{ "edition": "2026-09-20", "scope": "Initial assessment and research opportunities; not a completed worldwide inventory or a dated reconstruction of all ancient coasts.", "sources": [ { "id": "subnordica", "title": "SUBNORDICA: beyond submerged landscapes", "url": "https://projects.au.dk/subnordica/about", "kind": "active project", "checked": "2026-09-19", "note": "Official project period: April 2024–March 2030. Uses North Sea and Baltic data to develop methods for identifying archaeological targets." }, { "id": "northsea-peats", "title": "Global sea-level rise in the early Holocene revealed from North Sea peats", "url": "https://www.nature.com/articles/s41586-025-08769-7", "kind": "research paper", "checked": "2026-09-19", "note": "Hijma et al., 2025. Dated peat sequences, regional land-motion corrections and uncertainty; a route toward a defensible regional reconstruction." }, { "id": "northsea-data", "title": "North Sea peats: supplementary information and data", "url": "https://zenodo.org/records/10801302", "kind": "open data", "checked": "2026-09-19", "note": "Repository API checked: CC BY 4.0. Contains the HOLSEA spreadsheet, age-calibration scripts, core photographs, technical documentation and model grids. Files listed; scientific contents not yet independently reanalysed." }, { "id": "cambay", "title": "Major marine archaeological discovery in the Gulf of Cambay and its significance", "url": "https://www.asiaoceania.org/amos/pdf/2004/57-OBG-M239.pdf", "kind": "proposing researchers’ abstract", "checked": "2026-09-19", "note": "Kathiroli and NIOT colleagues, 2004 conference abstract. Reports sonar patterns, palaeochannel-like features and grab/dredge samples. The source proposes structures; it is not an independent confirmation of that interpretation." }, { "id": "pavlopetri", "title": "Pavlopetri Underwater Archaeology Project: research impact record", "url": "https://impact.ref.ac.uk/casestudies/CaseStudy.aspx?Id=28862", "kind": "institutional research record", "checked": "2026-09-19", "note": "Documents the project begun in 2009, mapped buildings and ceramics indicating occupation from about 3500 BCE through the Bronze Age. Historical project record; current fieldwork not verified." }, { "id": "pavlopetri-survey", "title": "Pavlopetri: 2010 field report", "url": "https://chronique.efa.gr/?id=1893&r=report", "kind": "field report", "checked": "2026-09-19", "note": "Reports structural survey, sector-scan sonar and stereo photogrammetry. A useful example of multiple recording methods applied to the same identified site." }, { "id": "murujuga", "title": "Aboriginal artefacts on the continental shelf reveal ancient drowned cultural landscapes in northwest Australia", "url": "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233912", "kind": "research paper", "checked": "2026-09-19", "note": "Benjamin et al., 2020. Reports Cape Bruguieres and Flying Foam Passage, combining remote sensing and diver inspection. Site-formation and sea-level reasoning must accompany the artefact claims." }, { "id": "baltic-wall", "title": "A submerged Stone Age hunting architecture from the Western Baltic Sea", "url": "https://pubmed.ncbi.nlm.nih.gov/38346187/", "kind": "research paper / indexed abstract", "checked": "2026-09-19", "note": "Geersen et al., 2024; DOI 10.1073/pnas.2312008121. Hydroacoustic, sediment and optical observations support an anthropogenic wall interpretation. Hunting use and age are contextual inferences." }, { "id": "sunda", "title": "Prehistoric human migration between Sundaland and South Asia was driven by sea-level rise", "url": "https://www.nature.com/articles/s42003-023-04510-0", "kind": "research paper", "checked": "2026-09-19", "note": "2023 study combining sea-level and population models. The reconstructed landscape is relevant to targeting; it is not a discovery of a submerged city." }, { "id": "lambeck", "title": "Sea level and global ice volumes from the Last Glacial Maximum to the Holocene", "url": "https://doi.org/10.1073/PNAS.1411762111", "kind": "research paper", "checked": "2026-09-19", "note": "Lambeck et al., 2014. Global ice-volume and sea-level history distinguishes the glacial maximum from later deglaciation and regional relative sea level." }, { "id": "gebco", "title": "GEBCO_2025 Grid and Type Identifier grid", "url": "https://www.gebco.net/data-products-gridded-bathymetry-data/gebco2025-grid", "kind": "dataset documentation", "checked": "2026-09-19", "note": "Versioned global 15 arc-second elevation compilation. The TID grid identifies input-data types; spatial grid spacing must not be treated as uniform survey accuracy." }, { "id": "emodnet", "title": "EMODnet Bathymetry DTM 2024 release", "url": "https://emodnet.ec.europa.eu/en/emodnet-bathymetry-dtm-2024-release", "kind": "dataset documentation", "checked": "2026-09-20", "note": "DTM 2024: 1/16 arc-minute spacing, approximately 115 m north–south. Depths referenced to Lowest Astronomical Tide, not mean sea level. Source and interpolation flags matter." }, { "id": "emodnet-api", "title": "EMODnet DTM 2024: ERDDAP data access", "url": "https://erddap.emodnet.eu/erddap/griddap/bathymetry_dtm_2024.html", "kind": "data service", "checked": "2026-09-19", "note": "Metadata endpoint checked. Variables include elevation, source index, count and interpolation flag; these help audit provenance rather than treating every pixel as measured." }, { "id": "etopo", "title": "NOAA ETOPO1: versioned ERDDAP relief dataset", "url": "https://coastwatch.pfeg.noaa.gov/erddap/info/etopo180/index.html", "kind": "data service", "checked": "2026-09-19", "note": "The demonstrator uses small subsamples of this older 2009 global relief model. Four actual NetCDF downloads and hashes are retained. Mean-sea-level elevations; not an ancient coastline model." }, { "id": "ncei", "title": "NCEI Marine Trackline Geophysical Data", "url": "https://www.ncei.noaa.gov/products/marine-trackline-geophysical-data", "kind": "data archive", "checked": "2026-09-19", "note": "Searchable bathymetry, sub-bottom, side-scan, magnetic, gravity and seismic records. Coverage and acquisition quality vary by survey; some files require additional handling." }, { "id": "satellites", "title": "ESA: satellite-derived bathymetry", "url": "https://knowledge-hub-gda.esa.int/eo_capability/bathymetry/", "kind": "method documentation", "checked": "2026-09-19", "note": "Optical shallow-water method sensitive to clarity, clouds, glint and bottom properties. Different from inferring broad seafloor relief through satellite altimetry." }, { "id": "satellite-study", "title": "Space-borne bathymetry with ICESat-2 and Sentinel-2", "url": "https://ntrs.nasa.gov/citations/20210011367", "kind": "research record", "checked": "2026-09-19", "note": "NASA-hosted 2021 study describes calibration and validation of shallow, clear-water bathymetry. No universal depth limit or archaeological-detection capability is implied." }, { "id": "copernicus", "title": "Copernicus Data Space Ecosystem", "url": "https://dataspace.copernicus.eu/", "kind": "data access portal", "checked": "2026-09-19", "note": "Portal for Sentinel observations. This edition links acquisition access; no satellite scene has yet been processed for this programme." }, { "id": "baltic-auv", "title": "Baltic AUV survey · 0.5 m grid", "url": "https://doi.iow.de/10.12754/DATA-2024-0001", "kind": "downloaded primary dataset", "checked": "2026-09-20", "note": "Geersen 2024, DLR AUV survey in 2023, CC BY 4.0. Original ZIP retained with SHA-256; local resolution audit completed. Vertical datum unresolved in GeoTIFF metadata." }, { "id": "subnordica-ai", "title": "SUBNORDICA: AI for Stone Age archaeology", "url": "https://projects.au.dk/subnordica/research/work-package-3", "kind": "project methods", "checked": "2026-09-20", "note": "Official work package includes testing AI/ML methods for archaeological targets. It does not supply validation for this project’s analyses." } ], "projects": [ { "id": "doggerland", "name": "Doggerland & the North Sea", "label": "A landscape we can begin to reconstruct", "status": "Active programme + published landscape evidence", "activity": "SUBNORDICA · April 2024–March 2030", "lat": 54.5, "lon": 3.0, "region": "northsea", "precision": "regional anchor", "finding": "Peat records, buried channels and surveys constrain former landscapes. SUBNORDICA is developing methods to identify archaeological targets.", "limit": "A mapped river or dated peat bed does not by itself identify a settlement. Modern seabed relief may overlie a buried land surface.", "next": "Start with the open sea-level database and source-quality layers; reproduce a regional reconstruction before ranking candidate habitats.", "sources": [ "subnordica", "northsea-peats", "northsea-data", "subnordica-ai" ] }, { "id": "cambay", "name": "Gulf of Khambhat / Cambay", "label": "A claim that needs its original context", "status": "Disputed structure interpretation", "activity": "NIOT reports from the early 2000s; a current excavation programme was not verified", "lat": 21.2, "lon": 72.5, "region": "khambhat", "precision": "regional anchor, not an exact feature position", "finding": "NIOT researchers report sonar geometries and dredged samples. A dated, in-situ settlement has not been independently verified here.", "limit": "The source’s grab/dredge samples do not, on their own, establish that dated material belongs to a human-built feature. This edition has not independently verified the reported city interpretation.", "next": "Seek original georeferenced sonar lines, processing history, repeat surveys and sample-context records. Separate a natural-feature test from a chronology test.", "sources": [ "cambay" ] }, { "id": "pavlopetri", "name": "Pavlopetri, Greece", "label": "A submerged settlement, recorded in detail", "status": "Documented archaeological site", "activity": "Published survey and excavation programme begun in 2009; ongoing work not asserted", "lat": 36.518, "lon": 22.989, "region": "world", "precision": "approximate site", "finding": "Buildings, streets and ceramics document a settlement spanning the Final Neolithic and Bronze Age.", "limit": "This is a much later settlement than 12,000 years ago. Its submergence history cannot be applied to every shelf or monument.", "next": "Use the survey as a positive control for recording methods: which architectural features survive in bathymetry, sonar and diver photography?", "sources": [ "pavlopetri", "pavlopetri-survey" ] }, { "id": "murujuga", "name": "Murujuga’s submerged country", "label": "Stone artefacts in a drowned coastal landscape", "status": "Published archaeological discoveries", "activity": "Deep History of Sea Country research reported in 2020; current field status not checked", "lat": -20.5, "lon": 116.7, "region": "world", "precision": "regional anchor", "finding": "Underwater stone artefacts at Cape Bruguieres and Flying Foam Passage show the potential of surveyed drowned landscapes.", "limit": "Transport, erosion and site formation matter. The inferred exposure history is not direct dating of every stone artefact.", "next": "Follow the published landscape-prediction method and engage the relevant Traditional Owners before any field-oriented extension.", "sources": [ "murujuga" ] }, { "id": "baltic", "name": "The Baltic stone alignment", "label": "A testable interpretation beneath 21 metres of water", "status": "Published structure; function inferred", "activity": "Geersen and colleagues · 2024 study", "lat": 54.1, "lon": 11.5, "region": "world", "precision": "regional anchor", "finding": "Hydroacoustic, optical and sediment surveys document a roughly kilometre-long stone alignment. The authors interpret it as hunting architecture.", "limit": "The existence and layout of stones are observations. Hunting function and the timing of construction depend on contextual arguments.", "next": "The local resolution audit now measures detail loss. Next: independent feature labels and natural look-alikes for a detection benchmark.", "sources": [ "baltic-wall", "baltic-auv" ] }, { "id": "sundaland", "name": "The Sunda shelf", "label": "A very large landscape with a much thinner archaeological record", "status": "Reconstructed landscape / targeting opportunity", "activity": "Published sea-level and population modelling, including a 2023 study", "lat": 1.0, "lon": 108.0, "region": "sunda", "precision": "regional anchor", "finding": "Lower sea levels exposed extensive terrain between today’s islands. Published models examine inundation and population history.", "limit": "Exposed terrain is not evidence of a lost city or of one connected civilisation. Local preservation, sediment burial and survey coverage remain decisive.", "next": "Identify accessible seismic and sediment datasets, then test palaeochannels and freshwater margins against a dated regional model.", "sources": [ "sunda", "lambeck" ] } ], "datasets": [ { "id": "baltic-auv", "name": "Baltic AUV survey", "coverage": "Blinkerwall, Baltic Sea", "resolution": "0.5 × 0.5 m grid; 663,281 valid cells", "access": "CC BY 4.0; GeoTIFF downloaded and retained. Reproducible resolution audit completed.", "use": "A real survey for testing detail loss before developing an archaeological detector.", "limit": "One known site, without independent training/test labels. Datum metadata unresolved; within-survey relief only.", "sources": [ "baltic-auv", "baltic-wall" ] }, { "id": "northsea-history", "name": "North Sea sea-level records", "coverage": "North Sea / Doggerland", "resolution": "Dated point observations, uncertainty, core logs and model grids", "access": "CC BY 4.0 repository; file list and licence checked", "use": "Reproduce regional relative sea-level constraints, distinguish limiting points from index points, and propagate age/elevation uncertainty.", "limit": "The scientific spreadsheets and grids have not yet been independently reanalysed here. Some grids are large; start with the database and documentation.", "sources": [ "northsea-data", "northsea-peats" ] }, { "id": "gebco-relief", "name": "GEBCO_2025 + source types", "coverage": "Global", "resolution": "15 arc-second grid spacing; effective survey resolution varies", "access": "Open downloads and regional subsets under GEBCO terms", "use": "Screen shelf morphology and inspect the Type Identifier layer before deciding where higher-quality data are needed.", "limit": "A fine-looking grid can incorporate inferred or interpolated depths. It cannot resolve or authenticate small archaeological structures by itself.", "sources": [ "gebco" ] }, { "id": "emodnet-relief", "name": "EMODnet DTM 2024", "coverage": "European seas, plus a separate Caribbean product", "resolution": "1/16 arc-minute spacing; about 115 m north–south", "access": "Open portal and ERDDAP; service metadata checked", "use": "Combine elevations with source indices and interpolation flags. Search for finer contributing surveys around a chosen study area.", "limit": "Depths use Lowest Astronomical Tide. Align vertical datums before comparison with mean-sea-level grids; inspect source and interpolation flags.", "sources": [ "emodnet", "emodnet-api" ] }, { "id": "survey-lines", "name": "NCEI survey and trackline archive", "coverage": "Worldwide, uneven survey coverage", "resolution": "Survey-specific: single/multibeam, sonar and seismic products", "access": "Searchable archive with downloadable formats; inspect each cruise’s metadata", "use": "Locate actual survey lines and sub-bottom records, distinguish measured coverage from a seamless-looking global basemap.", "limit": "A catalogue hit is not yet an analysis-ready dataset. Navigation, instruments, processing and time/depth conversion can matter.", "sources": [ "ncei" ] }, { "id": "optical", "name": "Sentinel-2 + ICESat-2 opportunities", "coverage": "Suitable shallow, clear-water coasts", "resolution": "Sensor- and method-specific; optical pixels are not depth accuracy", "access": "Sentinel portal linked; method papers checked; no local scenes processed yet", "use": "Pilot shallow-water depth estimation where water clarity and validation soundings make it appropriate.", "limit": "Cloud, turbidity, glint, depth and bottom reflectance limit optical recovery. This is not a method to see through arbitrary deep or muddy water.", "sources": [ "copernicus", "satellites", "satellite-study" ] }, { "id": "prototype", "name": "This explorer’s retained relief grids", "coverage": "World, North Sea, Sunda and Gujarat subsets", "resolution": "Subsampled ETOPO1: 20′ global; 3′ North Sea; 6′ Sunda; 2′ Gujarat", "access": "Actual downloaded NetCDF source files retained; compact grids and hashes published", "use": "Understand shelf geometry and explore how changing a depth threshold alters the area highlighted.", "limit": "Older 2009 relief compilation; deliberately coarse. It is an orientation tool, not a dated shoreline or an archaeological detector.", "sources": [ "etopo" ] } ] }