New Geo-Narrative explores California’s exposure to volcanic hazards

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The first step in mitigating volcanic risk and building community resilience to volcanic hazards is identifying what and who is in harm’s way.

Animated gif of user navigating through the menus and options of the exposure geonarrative as described in the paragraphs below.

Navigating through the geonarrative allows the user to explore the GIS data used for the exposure analysis in the California's Exposure to Volcanic Hazards report.

(Public domain.)

A new GIS-powered website “California’s Exposure to Volcanic Hazards Geo-Narrative” ( offers a novel way to interact with volcanic hazard maps, and explore the populations, infrastructure and resources in California’s volcanic hazard zones. This website has been created as a companion to the first-of-its-kind volcanic hazard exposure study published in collaboration with the California Office of Emergency Services and the California Geological Survey in 2019 (California’s Exposure to Volcanic Hazards, SIR 2018-5159). The report and the geo-narrative not only contain a broad perspective on the types of volcanic hazards and background knowledge on California’s volcanoes, they also provide an analysis of the potential impacts of future eruptions and unrest on populations, infrastructure and resources.

This GIS-based geo-narrative offers a new way to interact with the maps, data, and analyses in the exposure report. Like the report, it contains a primer on general and California-specific volcanic hazards, but adds a hands-on ‘dashboard’ which allows users to explore societal asset data at the county level, understand the varying exposure and mapped hazards of each volcano, and visualize the report’s data analyses in both tabular and graphical form. Ultimately, this information is intended to help decision-makers make location- and sector-specific vulnerability analyses, and prepare hazard mitigation and response plans.

Please contact Jeff Peters ( for technical questions about the geo-narrative, and with any questions about the data, original report, and their use. The data release for both the report and geo-narrative, including GIS files, can be found at