One single disaster event of at least this size.
Scrub forward to widen the window and watch cumulative probability grow.
Where the risk comes from
Time since last — is it overdue?
Probability vs. time
Frequency–severity
Season how the combined event rate moves through the year
Qualifying events
Deep history — extremes only centuries can rate occurrence probabilities over the same window · these sizes barely appear in the modern record
Windows follow documented completeness: VEI ≥ 6 since 1500 (Brown et al. 2014), VEI ≥ 7 since 900 (ice cores and tephra make these unmissable), M ≥ 8.5 instrumental era only. Whether the pre-1900 climb in documented quakes (3 → 6 → 7 → 9 → 11 per century) is record-keeping or real is tested, not assumed: declustered rates across the century of constant detection are statistically flat (χ² 15.1, trend z 1.3 — see METHODOLOGY § 16), so the documentary record is shown below but never feeds these rates. Occurrence ≠ death toll: a VEI-7 today would be catastrophic, but its toll depends on where.
Documented catastrophes
Read this before quoting a number
About the model
Data. EM-DAT, the international disaster database (CRED / UCLouvain, Brussels — emdat.be), public table including historical events, snapshot 2026-08-31; 14,166 physical natural-hazard events 1900→2026 after aggregating per-country records and excluding epidemics (statistics truncated at 2026-04-30, where EM-DAT's entry lag begins). Used under EM-DAT's non-commercial terms with attribution.
Model. Event occurrences above an impact threshold are a superposition of per-hazard Poisson processes. Rates are empirical counts inside per-threshold completeness windows (larger disasters are reliably recorded further back: ≥10,000 deaths from 1900, ≥1,000 from 1930, ≥100 from 1990, ≥10 from 2000), with exact Poisson confidence intervals. Sub-annual windows apply a per-hazard monthly climatology (hurricane season is real). Damage uses EM-DAT's CPI-adjusted series.
Full methodology, citations, and limitations: METHODOLOGY.md. The earthquake deep-dive runs on the instrumental seismic catalog (195k events, live USGS top-up) and supports any point on Earth.