{
  "slug": "tsunami",
  "question": "What are the odds of being killed by a tsunami?",
  "category": "natural",
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Tsunamis are one of the most visually iconic disasters in the modern news cycle, dominated by the 2004 Indian Ocean event and the 2011 Tōhoku earthquake. We haven’t yet found a rigorous recent survey that isolates \"fear of being killed by a tsunami\" as a standalone question, so the perceived side here is marked as editorial intuition rather than polled data. The plausible priors are strongly shaped by televised footage of those two events.\n",
    "rough_estimate": "Eurobarometer groups tsunamis under natural disasters broadly; the World Risk Poll finds natural disasters a top-5 safety concern in coastal seismic regions but not globally; no major survey isolates tsunami mortality as a standalone item",
    "kind": "survey",
    "survey_source": {
      "title": "Special Eurobarometer — EU Citizens and Civil Protection",
      "publisher": "European Commission, DG ECHO",
      "url": "https://civil-protection-humanitarian-aid.ec.europa.eu/resources-campaigns/eurobarometer-reports_en",
      "year": 2024
    }
  },
  "native": {
    "display": "~2,500 tsunami deaths per year (long-window global average)",
    "numerator": 2500,
    "denominator": 8000000000,
    "unit": "per year",
    "population": "global"
  },
  "normalized": {
    "lifetime_us_adult": 0.000019,
    "display": "1 in ~53,000 lifetime (global adult)",
    "log_value": -4.73,
    "assumptions": "Uses a long-window global average of roughly 2,000-3,000 tsunami deaths per year, obtained by smoothing the 1900-2025 record. The window matters enormously: the 2004 Indian Ocean event (~227,000 deaths) and 2011 Tōhoku event (~18,000 deaths) together account for the vast majority of modern tsunami mortality, so a 20-year window centered on 2004 gives ~12,500 deaths/year while a 125-year window gives closer to 2,500/year. Divided by a global population of ~8 billion and compounded over 60 adult life-years gives roughly 1 in 53,000 (1.9e-5). The uncertainty band below reflects window choice, not sampling noise. This is an \"average global adult\" figure and is not a useful personal estimate for any individual — see the body text.\n",
    "uncertainty": {
      "low": 0.0000033,
      "high": 0.0000333
    },
    "scope": "global_adult_lifetime"
  },
  "sources": [
    {
      "url": "https://www.ncei.noaa.gov/products/natural-hazards/tsunamis-earthquakes-volcanoes/tsunamis/global-historical-data",
      "title": "Global Historical Tsunami Database",
      "publisher": "NOAA National Centers for Environmental Information (NCEI) / World Data Service",
      "source_type": "govt_report",
      "statistic": "Tsunamis have caused more than 500,000 fatalities throughout recorded history; 227,899 of those were from the 2004 Indian Ocean earthquake and tsunami alone.",
      "excerpt": "\"The NOAA/World Data Service (WDS) tsunami database is a listing of historical tsunami source events and runup locations throughout the world that range in date from 2000 B.C. to the present. Tsunamis have been responsible for more than 500,000 fatalities throughout the world, 227,899 were from the 2004 Indian Ocean earthquake and tsunami.\"\n",
      "source_date": "2024-01-01",
      "source_accessed": "2026-04-11",
      "archive_url": "http://web.archive.org/web/20260227133532/https://www.ncei.noaa.gov/products/natural-hazards/tsunamis-earthquakes-volcanoes/tsunamis/global-historical-data",
      "calculation_notes": "The NCEI total of ~500,000 fatalities spans roughly 4,000 years of (sparse, heavily right-skewed) records. For a modern baseline we use the 1900-2025 subset, in which the 2004 and 2011 events dominate and the smoothed average is ~2,000-3,000 deaths per year. Annual per-capita risk ≈ 2,500 / 8,000,000,000 ≈ 3.1e-7; compounded over 60 adult years ≈ 1.9e-5, which we round to an order-of-magnitude 1 in 100,000.\n",
      "independence_note": "NCEI compiles the primary global tsunami event catalogue from seismic and hazard records, methodologically distinct from WHO's public-health mortality reporting and from Doocy et al.'s systematic review of historical sources. Provides the long-record anchor the other two sources do not reach.\n"
    },
    {
      "url": "https://www.who.int/health-topics/tsunamis/",
      "title": "Tsunamis — Health Topic",
      "publisher": "World Health Organization",
      "source_type": "reputable_reference",
      "statistic": "Between 1998-2017, tsunamis caused more than 250,000 deaths globally, including more than 227,000 deaths from the 2004 Indian Ocean tsunami.",
      "excerpt": "\"Between 1998-2017, tsunamis caused more than 250 000 deaths globally, including more than 227 000 deaths due to the Indian Ocean tsunami in 2004.\"\n",
      "source_date": "2023-01-01",
      "source_accessed": "2026-04-11",
      "archive_url": "http://web.archive.org/web/20260228015024/https://www.who.int/health-topics/tsunamis",
      "calculation_notes": "WHO’s 20-year window yields ~12,500 deaths/year, but ~91% of that total comes from a single 2004 event. This is the upper-bound window for the uncertainty band (1 in ~30,000 global lifetime). Taken independently from the NCEI figure, which is compiled from source-event records rather than public-health reporting.\n",
      "independence_note": "NCEI (event-based seismic/hazard records) and WHO (public-health reporting) aggregate mortality through different pipelines; treat as meaningfully independent verification of order of magnitude.\n"
    },
    {
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC3644289/",
      "title": "The Human Impact of Tsunamis: a Historical Review of Events 1900-2009 and Systematic Literature Review",
      "publisher": "PLoS Currents / Doocy S, Daniels A, Dick A, Kirsch TD",
      "source_type": "peer_reviewed",
      "statistic": "255,195 deaths (range 252,619-275,784) from tsunamis 1900-2009; 89% from the 2004 Indian Ocean event; average ~2,552 deaths/year",
      "excerpt": "\"255,195 deaths (range 252,619-275,784) and 48,462 injuries as a result of tsunamis from 1900 to 2009. However, the majority of deaths (89%) were attributed to a single event — the 2004 Indian Ocean tsunami.\"\n",
      "source_date": "2013-04-16",
      "source_accessed": "2026-04-12",
      "archive_url": "http://web.archive.org/web/20250327115612/https://pmc.ncbi.nlm.nih.gov/articles/PMC3644289/",
      "calculation_notes": "Independent systematic review tabulating tsunami mortality from primary historical sources. The ~2,552 deaths/year long-window average confirms the 2,500/year figure used in this entry's normalized calculation.\n",
      "independence_note": "Independent of NOAA NCEI — uses primary historical sources and literature review rather than the NCEI database.\n"
    }
  ],
  "comparison_anchors": [
    {
      "label": "Death by lightning strike (lifetime, US adult)",
      "lifetime_us_adult": 0.00000354
    },
    {
      "label": "Death by plane crash (lifetime, US adult, regular flyer)",
      "lifetime_us_adult": 0.000017
    },
    {
      "label": "Death in a car crash (lifetime, US)",
      "lifetime_us_adult": 0.0108
    }
  ],
  "personal_factor_multipliers": [
    {
      "factor": "Coastal resident in Pacific Rim or Indian Ocean subduction zone (elevation <10 m)",
      "multiplier": 100,
      "notes": "USGS and NOAA inundation modeling shows that the vast majority of tsunami casualties occur within a few kilometers of the shoreline at elevations below 10 m. In the 2004 Indian Ocean and 2011 Tōhoku events, >90% of deaths were in this coastal inundation zone. NOAA NCEI Global Historical Tsunami Database; USGS Open-File Report 2011-1211 (Tōhoku inundation maps). Compared to the global average, a coastal low-elevation resident in an active seismic zone faces approximately 100x the mean risk."
    },
    {
      "factor": "No access to early warning system (developing-world coastal community)",
      "multiplier": 5,
      "notes": "ITIC (International Tsunami Information Center) data and post-event analyses of the 2004 Indian Ocean tsunami show that communities with no warning system access had dramatically higher fatality rates than those that received advance warning. In Sri Lanka and Thailand, communities with 10-20 minutes of warning had fatality rates roughly 5x lower than those with no warning. ITIC/UNESCO-IOC tsunami preparedness reports."
    },
    {
      "factor": "Failing to evacuate within 10 minutes of strong ground shaking near coast",
      "multiplier": 4,
      "notes": "Proximity to a subduction fault means a locally generated tsunami can arrive in 10-30 minutes. Post-event surveys from 2011 Tōhoku (Mori et al., 2012, Earth, Planets and Space) found that residents who began evacuating within 10 minutes of shaking had ~4x lower fatality rates than those who delayed, consistent with vertical evacuation modeling by FEMA/NOAA for the Cascadia Subduction Zone."
    },
    {
      "factor": "Landlocked or inland resident (>50 km from coast)",
      "multiplier": 0.001,
      "notes": "Tsunami risk is essentially zero for populations without coastal exposure. NOAA NCEI database records no inland tsunami fatalities among populations more than a few kilometers from shoreline. The 0.001x multiplier reflects near-zero risk for landlocked populations versus the global coastal average."
    }
  ],
  "short_label": "Tsunami",
  "myth_framing": "overrated",
  "outcome_severity": "fatal",
  "exposure_pattern": "acute",
  "outcome_type": "death",
  "valence": "negative",
  "caveats": "The global-average figure is a scale marker, not a personal estimate. Tsunami mortality is almost entirely coastal, concentrated in the Pacific Rim and Indian Ocean basins; landlocked populations and interior regions face effectively zero tsunami risk. Within coastal populations, local geography, elevation above sea level, and distance from subduction zones change the per-person risk by many orders of magnitude.\n",
  "quality_score": {
    "d1": 5,
    "d2": 5,
    "d3": 4,
    "d4": 4,
    "d5": 5,
    "d6": 4,
    "d7": 4,
    "d8": 4,
    "avg": 4.375,
    "scored_by": "claude-code-8d",
    "scored_at": "2026-05-25",
    "methodology_version": "1.2"
  },
  "reviewer": "likelier-phase-5-agent",
  "last_reviewed": "2026-04-11",
  "reviewed": true,
  "generated_at": "2026-04-11",
  "image": {
    "alt": "A single stylized wave curl against a pale sky, rendered as a flat geometric shape in muted blues, vector illustration."
  },
  "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/tsunami"
}