Bathymetry
oceantopography
Depth of the sea floor below the sea surface (or geoid), expressed
as positive-down meters. Conceptually elevation underwater — the
ocean analogue to a DTM. Flagship products: GEBCO 2024 (global
15-arc-second grid), EMODnet Bathymetry (European seas, higher
resolution), NOAA ETOPO 2022 (global ice-surface and bedrock).
Used by coastal, marine-habitat, and tsunami-modelling ops.
Canonical units:
m