The Significant Volcanic Eruptions Database is a global listing of over 600 eruptions from 4360 BC to the present. A significant eruption is classified as one that meets at least one of the following criteria: caused fatalities, caused moderate damage (approximately $1 million or more), Volcanic Explosivity Index (VEI) of 6 or greater, generated a tsunami, or was associated with a significant earthquake. The database provides information on the latitude, longitude, elevation, type of volcano, last known eruption, VEI index, and socio-economic data such as the total number of casualties, injuries, houses destroyed, and houses damaged, and $ dollage damage estimates. References, political geography, and additional comments are also provided for each eruption. If the eruption was associated with a tsunami or significant earthquake, it is flagged and linked to the related database. For a complete list of current and past activity for all volcanoes on the planet active during the last 10,000 years, please see Smithsonian Institution's Global Volcanism Program (GVP).

The Significant Volcanic Eruption Database is a global listing of over 500 significant eruptions which includes information on the latitude, longitude, elevation, type of volcano, and last known eruption. A significant eruption is classified as one that meets at least one of the following criteria: caused fatalities, caused moderate damage (approximately $1 million or more), with a Volcanic Explosivity Index (VEI) of 6 or larger, caused a tsunami, or was associated with a major earthquake.

Acknowledgement

Foto von Tetiana Grypachevska auf Unsplash

The Significant Volcanic Eruption Database is a global listing of over 500 significant eruptions which includes information on the latitude, longitude, elevation, type of volcano, and last known eruption. A significant eruption is classified as one that meets at least one of the following criteria: caused fatalities, caused moderate damage (approximately $1 million or more), with a Volcanic Explosivity Index (VEI) of 6 or larger, caused a tsunami, or was associated with a major earthquake.

License: https://www.usa.gov/government-works

Global Volcano Hazard Frequency and Distribution is a 2.5 minute gridded data set based upon the National Geophysical Data Center (NGDC) Volcano Database spanning the period of 79 through 2000. This database includes nearly 4,000 volcanic events categorized as moderate or above (values 2 through 8) according to the Volcano Explosivity Index (VEI). Most volcanoes are georeferenced to the nearest tenth or hundredth of a degree with a few to the nearest thousandth of a degree. To produce the final output, the frequency of a volcanic hazard is computed for each grid cell, with the data set consequently being classified into deciles (10 classes of approximately equal number of grid cells). The higher the grid cell value in the final output, the higher the relative frequency of hazard posed by volcanoes. This data set is the result of collaboration among the Columbia University Center for Hazards and Risk Research (CHRR) and Columbia University Center for International Earth Science Information Network (CIESIN).

The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain built up around the opening by the eruptive products. This slide set depicts ash clouds, fire fountains, lava flows, spatter cones, glowing avalanches, and steam eruptions from 18 volcanoes in 13 countries. Volcano types include strato, cinder cone, basaltic shield, complex, and island-forming. Perhaps no force of nature arouses more awe and wonder than that of a volcanic eruption. Volcanoes can be ruthless destroyers. Primitive people offered sacrifices to stem the tide of such eruptions and many of their legends were centered around volcanic activity. Volcanoes are also benefactors. Volcanic processes have liberated gases of the atmosphere and water in our lakes and oceans from the rocks deep beneath Earth's surface. The fertility of the soil is greatly enhanced by volcanic eruptive products. Land masses such as islands and large sections of continents may owe their existence entirely to volcanic activity. The "volcano" is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain built up around the opening by the eruptive products. The molten rock material generated within Earth that feeds volcanoes is called magma and the storage reservoir near the surface is called the magmachamber. Eruptive products include lava (fluid rock material) and pyroclastics or tephra (fragmentary solid or liquid rock material). Tephra includes volcanic ash, lapilli (fragments between 2 and 64 mm), blocks, and bombs. Low viscosity lava can spread great distances from the vent. Higher viscosity produces thicker lava flows that cover less area. Lava may formlava lakes of fluid rock in summit craters or in pit craters on the flanks of shield volcanoes. When the lava issues vertically from a central vent or a fissure in a rhythmic, jet-like eruption, it produces a lava fountain. Pyroclastic (fire-broken) rocks and rock fragments are products of explosive eruptions. These may be ejected more or less vertically, thenfall back to Earth in the form of ash fall deposits. Pyroclastic flows result when the eruptive fragments follow the contours of the volcano and surrounding terrain. They are of three main types: glowing ash clouds, ash flows, and mudflows. A glowing ash cloud (nuee ardente) consists of an avalanche of incandescent volcanic fragments suspended on a cushion of air or expanding volcanic gas. This cloud forms from the collapse of a vertical ash eruption, from a directed blast, or is the result of the disintegration of a lava dome. Temperatures in the glowing cloud can reach 1,000 deg C and velocities of 150 km per hour. Ash flows resemble glowing ash clouds; however, their temperatures are much lower. Mudflows (lahars) consist of solid volcanic rock fragments held in water suspension. Some may be hot, but most occur as cold flows. They may reach speeds of 92 km per hour and extend to distances of several tens of kilometers. Large snow-covered volcanoes that erupt explosively are the principal sources of mud flows. Explosions can give rise to air shock waves and base surges. Air shock waves are generated as a result of the explosive introduction of volcanic ejecta into the atmosphere. A base surge may carry air, water, and solid debris outward from the volcano at the base of the vertical explosion column. Volcanic structures can take many forms. A few of the smaller structures built directly around vents include cinder, spatter, and lava cones. Thick lavas may pile up over their vents to form lava domes. Larger structures produced by low viscosity lava flows include lava plains and gently sloping cones known as a shield volcanoes. A stratovolcano (also known as a composite volcano) is built of successive layers of ash and lava. A volcano may consist of two or more cones side by side and is referred to as compound or complex. Sometimes a violent eruption will partially empty the underground reservoir of magma. The roof of the magma chamber may thenpartially or totally collapse. The resulting caldera may be filled by water. The volcanic structure tells us much about the nature of the eruptions.

The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain built up around the opening by the eruptive products. This slide set depicts ash clouds, fire fountains, lava flows, spatter cones, glowing avalanches, and steam eruptions from 18 volcanoes in 13 countries. Volcano types include strato, cinder cone, basaltic shield, complex, and island-forming. Perhaps no force of nature arouses more awe and wonder than that of a volcanic eruption. Volcanoes can be ruthless destroyers. Primitive people offered sacrifices to stem the tide of such eruptions and many of their legends were centered around volcanic activity. Volcanoes are also benefactors. Volcanic processes have liberated gases of the atmosphere and water in our lakes and oceans from the rocks deep beneath Earth's surface. The fertility of the soil is greatly enhanced by volcanic eruptive products. Land masses such as islands and large sections of continents may owe their existence entirely to volcanic activity. The "volcano" is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain built up around the opening by the eruptive products. The molten rock material generated within Earth that feeds volcanoes is called magma and the storage reservoir near the surface is called the magmachamber. Eruptive products include lava (fluid rock material) and pyroclastics or tephra (fragmentary solid or liquid rock material). Tephra includes volcanic ash, lapilli (fragments between 2 and 64 mm), blocks, and bombs. Low viscosity lava can spread great distances from the vent. Higher viscosity produces thicker lava flows that cover less area. Lava may formlava lakes of fluid rock in summit craters or in pit craters on the flanks of shield volcanoes. When the lava issues vertically from a central vent or a fissure in a rhythmic, jet-like eruption, it produces a lava fountain. Pyroclastic (fire-broken) rocks and rock fragments are products of explosive eruptions. These may be ejected more or less vertically, thenfall back to Earth in the form of ash fall deposits. Pyroclastic flows result when the eruptive fragments follow the contours of the volcano and surrounding terrain. They are of three main types: glowing ash clouds, ash flows, and mudflows. A glowing ash cloud (nuee ardente) consists of an avalanche of incandescent volcanic fragments suspended on a cushion of air or expanding volcanic gas. This cloud forms from the collapse of a vertical ash eruption, from a directed blast, or is the result of the disintegration of a lava dome. Temperatures in the glowing cloud can reach 1,000 deg C and velocities of 150 km per hour. Ash flows resemble glowing ash clouds; however, their temperatures are much lower. Mudflows (lahars) consist of solid volcanic rock fragments held in water suspension. Some may be hot, but most occur as cold flows. They may reach speeds of 92 km per hour and extend to distances of several tens of kilometers. Large snow-covered volcanoes that erupt explosively are the principal sources of mud flows. Explosions can give rise to air shock waves and base surges. Air shock waves are generated as a result of the explosive introduction of volcanic ejecta into the atmosphere. A base surge may carry air, water, and solid debris outward from the volcano at the base of the vertical explosion column. Volcanic structures can take many forms. A few of the smaller structures built directly around vents include cinder, spatter, and lava cones. Thick lavas may pile up over their vents to form lava domes. Larger structures produced by low viscosity lava flows include lava plains and gently sloping cones known as a shield volcanoes. A stratovolcano (also known as a composite volcano) is built of successive layers of ash and lava. A volcano may consist of two or more cones side by side and is referred to as compound or complex. Sometimes a violent eruption will partially empty the underground reservoir of magma. The roof of the magma chamber may thenpartially or totally collapse. The resulting caldera may be filled by water. The volcanic structure tells us much about the nature of the eruptions.

An updated, geospatial collection of volcanoes whose NASA EONET open-event records match Smithsonian and USGS eruptive-activity reporting.

This dataset contains 11,089 documented volcanic eruptions from 1,196 volcanoes worldwide, spanning the Holocene period (~12,000 years), sourced directly from the Smithsonian Institution's Global Volcanism Program (GVP) via their official GeoServer web service.

Data Cleaning & Documentation Methodology - Two source tables joined on Volcano_Number: an eruptions table (one row per eruption event) and a volcanoes table (location/geological metadata per volcano). - Zero duplicate eruption or volcano IDs, zero full duplicate rows. - Activity_Type retained, not filtered: 9,918 "Confirmed Eruption" + 1,171 "Uncertain Eruption". Both kept, "Uncertain" reflects unverifiable historical evidence, not fabrication, and dropping it would discard 10.6% of real data. Filter this column yourself if you want confirmed-only. - 266 eruptions (2.4%) have no matching volcano metadata (likely subsidiary vents or synonyms not separately catalogued). Kept and flagged via has_volcano_metadata rather than dropped. - One eruption predates the nominal Holocene window (~55,500 years ago, Golden Trout Creek, dated via cosmic ray exposure). Flagged via pre_holocene_outlier rather than removed, it's a real, sourced data point. - ExplosivityIndexMax (VEI) is null for 24.3% of eruptions. VEI can't always be determined for older/less-observed eruptions. Preserved as NaN rather than dropped or imputed, to avoid biasing toward recent, well-studied eruptions. - Date precision varies significantly and is explicitly flagged. Many historical eruptions are only known to the year or month, not the exact day. The source data uses placeholder dates rather than blanks: July 2nd appears to serve as a year-only-precision placeholder (confirmed via evidence method, 95% of these cite vague historical "Observations: Reported"), and the 16th of the month appears to serve as a month-only-precision placeholder (confirmed by its even spread across all 12 months, rather than genuine clustering). A start_date_precision column flags these as "year (probable placeholder)", "month (probable placeholder)" or "day" (assumed exact). This cannot be determined with 100% certainty per row, treat day/month-level precision with appropriate caution for fine-grained analysis. - Negative years indicate BCE, not an error (e.g. -8300 = 8300 BCE). - VEI values confirmed within the valid 0–8 scale, coordinates confirmed within valid lat/lon ranges, no eruptions logically ending before they start.

Global Volcanic Eruptions: Holocene Record

11,089 documented volcanic eruptions from 1,196 volcanoes worldwide, spanning the Holocene period (~12,000 years), sourced directly from the Smithsonian Institution's Global Volcanism Program (GVP) via their official GeoServer web service. One row per eruption event, joined to per-volcano location and geological metadata. Every ambiguous or edge-case record is flagged rather than dropped, so the dataset preserves the real shape of the… See the full description on the dataset page: https://huggingface.co/datasets/xquantize/global-volcanic-eruptions-holocene-record.

This dataset comprises MISR-derived output from a comprehensive analysis of Icelandic volcano eruptions (Eyjafjallajokull 2010, Grimsvotn 2011, Holuhraun 2014-2015). The data presented here are analyzed and discussed in the following paper: Flower, V.J.B., and R.A. Kahn, 2020. The evolution of Icelandic volcano emissions, as observed from space in the era of NASA’s Earth Observing System (EOS). J. Geophys. Res. Atmosph. (in press). The data is subdivided by volcano of origin, date and MISR orbit number. Within each case folder there are up to 11 files relating to an individual MISR overpass. Files include plume height records (from both the red and blue spectral bands) derived from the MISR INteractive eXplorer (MINX) program, displayed in: map view, downwind profile plot (along with the associated wind vectors retrieved at plume elevation), a histogram of retrieved plume heights and a text file containing the digital plume height values. An additional JPG is included delineating the plume analysis region, start point for assessing downwind distance, and input wind direction used to initialize the MINX retrieval. A final two files are generated from the MISR Research Aerosol (RA) retrieval algorithm (Limbacher, J.A., and R.A. Kahn, 2014. MISR Research-Aerosol-Algorithm: Refinements For Dark Water Retrievals. Atm. Meas. Tech. 7, 1-19, doi:10.5194/amt-7-1-2014). These files include the RA model output in HDF5, and an associated JPG of key derived variables (e.g. Aerosol Optical Depth, Angstrom Exponent, Single Scattering Albedo, Fraction of Non-Spherical components, model uncertainty classifications and example camera views). File numbers per folder vary depending on the retrieval conditions of specific observations. RA plume retrievals are limited when cloud cover was widespread or the solar radiance was insufficient to run the RA. In these cases the RA files are not included in the individual folders.

The Significant Volcanic Eruption Database is a global listing of over 500 significant eruptions which includes information on the latitude, longitude, elevation, type of volcano, and last known eruption. A significant eruption is classified as one that meets at least one of the following criteria: caused fatalities, caused moderate damage (approximately $1 million or more), with a Volcanic Explosivity Index (VEI) of 6 or larger, caused a tsunami, or was associated with a major earthquake.

The statistic shows the economic damage caused by major volcanic eruptions in the period from 1900 to 2016*. The volcanic eruption on ****************** in Indonesia caused a loss of approximately ****** million U.S. dollars.

This dataset is about volcanic eruptions around the world. It includes volcanoes that had a Volcanic Explosivity Index (VEI) of 2 or greater, or that had notable human impacts.

It provides the name of the volcano, its location, the year it erupted, what type of volcano it was, and several other interesting attributes, such as whether the eruption caused a tsunami or not.

Check the vocabulary link at the bottom of the display to find more details about VEI and the different volcanic agent…

Dataset Overview

A comprehensive record of 898 significant volcanic eruptions spanning 4360 BC to 2025, sourced from the NOAA NCEI HazEL database and enriched with 77 analytical columns.

Each record captures the eruption's physical characteristics (VEI, volcano type, elevation, tectonic region), human impact (deaths, injuries, structures destroyed, damage in USD), and derived intelligence including composite hazard scores, ejecta volume estimates, plume height, eruption agent decoding, and per-volcano return period analytics.

Country metadata is enriched from the REST Countries API. All 28 previously unmatched territories (Solomon Islands, DRC, Réunion, Caribbean islands, Pacific Ocean seamounts) have been manually resolved with verified geographic and demographic data.

Sources: NOAA NCEI HazEL · REST Countries API · Wikipedia eruption tables

DATA SCIENCE APPLICATIONS

• Logistic regression: predict whether an eruption causes casualties based on VEI, volcano type, and tectonic region
• Time series analysis: eruption frequency trends by decade and century
• Geospatial clustering: identify high-risk volcanic zones using lat/lon and tectonic region
• Survival analysis: model eruption return periods per volcano
• Correlation analysis: VEI vs. human impact, damage, and tsunami triggers
• Decision tree classification: predict damage tier from VEI and location
• Risk scoring: use composite_hazard_score for comparative volcano risk ranking
• Exploratory data analysis: 6,300+ years of volcanic activity patterns

Column Descriptors

noaa_event_id — NOAA NCEI internal record ID year — Year of eruption (negative = BC) month — Month (1–12, NaN for ancient events) day — Day (NaN for ancient events) eruption_date — Constructed ISO date string volcano_name — Volcano name per NOAA record location_description — Free-text geographic location country — Country of eruption latitude / longitude — Decimal degree coordinates elevation_m — Summit elevation in metres volcano_type — Morphological classification (e.g. Stratovolcano) vei — Volcanic Explosivity Index (0–7) vei_category — VEI label (Gentle → Super-Colossal) vei_risk_tier — Risk class derived from VEI ejecta_volume_km3_min — Minimum ejecta volume (km³) per VEI class energy_release_joules_approx — Approximate energy release in Joules est_plume_height_km — Estimated eruption column height (km) eruption_agent_codes — Raw NOAA agent code string (e.g. P,M,T) eruption_agent_decoded — Human-readable eruption type description eruption_status — Historical / Holocene / Radiocarbon etc. is_eruption — Boolean: confirmed eruption event is_significant — Boolean: meets NOAA significance threshold deaths_direct / deaths_total — Fatalities direct and including secondary effects injuries_direct / injuries_total missing_persons / missing_persons_total structures_destroyed / structures_destroyed_total damage_est_millions_usd — Estimated direct damage (millions USD) damage_total_millions_usd — Total damage including secondary effects damage_tier — No Damage / Limited / Moderate / Severe / Extreme damage_scale_direct/total — NOAA ordinal damage scale (1–4) human_impact_score — Composite impact score 0–100 (log-scaled) composite_hazard_score — Combined VEI + impact + tsunami/EQ bonus (0–100) has_casualties — Boolean: at least one death recorded linked_tsunami_event_id — Cross-reference to NOAA tsunami database linked_earthquake_event_id — Cross-reference to NOAA earthquake database tsunami_confirmed — Boolean: tsunami verified in NOAA tsunami DB tectonic_region — Volcanic arc / zone classification (10 zones) ring_of_fire — Boolean: located on Ring of Fire island_volcano — Boolean: oceanic or island volcano hemisphere_ns / hemisphere_ew — Hemisphere flags country_continent — Continent (REST Countries API) country_region — World Bank region country_subregion — Sub-region country_population — Country population (2024) country_area_km2 — Country area km² century / decade / era — Temporal classification labels season_northern_hemisphere — NH season at time of eruption volcano_eruption_count_in_dataset — Total eruptions per volcano in dataset avg_eruption_return_period_years — Average years between eruptions per volcano volcano_activity_category — Activity frequency label row_completenes...

This statistic displays the largest volcanic eruptions in history based on the volume tephra that was erupted. About ** million years ago, the Wha Wha Springs eruption produced more than 5500 cubic kilometers of ejecta in a week.

The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain built up around the opening by the eruptive products. This slide set depicts explosive eruptions, lava fountains and flows, stream eruptions, and fissure eruptions from 19 volcanoes in 13 countries. Volcano types represented in this set include strato, cinder cone, complex, fissure vent, lava dome, shield, and island-forming. Perhaps no force of nature arouses more awe and wonder than that of a volcanic eruption. Volcanoes can be ruthless destroyers. Primitive people offered sacrifices to stem the tide of such eruptions and many of their legends were centered around volcanic activity. Volcanoes are also benefactors. Volcanic processes have liberated gases of the atmosphere and water in our lakes and oceans from the rocks deep beneath Earth's surface. The fertility of the soil is greatly enhanced by volcanic eruptive products. Land masses such as islands and large sections of continents may owe their existence entirely to volcanic activity. The word "volcano" is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain built up around the opening by the eruptive products. The molten rock material generated within Earth that feeds volcanoes is called magma and the storage reservoir near the surface is called the magma chamber. Eruptive products include lava (fluid rock material) and pyroclastics or tephra (fragmentary solid or liquid rock material). Tephra includes volcanic ash, lapilli (fragments between 2 and 64 mm), blocks, and bombs. Low viscosity lava can spread great distances from the vent. Higher viscosity produces thicker lava flows that cover less area. Lava may form lava lakes of fluid rock in summit craters or in pit craters on the flanks of shield volcanoes. When the lava issues vertically from a central vent or a fissure in a rhythmic, jet-like eruption, it produces a lava fountain. Pyroclastic (fire-broken) rocks and rock fragments are products of explosive eruptions. These may be ejected more or less vertically, then fall back to Earth in the form of ash fall deposits. Pyroclastic flows result when the eruptive fragments follow the contours of the volcano and surrounding terrain. They are of three main types: glowing ash clouds, ash flows, and mudflows. A glowing ash cloud (nue ardente) consists of an avalanche of incandescent volcanic fragments suspended on a cushion of air or expanding volcanic gas. This cloud forms from the collapse of a vertical ash eruption, from a directed blast, or is the result of the disintegration of a lava dome. Temperatures in the glowing cloud can reach 1,000 deg C and velocities of 150 km per hour. Ash flows resemble glowing ash clouds; however, their temperatures are much lower. Mudflows (lahars) consist of solid volcanic rock fragments held in water suspension. Some may be hot, but most occur as cold flows. They may reach speeds of 92 km per hour and extend to distances of several tens of kilometers. Large snow-covered volcanoes that erupt explosively are the principal sources of mud flows. Explosions can give rise to air shock waves and base surges. Air shock waves are generated as a result of the explosive introduction of volcanic ejecta into the atmosphere. A base surge may carry air, water, and solid debris outward from the volcano at the base of the vertical explosion column. Volcanic structures can take many forms. A few of the smaller structures built directly around vents include cinder, spatter, and lava cones. Thick lavas may pile up over their vents to form lava domes. Larger structures produced by low viscosity lava flows include lava plains and gently sloping cones known as a shield volcanoes. A stratovolcano (also known as a composite volcano) is built of successive layers of ash and lava. A volcano may consist of two or more cones side by side and is referred to as compound or complex. Sometimes a violent eruption will partially empty the underground reservoir of magma. The roof of the magma chamber may then partially or totally collapse. The resulting caldera may be filled by water. The volcanic structure tells us much about the nature of the eruptions.

The California volcano locations, threat rank and hazard zones data release contains two shapefiles for download or use as a web map service. The California Volcanic Center Locations shapefile was created to provide a generalized location of volcano hazard sources. The California Volcano Hazard Zones shapefile was created from previously published hazard zone reports. Specific details about each file can be found in the metadata included with each file and the read-me document for this data release. Together, these files were used to define California Volcano Hazards for the GIS analysis that supports conclusions in the California's exposure to volcano hazards report. Geologists produce hazard zone maps to convey the types of hazards that may occur during future eruptions and to identify the areas of potential impact. Hazard zones are derived from detailed geologic studies that identify the type and extent of volcanic deposits created in past eruptions and on isotopic and paleomagnetic dating of the age and frequency of eruptions. Users of the information in this report should be aware that volcanic areas in California are the subject of continuing research and that refinement of volcano hazard zones are sure to come in subsequent years.
The volcano hazard zones provided in this report reflect a simplified compilation of the following peer-reviewed U.S. Geological Survey reports: 1) For Lassen Volcanic Center: Clynne, M.A., Robinson, J.E., Nathenson, M., and Muffler, L.J.P., 2012, Volcano hazards assessment for the Lassen region, northern California: U.S. Geological Survey Scientific Investigations Report 2012–5176–A, 47 p., 1 plate, scale 1:200,000, [Available at http://pubs.usgs.gov/sir/2012/5176/a], and, Robinson, J.E., Clynne, M.A., 2012, Lahar hazard zones for eruption-generated lahars in the Lassen Volcanic Center, California: U.S. Geological Survey Scientific Investigations Report 2012–5176–C, [Available at http://pubs.usgs.gov/sir/2012/5176/c]. 2) For Medicine Lake Volcano: Donnelly-Nolan, J.M, Nathenson, M., Champion, D.E., Ramsey, D.W., Lowenstern, J.B., and Ewert, J.W., 2007, Volcano hazards assessment for Medicine Lake volcano, northern California: U.S. Geological Scientific Investigations Report 2007–5174–A, 33 p., 1 plate, [Available at https://pubs.usgs.gov/sir/2007/5174/a, and, subsequent GIS compilation in Ramsey, D.W., Donnelly-Nolan, J.M., and Robinson, J.E., 2019, Hazard boundaries for the volcanic hazard assessment of Medicine Lake volcano, California: U.S. Geological Survey data release, available at https://doi.org/10.5066/P9SDH8E6.] 3) For Mount Shasta, Clear Lake volcanic field, Long Valley volcanic field, Ubehebe Craters, Salton Buttes: Miller, C.D., 1989, Potential hazards from future volcanic eruptions in California: U.S. Geological Survey Bulletin 1847, 17 p., 2 tables, 1 plate, scale 1:500,000. [Available at https://pubs.usgs.gov/bul/1847, and, subsequent GIS compilation in White, M.N., Ramsey, D.W., and Miller, C.D., 2011, Database for potential hazards from future volcanic eruptions in California: U.S. Geological Survey Data Series 661 (database for Bulletin 1847), available at http://pubs.usgs.gov/ds/661]. The studies above represent the work of numerous researchers occurring over a collective span of almost three decades. As a result, methodology, nomenclature, and level of geologic detail vary from one report to the next. The simplified hazard zone maps presented in this report maintain the scientific integrity of the reports listed above, while simplifying nomenclature and amalgamating information to provide a consistent, statewide portrayal of California’s volcano hazard zones. It is important to note that volcanic hazard zone boundaries are gradational in nature, with the severity of the hazard diminishing outward from the eruption site (vent), or, for the various flowage hazards, with increasing height above valley floors or basins. The simplified hazard zone maps in this report portray hazard boundaries as diffuse bands rather than as sharp lines. Diffuse boundaries give a qualitative sense of the level of uncertainty in the original data, and account for differences in geologic resolution (map scales) across the various published reports listed above. It is unlikely that all parts of a volcanic area will be impacted during an eruption. As a volcano reawakens, real-time monitoring of earthquakes, ground deformation, and gas emissions will provide the information needed to anticipate the vent location and geographic sectors most likely to be impacted. Specific hazards to people and property will depend on the eruption style, the volume of lava erupted, the location of the eruptive vent, and the eruption duration, as well as local meteorological and hydrological conditions.

Supplementary Material 3: Supplementary Table Krippner_et al_TableS2.csv: Summary statistics of the measurements from search engine Google grouped per misconception and volcanic event between 2017 and 2022, as reported in Figure 1 in the main text

The Significant Volcanic Eruption Database is a global listing of over 500 significant eruptions which includes information on the latitude, longitude, elevation, type of volcano, and last known eruption. A significant eruption is classified as one that meets at least one of the following criteria: caused fatalities, caused moderate damage (approximately $1 million or more), with a Volcanic Explosivity Index (VEI) of 6 or larger, caused a tsunami, or was associated with a major earthquake.

In 2023, there were approximately ** thousand people affected by volcanic activity, the lowest figure in one decade. The highest figure recorded in the period displayed was in 2018, with over *** million people affected by volcanic activity. That year, the Lower Puna eruption in Hawaii caused the evacuation of approximately ***** residents and damage to public and private infrastructure.