# AGENTS.md - GEBCO Gazetteer of Undersea Feature Names

Guidance for AI agents and LLMs working with this collection.

## Overview

Names, generic feature types and geometries of seafloor features (seamounts, canyons, banks, ridges, basins, guyots, fracture zones, trenches ...) approved by the IHO-IOC GEBCO Sub-Committee on Undersea Feature Names (SCUFN), from the NOAA NCEI / IHO DCDB Undersea_Features feature service. The service has three layers, one per geometry type (2,632 points, 1,128 lines, 1,652 polygons), all kept here with the per-row `geom_type` (MultiPoint, MultiLineString or MultiPolygon) and `component` (point, line, polygon). `FEATURE_ID`, the gazetteer's permanent feature number, is the id: a feature that the service serves as both a point and an extent (101 do) keeps `GEBCO:<FEATURE_ID>` on its polygon (else line) and gets `:point` or `:line` on the other rows.

Licence LicenseRef-IHO-IOC-GEBCO-Gazetteer; credit: IHO-IOC GEBCO Gazetteer of Undersea Feature Names, www.gebco.net. Served by the IHO Data Centre for Digital Bathymetry (IHO DCDB) and NOAA National Centers for Environmental Information (NCEI). Processed by Ocean Metrics.

## Find a place

```sql
SELECT * FROM read_parquet('https://storage.oceanmetrics.io/gazetteer/gebco_undersea/places.parquet')
WHERE name ILIKE '%california%';
```

`place_id` is unique and prefixed; `status` / `status_source` / `status_date` say whether the place is current and
where that is documented. Check `status` before treating a lease or area as live.

## Render on a map

Load `places.pmtiles` (layer `gebco_undersea`) into MapLibre GL via the PMTiles protocol; `styles/default.json` is a starting style.