| --- |
| license: cc0-1.0 |
| tags: |
| - geospatial |
| - pmtiles |
| - bathymetry |
| - maps |
| - ocean |
| - hydrography |
| - isambard-ai |
| --- |
| |
| > ⚠️ **NOT FOR NAVIGATION.** |
| > This dataset is not intended for navigation, route planning, marine operations, |
| > legal compliance, or any safety-critical purpose. It is intended for |
| > visualisation, exploration, education, and research only. All data and software |
| > are provided "as is" without warranty of any kind. |
|
|
| A global bathymetric dataset optimised for web-native mapping, built as part of |
| a visualisation project about Caribbean Mermaids. The data is processed from |
| GEBCO source grids into PMTiles archives that stream efficiently to the browser |
| via HTTP Range Requests — no tile server required. |
|
|
| ## Companion Repository |
|
|
| This dataset is part of the |
| [global-bathymetry-pmtiles](https://github.com/markmclaren/global-bathymetry-pmtiles) |
| project, which includes the processing scripts and a high-performance web-based |
| globe viewer with 2D/3D modes, real-time palette switching, and vertical |
| exaggeration controls. |
|
|
| ## Available Files |
|
|
| - `gebco_2026_terrain_rgb.pmtiles`: GEBCO 2026 global bathymetry in **Terrain-RGB** format (6.0 GB). |
| - `gebco-2025-rawrgb-z0-6-webp.pmtiles`: GEBCO 2025 low-resolution overview in **Raw RGB** (WebP format, 204 MB). |
| - `land.pmtiles`: Land polygons derived from **Natural Earth** data (16.9 MB). |
|
|
| ## Compute & Provenance |
|
|
| The processing of the GEBCO grids into PMTiles for this project was performed using the **Isambard-AI** supercomputing service. |
|
|
| > "This work used the Isambard-AI service (https://isambard.ac.uk) provided by the University of Bristol and funded by UK Research and Innovation (UKRI)." |
|
|
| **Technical Citation:** |
| McIntosh-Smith, S., et al. (2024). Isambard-AI: a leadership class supercomputer optimised specifically for Artificial Intelligence. [arXiv:2410.11199](https://arxiv.org/abs/2410.11199). |
|
|
|
|
|
|
| ## Format & Technical Details |
|
|
| - **Format:** PMTiles, optimised for HTTP Range Request streaming in web |
| mapping clients. |
| - **Encoding:** RGB channels encode raw elevation and depth values in metres. |
| No colour palette is applied — styling must be handled client-side. |
| - **Storage:** Large files are managed via the Hugging Face CLI (`hf`) using |
| Xet storage, avoiding local Git LFS overhead. |
|
|
| ## Data Attribution |
|
|
| Two GEBCO grid releases are used in this dataset: |
|
|
| - GEBCO Compilation Group (2025) GEBCO 2025 Grid |
| (doi:10.5285/37c52e96-24ea-67ce-e063-7086abc05f29) — zoom levels 0–6 |
| - GEBCO Bathymetric Compilation Group (2026) GEBCO 2026 Grid |
| (doi:10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa) — zoom levels 0–10 |
|
|
| The GEBCO Grid is placed in the public domain and may be used free of charge. |
| This dataset does not claim any official status and is not endorsed by GEBCO, |
| the IHO, or the IOC. For more information visit [gebco.net](https://www.gebco.net/). |
|
|
| ### Natural Earth Data |
|
|
| Land polygons are derived from [Natural Earth](https://www.naturalearthdata.com/). |
| "Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com." |
| Natural Earth data is public domain. |
