{
  "slug": "supervolcano-eruption",
  "question": "What are the odds of a supervolcano eruption in your lifetime?",
  "quick_answer": "A Yellowstone-class supereruption runs about 1 in 12,400 over a lifetime, from a per-year chance near 1 in 730,000. Nearly 1 in 5 US adults report fearing a large volcanic eruption, though almost no one loses sleep over it.\n",
  "category": "natural",
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Supervolcanoes occupy a peculiar niche in collective anxiety: most people have heard of Yellowstone's caldera and have a vague sense that an eruption would end civilization, yet almost nobody loses sleep over it. Periodic media cycles — triggered by minor seismic swarms or a clickbait headline about Yellowstone being \"overdue\" — briefly spike public concern before it recedes. No major polling organization tracks supervolcano worry specifically, but the cultural footprint (disaster films, YouTube doomsday compilations) suggests the perceived risk fluctuates between \"impossible\" and \"extinction event\" with little calibration in between.\n",
    "rough_estimate": "19.2% of US adults report being afraid or very afraid of a large volcanic eruption (Chapman Survey 2024)",
    "kind": "survey",
    "survey_source": {
      "title": "Chapman University Survey of American Fears, Wave 10 — Complete List of Fears 2024",
      "publisher": "Chapman University",
      "url": "https://www.chapman.edu/wilkinson/research-centers/babbie-center/_files/2024-csaf-fears-high-to-low.pdf",
      "year": 2024
    }
  },
  "native": {
    "display": "~1 in 730,000 per year (USGS estimate for Yellowstone VEI-8)",
    "numerator": 1,
    "denominator": 730000,
    "unit": "per year",
    "population": "Global population, any VEI-8 supereruption (Yellowstone-class)"
  },
  "normalized": {
    "lifetime_us_adult": 0.0000808,
    "display": "~1 in 12,400 lifetime",
    "log_value": -4.09,
    "assumptions": "USGS estimates the annual probability of a Yellowstone-class VEI-8 supereruption at approximately 1 in 730,000. The global geological catalogue of M8 (VEI-8) eruptions (Mason, Pyle & Oppenheimer 2004) shows a minimum frequency of ≈1.4 events per million years — one roughly every 700,000 years — over the past 36 Ma, so any single system such as Yellowstone accounts for a large share of that risk. Using the USGS per-year figure and compounding over 59 remaining adult years: 1 − (1 − 1/730,000)⁵⁹ ≈ 8.08 × 10⁻⁵. This is a statistical expectation over geological time; USGS notes this figure \"is probably an overestimate for the short term\" given the absence of precursory signals. The probability is global in scope — a VEI-8 eruption anywhere would produce a volcanic winter affecting the entire planet.\n",
    "uncertainty": {
      "low": 0.00002,
      "high": 0.00015
    },
    "scope": "global_adult_lifetime"
  },
  "sources": [
    {
      "url": "https://www.usgs.gov/volcanoes/yellowstone/questions-about-supervolcanoes",
      "title": "Questions About Supervolcanoes",
      "publisher": "U.S. Geological Survey",
      "source_type": "govt_report",
      "statistic": "Annual probability of a Yellowstone supereruption is approximately 1 in 730,000",
      "excerpt": "\"The annual probability of a Yellowstone eruption is approximately 1 in 730,000... Given Yellowstone's past history, the yearly probability of another caldera-forming eruption can be approximated as 1 in 730,000 or 0.00014%.\"\n",
      "source_date": "2024-01-15",
      "source_accessed": "2026-04-18",
      "archive_url": "http://web.archive.org/web/20260503094235/https://www.usgs.gov/volcanoes/yellowstone/questions-about-supervolcanoes",
      "calculation_notes": "USGS derives the 1-in-730,000 figure from Yellowstone's three caldera-forming eruptions over 2.1 million years (2.1M / 3 ≈ 700,000-year average interval, rounded to 730,000). Annual individual risk: 1/730,000 ≈ 1.37 × 10⁻⁶. Over 59 adult years: 1 − (1 − 1.37 × 10⁻⁶)⁵⁹ ≈ 8.08 × 10⁻⁵. This is the probability of experiencing a supereruption, not dying in one — mortality would depend on location, agricultural collapse severity, and societal response.\n"
    },
    {
      "url": "https://link.springer.com/article/10.1007/s00445-004-0355-9",
      "title": "The size and frequency of the largest explosive eruptions on Earth",
      "publisher": "Bulletin of Volcanology (Mason, Pyle, Oppenheimer)",
      "source_type": "peer_reviewed",
      "statistic": "M8 (VEI-8) eruptions recur roughly once per 700,000 years globally (minimum ≈1.4 events per million years over the past 36 Ma)",
      "excerpt": "\"Eruptions of size M8 and larger have occurred with a minimum frequency of ≈1.4 events/Ma in two pulses over the past 36 Ma. On the basis of the activity during the past 13.5 Ma, there is at least a 75% probability of a M8 eruption (>10¹⁵ kg) occurring within the next 1 Ma.\"\n",
      "source_date": "2004-11-01",
      "source_accessed": "2026-04-18",
      "archive_url": "http://web.archive.org/web/20251025065256/https://link.springer.com/article/10.1007/s00445-004-0355-9",
      "calculation_notes": "Mason, Pyle & Oppenheimer catalogue 47 known M≥8 eruptions, of which 42 fall in the past 36 Ma, giving a minimum global M8 frequency of ≈1.4 events/Ma — i.e. one roughly every 700,000 years, comparable to the USGS Yellowstone-specific interval when only a single system is considered. The record is incomplete (a minimum count), and other authors (e.g. Pyle 2000; Self 2006) place the effective supereruption recurrence at one per 100,000–200,000 years once undercounting is corrected. Because the older record is progressively less complete, the USGS single-system Yellowstone estimate is the more conservative, better-constrained figure used for the headline calculation.\n",
      "independence_note": "Mason et al. use a global geological catalogue of large explosive eruptions independent of USGS Yellowstone Volcano Observatory monitoring data.\n"
    },
    {
      "url": "https://www.usgs.gov/observatories/yvo/news/so-when-will-next-eruption-yellowstone-happen",
      "title": "So, when will the next eruption at Yellowstone happen?",
      "publisher": "U.S. Geological Survey (Yellowstone Volcano Observatory, Caldera Chronicles)",
      "source_type": "govt_report",
      "statistic": "Yellowstone is not 'overdue'; the ~0.001% annual eruption probability is likely an overestimate for the short term",
      "excerpt": "\"Based on our current knowledge of Yellowstone's eruptive history, the annual probability of a volcanic eruption is on the order of 0.001%, but even this low number is probably an overestimate for the short term.\"\n",
      "source_date": "2024-11-04",
      "source_accessed": "2026-04-18",
      "archive_url": "http://web.archive.org/web/20260219125524/https://www.usgs.gov/observatories/yvo/news/so-when-will-next-eruption-yellowstone-happen",
      "calculation_notes": "USGS explicitly cautions that the naive recurrence-interval calculation overstates near-term risk because Yellowstone shows no precursory magmatic signals consistent with an impending eruption. This caveat is reflected in the wide uncertainty band applied to the normalized lifetime figure.\n"
    }
  ],
  "comparison_anchors": [
    {
      "label": "Asteroid impact death (lifetime)",
      "lifetime_us_adult": 7.4e-7
    },
    {
      "label": "Lightning strike death (lifetime, US)",
      "lifetime_us_adult": 0.00000354
    },
    {
      "label": "Earthquake death (lifetime, US)",
      "lifetime_us_adult": 0.00024
    }
  ],
  "short_label": "Supervolcano eruption",
  "myth_framing": "overrated",
  "outcome_severity": "fatal",
  "exposure_pattern": "acute",
  "outcome_type": "existential",
  "valence": "negative",
  "caveats": "The \"lifetime probability\" of a supervolcano eruption shares the same statistical fiction as asteroid impact risk: the expected value is dominated by an event so rare that no human civilization has witnessed one. The last VEI-8 eruption (Taupo's Oruanui event) occurred roughly 26,500 years ago. The USGS figure of 1 in 730,000 per year is a frequency estimate from three data points over 2.1 million years — not a forecast. If a VEI-8 eruption did occur, the probability of individual death would depend heavily on proximity and the severity of the subsequent volcanic winter; global agricultural collapse could kill far more people than the eruption itself.\n",
  "quality_score": {
    "d1": 5,
    "d2": 5,
    "d3": 5,
    "d4": 4,
    "d5": 5,
    "d6": 5,
    "d7": 5,
    "d8": 5,
    "avg": 4.875,
    "scored_by": "claude-code-8d",
    "scored_at": "2026-05-25",
    "methodology_version": "1.2"
  },
  "reviewer": "quality-review-agent",
  "last_reviewed": "2026-04-19",
  "reviewed": true,
  "generated_at": "2026-04-18",
  "image": {
    "alt": "A solitary volcanic caldera silhouette against a muted sky, flat vector illustration with subdued warm tones."
  },
  "attribution": "Likelier — https://likelier.app",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single",
  "canonical_url": "https://likelier.app/supervolcano-eruption"
}