geoenrich 0.7.0

Enrich longitude/latitude points with coast distance, bathymetric depth, sea name, and nearest country/municipality
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# depth

Bathymetric depth at each point, from a GEBCO gridded NetCDF file.

```bash
geoenrich depth <INPUT> --data <GEBCO.nc> [OPTIONS]
```

Appends one column, `bathymetry` (rename with `--column`), holding the GEBCO
elevation at each point in meters.

## How it works

GEBCO is a regular lon/lat grid, so no nearest-neighbor search is needed. The
`lat` and `lon` axes are read once to learn each axis origin and spacing, then
every point maps straight to its nearest grid cell by arithmetic and reads the
single `elevation` cell. Longitudes are normalized to `[-180, 180)`, and points
off the grid yield a null.

GEBCO elevation is negative below sea level. By default the value is reported as
stored (negative under water); `--positive` flips the sign so depth reads
positive under water and land reads negative.

This command needs no [region](../reference/regions.md): a grid lookup is
global by construction.

## Options

Beyond the [shared options](../reference/configuration.md):

| Option | Default | Meaning |
|--------|---------|---------|
| `--data <FILE>` | required | GEBCO bathymetry NetCDF file |
| `--positive` | off | Report depth as positive below sea level |
| `--column <NAME>` | `bathymetry` | Output column name |

## Example

```bash
# Reading and writing gzipped CSV
geoenrich depth cores.csv.gz \
  --data ./data/gebco/GEBCO_2024_sub_ice.nc \
  --positive -o cores.depth.csv.gz
```

The `depth` command links the HDF5 / NetCDF C libraries; see
[Installation](../installation.md). See [Reference datasets](../data.md) for how
to obtain the GEBCO grid.