When the Earth Erupts
Mapping Significant Volcanic Eruptions Around the World  

Does a Greater VEI Mean More Deaths?
The VEI measures the explosiveness of a volcanic eruption on a scale from 0 to 8, with 0 representing non-explosive eruptions and 8 representing the most extreme, “apocalyptic” eruptions (USGS, 2022). While VEI provides an important measure of an eruption’s explosive power, exploring the data revealed an interesting insight: a higher VEI does not necessarily result in a higher death count. Some eruptions with relatively lower VEI values resulted in substantial loss of life, while some much more explosive eruptions had comparatively fewer fatalities. For example, the United States experienced its deadliest recorded eruption at a VEI of 4, resulting in approximately 5,400 deaths, while Peru experienced a higher-VEI eruption (6) with considerably fewer fatalities, at approximately 1,400 deaths. This suggests that the human impact of an eruption depends on more than just its explosive power. Factors such as the location of the volcano, nearby population density, warning systems, evacuation preparedness, and the type of hazards produced can all influence the number of lives affected.

To further explore this relationship, the interactive map and accompanying chart compare each country’s deadliest recorded eruption with its corresponding VEI. Exploring the map provides additional details about each eruption, including the volcano’s name and type, the year it occurred, and the number of lives lost. Select a country on the map to explore how the eruption’s VEI compares with its resulting loss of life.

This visualization could support decision-making by helping emergency managers and government officials better understand the potential human impacts associated with volcanic activity. Rather than relying solely on an eruption’s VEI to assess risk, decision-makers could consider historical fatalities alongside eruption characteristics and geographic location. This information could help identify areas where additional emergency planning, public education, monitoring, or evacuation preparedness may be especially important.

Explore the visualization below by selecting a country on the map or bar chart to compare its deadliest recorded eruption with other countries and examine the associated volcano type and VEI.

Data source: Tableau Resources

Yellowstone Volcano Observatory. (2022, December 26). The Volcanic Explosivity Index: A tool for comparing the sizes of explosive volcanic eruptions. U.S. Geological Survey. https://www.usgs.gov/observatories/yvo/news/volcanic-explosivity-index-a-tool-comparing-sizes-explosive-volcanic 

by: Nicole Vicenti