{"slug":"earthquakes","title":"Earthquakes","homepageTitle":"Earthquakes & Impacts","singular":"earthquake","article":"an","sources":[{"id":"noaa","label":"NOAA historical impacts","name":"NCEI/WDS Global Significant Earthquake Database","provider":"NOAA National Centers for Environmental Information / World Data Service","color":"#1e3a5f","citation":"NCEI / World Data Service: Global Significant Earthquake Database. NOAA National Centers for Environmental Information. DOI: 10.7289/V5TD9V7K. Accessed 7 September 2026.","license":"NOAA public data; cite NCEI/WDS and original references. Third-party source material retains its own rights.","url":"https://www.ncei.noaa.gov/products/natural-hazards/tsunamis-earthquakes-volcanoes/earthquakes","note":"Complete published NOAA significant-earthquake layer. Its inclusion criteria include deaths, substantial damage, magnitude at least 7.5, intensity X or greater, or an associated tsunami. Historical descriptions and impact counts vary in certainty and completeness."},{"id":"usgs","label":"USGS ComCat","name":"USGS ANSS Comprehensive Earthquake Catalog — significance ≥600","provider":"U.S. Geological Survey / ANSS and contributing seismic networks","color":"#9a642b","citation":"U.S. Geological Survey. ANSS Comprehensive Earthquake Catalog (ComCat), FDSN event service. Earthquakes from 1900-01-01 through 2026-09-07 00:00 UTC with significance ≥600. Accessed 7 September 2026. https://earthquake.usgs.gov/fdsnws/event/1/","license":"U.S. federal public data. Credit USGS, ANSS and contributing networks. Original event IDs, links and attributes are retained.","url":"https://earthquake.usgs.gov/fdsnws/event/1/","note":"Complete acquired query for the explicit period and significance threshold, downloaded in decade intervals. USGS significance combines magnitude, felt reports and PAGER alert information; it does not mean measured physical damage. PAGER is an automated estimate. USGS and NOAA can describe the same earthquake and remain separate source records without a shared identifier."}],"intro":"Explore significant earthquakes, documented historical impacts and instrumental event records from NOAA and USGS.","coverage":"NOAA global historical significant earthquakes and USGS significance ≥600 events since 1900, through 7 September 2026 00:00 UTC. A research snapshot, not a real-time alert service.","countNote":"Counts describe source records. NOAA and USGS inclusion criteria differ, and their catalogues can describe the same earthquake. USGS decade-query overlaps are reconciled only by exact provider event ID. Cross-provider records are not merged merely by proximity.","statisticsNote":"Statistics cover all source records matching the filters. Provider selection thresholds and historical reporting mean these are not global earthquake-rate estimates. Prefer the moment-magnitude variable when comparing event size; preferred magnitudes can use different scales. Unknown impact counts remain missing. Historical MMI, ShakeMap estimates and felt intensities are separate variables. Negative source years denote BCE.","measurementNote":"NOAA earthquake-attributed impact fields are displayed separately from the source’s combined disaster totals, which remain in original attributes. PAGER is a modelled potential-impact alert, not confirmed damage. Financial amounts are historical source estimates in millions of U.S. dollars; they are not inflation-adjusted. Do not sum overlapping source records.","methods":"All 6,634 NOAA layer records and 9,177 distinct USGS provider IDs from the acquired significance query are included. Partial NOAA dates remain partial. Original attributes and provenance are retained; no casualty values are inferred from qualitative ranges. USGS country labels are populated only where an explicit country/state is recognized in the supplied place text; offshore and unresolved labels remain unknown. Reported country and place-derived labels are distinguished by a separate field.","definition":"An earthquake occurs when rock suddenly slips along a fault, releasing energy as seismic waves. The underground starting point is the hypocentre; its projection on the surface is the epicentre. Shaking and impacts vary across the surrounding area.","definitionUrl":"https://www.usgs.gov/programs/earthquake-hazards/science-earthquakes","definitionSource":"USGS — The Science of Earthquakes","diagramAlt":"A cross-section showing a fault, an underground hypocentre, its surface epicentre and outward travelling seismic waves.","diagramCaption":"Earthquake source and surface location. A catalogue pin locates the epicentre, not the full area of shaking. Schematic; not to scale.","diagram":"Locating an earthquakeEpicentreHypocentreFaultSeismic waves","fields":[{"key":"momentMagnitude","label":"Moment magnitude","description":"Mw-family magnitudes only. NOAA Mw and USGS mw, mww, mwc and related moment-magnitude types are included.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"magnitude","label":"Preferred source magnitude","description":"Provider preferred magnitude. Scales vary; use the magnitude-type filter or the moment-magnitude variable for clearer comparison.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"depth","label":"Hypocentral depth","description":"Provider-reported depth in kilometres. Negative USGS depths can occur for shallow events and are retained. Not a surface elevation.","type":"numeric","unit":"km","group":"Measurements","scale":"linear"},{"key":"historicalIntensity","label":"Historical maximum MMI","description":"NOAA maximum Modified Mercalli Intensity, an ordinal historical assessment. Kept separate from ShakeMap and felt-intensity estimates.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"shakemapIntensity","label":"ShakeMap maximum MMI","description":"USGS ShakeMap estimated maximum Modified Mercalli Intensity. A modelled shaking estimate, not measured loss.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"feltIntensity","label":"Felt-report maximum intensity","description":"USGS DYFI maximum community-determined intensity. Its coverage depends on voluntary reports.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"feltResponses","label":"Felt responses","description":"Number of USGS Did You Feel It responses, not people affected.","type":"numeric","unit":"responses","group":"Measurements"},{"key":"deaths","label":"Reported earthquake deaths","description":"NOAA numerical earthquake-attributed death count. Qualitative ranges and combined disaster totals remain in original attributes. Do not add overlapping catalogues.","type":"numeric","unit":"people","group":"Measurements"},{"key":"injuries","label":"Reported earthquake injuries","description":"NOAA numerical earthquake-attributed injury counts. Unknown values remain missing.","type":"numeric","unit":"people","group":"Measurements"},{"key":"housesDestroyed","label":"Houses destroyed","description":"NOAA numerical reported count; source completeness varies.","type":"numeric","unit":"houses","group":"Measurements"},{"key":"housesDamaged","label":"Houses damaged","description":"NOAA numerical reported count, distinct from destroyed houses.","type":"numeric","unit":"houses","group":"Measurements"},{"key":"damageMillions","label":"Reported historical damage","description":"Source-reported earthquake damage in millions of U.S. dollars; historical currency values are not inflation adjusted.","type":"numeric","unit":"million USD","group":"Measurements"},{"key":"year","label":"Reported year","description":"Provider year. Negative years denote BCE. Source coverage and selection change through time.","type":"numeric","group":"Chronology","scale":"linear"},{"key":"country","label":"Country, where supplied","description":"NOAA country or a recognized country/state explicitly named in the USGS place label; unresolved cases remain missing.","type":"categorical","group":"Location"},{"key":"source","label":"Source collection","description":"NOAA historical impacts or the USGS significance-filtered catalogue.","type":"categorical","group":"Provenance"},{"key":"kind","label":"Record type","description":"Historical impact account or instrumental preferred event solution.","type":"categorical","group":"Provenance"},{"key":"magnitudeType","label":"Magnitude type","description":"Source magnitude scale. Ambiguous NOAA preferred magnitude matches remain labelled for inspection.","type":"categorical","group":"Provenance"},{"key":"pagerAlert","label":"PAGER potential-impact alert","description":"USGS automated estimate of possible impacts. This is not confirmed damage or a present alert.","type":"categorical","group":"Provenance"},{"key":"reviewStatus","label":"USGS review status","description":"Provider status such as automatic or reviewed; not an independent NKUA assessment.","type":"categorical","group":"Provenance"},{"key":"tsunamiAssociation","label":"Tsunami source flag","description":"NOAA association flag or USGS link flag. The latter does not confirm tsunami occurrence.","type":"categorical","group":"Provenance"},{"key":"countryBasis","label":"Country attribution basis","description":"Distinguishes a provider country field from a country/state explicitly recognized in a source place label.","type":"categorical","group":"Provenance"}],"shardSize":250,"acquired":"7 September 2026","preparedAt":"2026-09-07T01:46:58.210471+00:00","recordCount":15811}