{"slug":"tsunamis","title":"Tsunamis","singular":"tsunami","sources":[{"id":"noaa-events","label":"NOAA events","name":"NOAA Global Historical Tsunami Database — events","provider":"NOAA NCEI / World Data Service","color":"#1e3a5f","citation":"NCEI / World Data Service: Global Historical Tsunami Database. NOAA National Centers for Environmental Information. DOI: 10.7289/V5PN93H7. Accessed 7 September 2026.","license":"NOAA public data; cite NCEI/WDS and the contributing references. Third-party source material retains its own rights.","url":"https://www.ncei.noaa.gov/products/natural-hazards/tsunamis-earthquakes-volcanoes/tsunamis","note":"Complete published event layer acquired on 7 September 2026. Historical reporting is uneven. Validity classes include doubtful and erroneous reports; these are preserved explicitly, not presented as independently confirmed events."},{"id":"noaa-observations","label":"NOAA observations","name":"NOAA Global Historical Tsunami Database — coastal observations","provider":"NOAA NCEI / World Data Service","color":"#9a642b","citation":"NCEI / World Data Service: Global Historical Tsunami Database. NOAA National Centers for Environmental Information. DOI: 10.7289/V5PN93H7. Accessed 7 September 2026.","license":"NOAA public data; cite NCEI/WDS and the contributing references. Third-party source material retains its own rights.","url":"https://noaa.maps.arcgis.com/home/item.html?id=33d29de9e6c34c44ab087d78c15e05d7","note":"Complete published observation layer. A coastal measurement is not another tsunami. TSEVENT_ID links observations to the source event. Measurements include different instruments and field-survey methods."},{"id":"greek-impact","label":"Greek impact database","name":"Greek Tsunami Impact Database 1800–2020","provider":"Ioanna Triantafyllou; Gerassimos Papadopoulos","color":"#0d9488","citation":"Triantafyllou, I. and Papadopoulos, G. (2023). Greek Tsunami Impact Database 1800–2020, v1. Zenodo. DOI: 10.5281/zenodo.10199521.","license":"CC BY 4.0. Changes: column normalization, explicit missing values and display coordinates; original attributes retained.","url":"https://zenodo.org/records/10199521","note":"Peer-reviewed studies and historical sources underpin the impact descriptions. The repository description mentions 16 events, but the downloadable CSV contains 15 populated event rows; blank rows are excluded. Reliability is the provider’s classification. Zero earthquake magnitudes for gravitative marine slides are not measured magnitudes."}],"intro":"Explore tsunami sources, coastal observations and documented impacts through maps, filters, search and statistics.","coverage":"NOAA global historical event and observation layers, plus the Greek impact catalogue for 1800–2020. This is a dated research snapshot.","countNote":"Counts describe source records. One tsunami can have many coastal observations and multiple historical accounts. NOAA event IDs link documented observations; Greek reports retain their own identity when there is no shared identifier. Records without coordinates remain searchable and included in relevant statistics.","statisticsNote":"Statistics describe filtered source records, not independent disasters or a globally complete hazard frequency. Select a record type or source before interpreting distributions. Event maxima and local water heights are separate variables. Missing values and qualitative casualty ranges are excluded from numerical calculations; they are never treated as zero. Negative years denote BCE using the source year convention.","measurementNote":"Reported water heights may use different measurement types and reference levels. Event and local impact figures must not be added together. Counts of casualties are source reports; unknown counts remain blank. Moment magnitude and Greek tsunami intensity use distinct scales.","methods":"The complete NOAA feature layers were downloaded in stable object-ID order with pagination. Stable NOAA ID and TSEVENT_ID fields supply provenance and event–observation links. Original text, classifications and coordinates are preserved. Greek blank rows and zero magnitude placeholders are excluded from numerical measures. No proximity-based merges or invented inundation polygons are made.","definition":"A tsunami is a series of long waves produced when a large volume of water is displaced abruptly, often by an earthquake, volcanic activity or a landslide. The waves can travel across an ocean and flood coastlines.","definitionUrl":"https://tsunami.noaa.gov/tsunami-story","definitionSource":"NOAA — The Tsunami Story","diagramAlt":"Schematic cross-section showing a seafloor disturbance generating long waves that propagate towards a shallow coast.","diagramCaption":"From a sudden water displacement to coastal flooding. Schematic cross-section; not to scale.","diagram":"How a tsunami travelsSudden displacementLong waves cross the oceanShallow coast","fields":[{"key":"waterHeight","label":"Observed water height","description":"Source-reported height at a coastal observation. Measurement types and vertical reference levels vary; use the measurement-type filter. Negative readings are retained.","type":"numeric","unit":"m","group":"Measurements","scale":"linear"},{"key":"eventMaxHeight","label":"Event maximum water height","description":"Maximum reported water height in the NOAA event record. Kept separate from individual observations.","type":"numeric","unit":"m","group":"Measurements"},{"key":"inundation","label":"Horizontal inundation distance","description":"Reported horizontal extent of coastal inundation at the observation site. Missing values are excluded.","type":"numeric","unit":"m","group":"Measurements"},{"key":"travelMinutes","label":"Observed travel time","description":"Source travel hours and minutes converted to minutes when both components are supplied. Partial travel times remain in original attributes. This is an observation, not a new modelled arrival time.","type":"numeric","unit":"min","group":"Measurements"},{"key":"distance","label":"Distance from source","description":"Source-reported distance between the tsunami source and coastal observation.","type":"numeric","unit":"km","group":"Measurements"},{"key":"period","label":"Reported wave period","description":"Period reported at the observation; source measurement conventions apply.","type":"numeric","unit":"min","group":"Measurements"},{"key":"magnitudeMw","label":"Source earthquake moment magnitude","description":"Moment magnitude Mw only. Other magnitude scales remain in original attributes. Zero placeholders in the Greek slide records are excluded.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"depth","label":"Source earthquake depth","description":"Provider-reported earthquake depth. Not a water depth. Greek non-earthquake zero placeholders are excluded.","type":"numeric","unit":"km","group":"Measurements"},{"key":"greekIntensity","label":"Greek tsunami intensity","description":"Papadopoulos–Imamura 12-grade tsunami intensity from the Greek impact database only. Not earthquake intensity.","type":"numeric","group":"Measurements","scale":"linear"},{"key":"deaths","label":"Reported deaths","description":"Numerical death counts as attributed by each source at its event or site scale. Never sum event counts with local counts or overlapping sources.","type":"numeric","unit":"people","group":"Measurements"},{"key":"injuries","label":"Reported injuries","description":"Numerical injury counts; qualitative reports remain in original attributes.","type":"numeric","unit":"people","group":"Measurements"},{"key":"year","label":"Reported year","description":"Year recorded by the provider. Negative years denote BCE. Reporting changes over time; this is not a hazard trend.","type":"numeric","group":"Chronology","scale":"linear"},{"key":"country","label":"Country","description":"Country named by the source, normalized to title case.","type":"categorical","group":"Location"},{"key":"source","label":"Source collection","description":"Agency or research collection providing the record.","type":"categorical","group":"Provenance"},{"key":"kind","label":"Record type","description":"An event origin, coastal observation or regional impact account.","type":"categorical","group":"Provenance"},{"key":"cause","label":"Reported cause","description":"Cause from the event provider; coastal observations inherit the linked NOAA event cause.","type":"categorical","group":"Provenance"},{"key":"validity","label":"Provider validity classification","description":"NOAA event validity and Greek reliability retain separate terminology. These are provider assessments, not NKUA verification.","type":"categorical","group":"Provenance"},{"key":"measurementType","label":"Measurement type","description":"NOAA observation method, such as tide gauge or field survey.","type":"categorical","group":"Provenance"},{"key":"doubtful","label":"Observation doubt flag","description":"NOAA observation-specific doubt flag. Not flagged does not establish independent validation.","type":"categorical","group":"Provenance"}],"shardSize":250,"acquired":"7 September 2026","preparedAt":"2026-09-07T01:53:32.888061+00:00","recordCount":37027}