbers of tsunami-related fatalities is problematic. The incidents for which distance is identified occur from close to the volcano to distances beyond 100 km. The greatest recorded number of fatalities through volcanogenic tsunami was 36,000 in the 1883 eruption of Krakatau, Indonesia, at distances of up to 40 km. Tsunamis account for 56,822 fatalities (26%).

Distance, eruption VEI and fatal cause

The fatal incidents data are dominated by small-magnitude (VEI 3 and below) eruptions of fatal incidents, 69% are associated with VEI 1–3 eruptions, 18% at VEI 4, and 13% at VEI 5–7. This dominance of smaller events reflects at least three main factors related to: the short time period of recording; systematic changes in recording of both eruptions and fatal incidents back in time that depend on eruption magnitude; and rapid population growth. Issues of incompleteness and under-recording are discussed further below. Unravelling these complexities will be challenging and will require a major modelling study which is well beyond the scope of this study. Here we analyse the data without any corrections and so our approach is empirical. The tendency for fatal incident distances to increase with eruption explosivity is illustrated in Fig. 6 for eruptions of VEI 5 and 6. Incidents in eruptions of VEI 4 show a less convincing increase in distance. There is no evidence for distance dependence for VEI ≤3.

Fig. 6 VEI and distance of fatal incidents across all fatal causes; non-eruptive, indirect and seismicity excluded. Data include QL 1 and QL2 max categories Full size image

Incidents individually accounting for over 100 fatalities are recorded in all VEI bands from 1 to 7: an increasing proportion of such incidents in each band is seen with increasing VEI. These incidents are recorded up to tens of kilometres from the volcano. There is no convincing relationship between VEI, the number of fatalities per incident and distance or fatal cause (Fig. 7).

Fig. 7 The relationship between eruption size (VEI), the fatal cause, number of fatalities (bubble size) and fatal incident distance. Data include QL 1 and 2max categories. *Lahars includes secondary lahars, and Gas includes quiescent gas Full size image

Fatalities during quiescence

Fatal incidents are recorded in periods of quiescence primarily due to secondary lahars (41 incidents, 6377 fatalities), quiescent gas emissions (50 incidents, >1600 fatalities) and indirect accidents (28 incidents, 30 fatalities).

The largest recorded loss of life from secondary lahars occurred in 1998 at Casita (San Cristóbal), Nicaragua. During Hurricane Mitch a debris avalanche transformed into a lahar which killed over 2500 in the towns of El Porvenir and Rolando Rodriguez (Scott et al. 2004) located at about 9 to 10 km from the volcano summit.

Quiescent gas emission was responsible for large numbers of fatalities in two events. Both occurred at volcanic lakes in the extensive Oku Volcanic Field, Cameroon: 37 fatalities at Lake Monoun in 1984 and >1565 fatalities at Lake Nyos in 1986. Both events involved non-eruptive lake-overturn (for Lake Monoun see Sigurdsson et al. 1987; for Lake Nyos see Kling et al. 1987), which released large volumes of carbon dioxide that flowed as dense currents into populated areas. Fatalities occurred at about 1 km from Lake Monoun. Baxter et al. (1989) and Barberi et al. (1989) showed that the majority of the Nyos fatalities occurred within 3 km of the lake, and all within 15 km.

The remaining quiescent gas emission incidents resulted in 96 fatalities. Many of these incidents involved small groups of recreational visitors close to craters and bathers in geothermal pools (Table 5, see section 3.5).

Table 5 Fatalities due to quiescent volcanic gas emission Full size table

Single fatalities occurred in 27 incidents through falls or misadventure. These incidents include a fall into the acidic crater lake at Kelimutu, Indonesia, a fall into a thermal mudpot at Mutnovsky, Russia, one incident at Rotorua, New Zealand and 23 incidents at Yellowstone, U.S.A., where the victims fell or jumped into thermal pools. Falls during eruptions, for example during tephra clean-up are considered separately.

Ten fatal incidents through seismicity are recorded. In most incidents there is ambiguity as to whether these were volcanic or tectonic events. Earthquakes have generated tsunamis resulting in fatalities in both eruptive and non-eruptive events.

At least two instances of fatalities associated with non-eruptive avalanches (e.g. flank collapse) and floods are recorded. An avalanche occurred at Mombacho, Nicaragua, during a storm in 1570 resulting in 400 fatalities. One hundred fatalities are recorded at Parker, Philippines, in 1640 after the caldera wall was breached draining the lake.

Victim classification

Information about the occupation, activities or place of residence of the fatalities can highlight vulnerabilities. Most fatal incident descriptions do not include such information about the victims. However, for those that do, several groups of victim occupation or activity stand out (Table 6): tourists, scientists (typically volcanologists), journalists, emergency responders and miners working in or near craters. Although rarely explicitly stated, the vast majority of fatalities are assumed to be local residents. We describe our findings in more detail for tourists, scientists, media and emergency response personnel in the following sections.

Table 6 Groups identified as being involved in numerous fatal incidents. Note that local residents will be the largest group by far Full size table

Tourists

One hundred and thirteen incidents with 561 fatalities are associated with tourism or recreation, including tourists, spectators, tourism-related park employees, climbers, campers, students, religious pilgrims and other recreational visitors to volcanoes. These are hereafter grouped as tourists. Fatal incidents occurred in both times of eruption and quiescence.

In times of eruption 480 fatalities are recorded in 69 fatal incidents. 55% of these incidents involved more than one fatality. All of the victims were outside at the time of eruption. Forty-seven of these incidents and 88% of fatalities (424/480) occurred within 5 km of the volcano. Ballistics were the most common fatal cause (31 incidents (45%), 164 deaths (34%)).

Persistent volcanic activity can result in hazard footprints that rarely extend beyond the crater. Such regular activity can engender complacency in tourists and guides, although small changes in activity, topography or wind direction can change the hazard footprint. At least 22 eruptive (and 5 indirect) fatal incidents occurred more than 1 year after the eruption start date, commonly at volcanoes known for regular activity. Long-lived eruptions affect analysis of relationships with VEI, as the VEI in GVP (2013) normally represents the tephra volume over the full length of the eruption. Ninety-one of the 113 incidents (81%) occurred during quiescence or low-explosivity eruptions of VEI 0–2.

Eighty-one fatalities occurred in 44 fatal incidents in periods of quiescence of which only 10 incidents involved more than one death. Non-eruptive fatal causes are gas (56 fatalities, 19 incidents) and indirect (25 fatalities, 25 incidents). These latter data are, however, strongly biased by data from Yellowstone, USA, which includes 23 incidents involving singular fatalities.

In times of quiescence hazards can be less obvious, with gas in particular representing a potentially invisible hazard. A good example is the six tourists who died in five incidents through quiescent degassing at Asosan, Japan, between 1989 and 1997 (Table 5). Ng’Walali et al. (1999) found that most of these victims had pre-existing pulmonary conditions, highlighting the increased risk to those with chronic lung disease. Gas monitoring devices and warnings were introduced in 1996. The two deaths in 1997 and the work of Ng’Walali et al. (1999) resulted in adjustments to the sulphur dioxide levels required to restrict access to the crater: no quiescent gas-related fatalities have been recorded at Asosan since.

Tourist co-operation is a requirement for safety in any volcanic setting, with visitors being relied upon to heed warnings and exercise appropriate caution. The 23 fatalities at Yellowstone occurred between 1890 (Whittlesey, 1995) and 2016 (Mettler, 2016), where deaths resulted from immersion in the near boiling water of thermal pools. Whittlesey (1995) describes these as accidental falls and misadventure – where the victims believed the pools swimmable. Of these fatalities, nine (36%) were children younger than 10 years old. Educational and safety information is provided and safe boardwalks through thermal areas have been installed, yet injuries are still frequent as visitors choose to engage in risky behaviour (Lalasz, 2013). Despite the frequency of injuries, only two fatalities are recorded in the last 30 years at Yellowstone, suggesting safety measures have been largely successful and the visitor population has become more risk averse at this volcano. Seventeen deaths are recorded at Rotorua, New Zealand since 1946, of which at least seven were tourists. These fatalities occurred primarily at hot pools through quiescent gas emissions. The decrease in incidents over time seen at Yellowstone is not seen here, with seven incidents since 2000. Recommendations were made in 2010 aimed at improving safety at geothermal pools (Bassindale and Hosking, 2011).

Scientists

Twenty-two incidents are identified in which 67 volcanologists, other field scientists and those supporting their work died (Table 7). This includes volcano observers, field assistants, ship’s crew, geology students (on fieldwork), and a U.S. Fish and Wildlife Service volunteer. The latter two events are classed as indirect having resulted from falls into thermal features. The largest loss of scientists’ lives (31) occurred with the sinking of the research ship Kaiyo-maru. The ship and her crew had been dispatched with seven scientists to observe the submarine eruption of Bayonnaise Rocks, Japan, which struck and sank the ship (Minakami, 1956).

Table 7 Incidents in which volcanologists or field scientists died Full size table

All known scientist fatalities occurred within 11 km of volcanoes. Two locations are unknown, and the 1930 death of the volcano observer at Merapi, Indonesia, is located <15 km based on the extent of pyroclastic flows (Thouret et al. 2000). Including those killed over the submarine eruption, 49 fatalities (73% of the scientist fatalities) occurred in or near the crater (within 1 km), highlighting the danger to field scientists visiting the summit of active volcanoes.

As with tourists, the most commonly identified fatal cause for scientists is ballistics (7 incidents, 15 fatalities). Four PDCs resulted in nine fatalities, despite this being the dominant fatal cause for all volcanic fatalities (Table 4; Auker et al. 2013). About 75% of scientist fatalities (50% of incidents) occurred in eruptions of VEI 0–2.

Emergency response personnel

Disaster prevention and response personnel, military and emergency services working to evacuate, rescue or recover victims have also lost their lives: 32 soldiers died alongside a geologist in the 1982 eruption of El Chichón, Mexico, when a pyroclastic flow overran the town of Francisco León, about 5 km from the summit (Bulletin SEAN 07–05, GVP, 1982); 12 disaster prevention personnel and two policemen died in the 1991 Unzendake eruption (Ministry of Land, Infrastructure and Transport 2007) 4 km from the summit; eight rescuers were killed in a helicopter crash at Dieng Volcanic Complex, Indonesia, during evacuation efforts in 2017 (Jakarta Globe 2017); and two rescuers died in 2006 at Merapi, Indonesia, after taking shelter in a bunker which was buried by pyroclastic flows about 4 km from the summit (Wilson et al. 2007). A radio operator reporting on the activity of St. Helens in 1980 for the Washington Department of Emergency Services died in the PDC at about 12 km (Hunter, 2012b).

Although not classified as emergency responders, fatality records exist for individuals who perished during rescue and recovery efforts. At Rabaul, Papua New Guinea, in 1990, three were killed whilst attempting to recover the bodies of three friends and relatives who were overcome by volcanic gases in a vent (GVP, 1990). At Mammoth Mountain, USA, in 2006, two ski patrollers fell into a fumarole and were asphyxiated. Rescue efforts saw the further death of one colleague and hospitalisation of seven others (Cantrell and Young, 2009).

Media

Thirty media employees died in six incidents: within 1 km of the vent at Semeru (Indonesia), Santa María (Guatemala) and Pacaya (Guatemala); within 3 km at Sinabung (Indonesia); 4 km at Unzendake (Japan) and at about 13 km at St. Helens (USA). The lava dome collapse at Unzendake generated a PDC in 1991 (Nakada, 1999), resulting in the deaths of 43 people, including 16 journalists and four of the journalists’ drivers (Ministry of Land, Infrastructure and Transport, 2007). Victims at Unzendake, Sinabung, Pacaya and Semeru were within the declared danger zones.