Undersea mountains

This document describes the classification and recommended symbolization for three datasets, which are the result of automated analysis of a compiled depth dataset for the detection and delineation of undersea mountains.

SymbolNameDefinition/descriptionCode
PEAKS - RELATIVE HEIGHT (HKl)
200 – 500 m Peak points indicate the main peak(s) of the mapped undersea mountains. The peak's height above the surrounding seabed (relative height) is 200 - 500 m. u500
500 – 1000 m Peak points indicate the main peak(s) of the mapped undersea mountains. The peak's height above the surrounding seabed (relative height) is 500 - 1000 m. u1000
> 1000 m Peak points indicate the main peak(s) of the mapped undersea mountains. The peak's height above the surrounding seabed (relative height) is over 1000 m. o1000
PEAKS - DATA QUALITY (DataKvKl)
Direct measurements Indicates the quality of the bathymetry data in the vicinity of each peak. The class is based on the majority data type according to GEBCO TID grid and percentage within 20 km radius around each point location. Direct: >90% majority direct dd
Partially indirect measurements Indicates the quality of the bathymetry data in the vicinity of each peak. The class is based on the majority data type according to GEBCO TID grid and percentage within 20 km radius around each point location. Partial: 50%-90% majority direct di
Indirect measurements Indicates the quality of the bathymetry data in the vicinity of each peak. The class is based on the majority data type according to GEBCO TID grid and percentage within 20 km radius around each point location. Indirect: majority (<50%) indirect ii
PEAKS - DEPTH (ToppDybde)
< 500 m The depth of the peak below sea level is less than 500 m. 500
500 - 1200 m The depth of the peak below sea level is 500 - 1200 m. 500 - 1200
1200 - 2000 m The depth of the peak below sea level is 1200 - 2000 m. 1200 - 2000
> 2000 m The depth of the peak below sea level is over 2000 m. > 2000
PEAKS - NEIGHBOURING TERRAIN (ToppNaboKl)
Peak in flat terrain Distinct peak with surrounding flat terrain F
Peak in rugged terrain Peak located in rugged terrain. R

SymbolNameDefinition/descriptionCode
MOUNTAINS AND RIDGES (ELEVATED TERRAIN POLYGONS) - MORPHOLOGY AND HEIGHT CLASS (MorfH)
Mounds and ridges (200 - 500 m) Mounds and ridges with height above the surrounding seabed (relative height) between 200 and 500 m. MR_u500
Knolls and ridges (500 - 1000 m) Knolls and ridges with height above the surrounding seabed (relative height) between 500 and 1000 m. KR_u1000
Seamounts and ridges (> 1000 m) Seamounts and ridges with height above the surrounding seabed (relative height) over 1000 m. SR_o1000

SymbolNameDefinition/descriptionCode
UNDERSEA MOUNTAINS - DATA COVERAGE
Data coverage Polygon delimiting the area where analyses of bathymetry data have been conducted for mapping undersea mountains.
Last updated 08.10.2025

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