CATSEA
- gat: a natural or artificial passage or channel
through shoals or steep banks, or across a line of banks lying between two channels. (IHO
Hydrographic Dictionary, S-32, 5th Edition)
- bank: an elevation over which the depth of
water is relatively shallow, but normally sufficient for safe surface navigation. (IHO-IOC
Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- deep: in oceanography, an obsolete term which
was generally restricted to depths greater than 6,000 m. (IHO Hydrographic Dictionary,
S-32, 5th Edition)
- bay: an indentation in the coastline.
- trench: a long narrow, characteristically very
deep and asymmetrical depression of the sea floor, with relatively steep sides. (IHO-IOC
Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- basin: a depression, characteristically in the
deep sea floor, more or less equidimensional in plan and of variable extent. (adapted from
IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- flat: a level tract of land, as the bed of a
dry lake or an area frequently uncovered at low tide. Usually in plural.
- reef: rock lying at or near the sea surface
that may constitute a hazard to surface navigation. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- ledge: a rocky formation continuous with and
fringing the shore. (IHO Hydrographic Dictionary, S-32, 5th Edition)
- canyon: a relatively narrow, deep depression
with steep sides, the bottom of which generally has a continuous slope, developed
characteristically on some continental slopes. (IHO-IOC Publication B-6, Standardization
of Undersea Feature Names, 2nd Edition)
- narrows: a navigable narrow part of a bay,
strait, river, etc. (IHO Hydrographic Dictionary, S-32, 5th Edition)
- shoal: an offshore hazard to surface
navigation that is composed of unconsolidated material. (adapted from IHO-IOC Publication
B-6, Standardization of Undersea Feature Names, 2nd Edition)
- knoll: a relatively small isolated elevation
of a rounded shape. (IHO-IOC Publication B-6, Standardization of Undersea Feature Names,
2nd Edition)
- ridge: (a) A long, narrow elevation with steep
sides. (IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
(b) A long, narrow elevation often separating ocean basins. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition) (c) The linked major mid-oceanic
mountain systems of global extent. Also called mid-oceanic ridge. (adapted from IHO-IOC
Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- seamount: a large isolated elevation, greater
than 1000m in relief above the sea floor, characteristically of conical form. (adapted
from IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- pinnacle: any high tower or spire-shaped
pillar or rock or coral, alone or cresting a summit. It may extend above the surface of
the water. It may or may not be a hazard to surface navigation. (IHO Hydrographic
Dictionary, S-32, 5th Edition)
- abyssal plain: an extensive, flat, gently
sloping or nearly level region at abyssal depths. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- plateau: a flat or nearly flat area of
considerable extent, dropping off abruptly on one or more sides. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- spur: a subordinate elevation, ridge or rise
projecting outward from a larger feature. (IHO-IOC Publication B-6, Standardization of
Undersea Feature Names, 2nd Edition)
- shelf: a zone adjacent to a continent (or
around an island) and extending from the low water line to a depth at which there is
usually a marked increase of slope towards oceanic depths. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- trough: a long depression of the sea floor
characteristically flat bottomed and steep sided and normally shallower than a trench.
(IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- saddle: a broad pass, resembling in shape a
riding saddle, in a ridge or between contiguous seamounts. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- abyssal hills: a tract, on occasion extensive,
of low (100-500m) elevations on the deep sea floor. (adapted from IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- apron: a gently dipping featureless surface,
underlain primarily by sediment, at the base of any steeper slope. (IHO-IOC Publication
B-6, Standardization of Undersea Feature Names, 2nd Edition)
- archipelagic apron: a gentle slope with a
generally smooth surface on the sea floor, characteristically found around groups of
islands or seamounts. (adapted from IHO-IOC Publication B-6, Standardization of Undersea
Feature Names, 2nd Edition)
- borderland: a region adjacent to a continent,
normally occupied by or bordering a shelf, that is highly irregular with depths well in
excess of those typical of a shelf. (IHO-IOC Publication B-6, Standardization of Undersea
Feature Names, 2nd Edition)
- continental margin: the zone, generally
consisting of shelf, slope and rise, separating the continent from the abyssal plain or
deep sea floor. (adapted from IHO-IOC Publication B-6, Standardization of Undersea Feature
Names, 2nd Edition)
- continental rise: a gentle slope rising from
the oceanic depths towards the foot of a continental slope. (IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- escarpment: an elongated and comparatively
steep slope separating or gently sloping areas. Also called: scarp. (IHO-IOC Publication
B-6, Standardization of Undersea Feature Names, 2nd Edition)
- fan: a relatively smooth, fan- like,
depositional feature normally sloping away from the outer termination of a canyon or
canyon system. Also called: cone. (IHO-IOC Publication B-6, Standardization of Undersea
Feature Names, 2nd Edition)
- fracture zone: an extensive linear zone of
irregular topography of the sea floor, characterized by steep-sided or asymmetrical
ridges, troughs or escarpments. (IHO-IOC Publication B-6, Standardization of Undersea
Feature Names, 2nd Edition)
- gap: a narrow break in a ridge or a rise.
(IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- guyot: a seamount having a comparatively
smooth flat top. Also called tablemount. (IHO Hydrographic Dictionary, S-32, 5th Edition
and IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- hill: a small isolated elevation (see also
abyssal hills). (IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd
Edition)
- hole: a local depression, often steep sided,
of the sea floor. (adapted from IHO-IOC Publication B-6, Standardization of Undersea
Feature Names, 2nd Edition)
- levee: a depositional embankment bordering a
canyon, valley or deep-sea channel. (IHO-IOC Publication B-6, Standardization of Undersea
Feature Names, 2nd Edition)
- median valley: the axial depression of the
mid-oceanic ridge system. (IHO-IOC Publication B-6, Standardization of Undersea Feature
Names, 2nd Edition)
- moat: an annular depression that may not be
continuous, located at the base of many seamounts, islands and other isolated elevations.
(IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- mountains: a large and complex grouping of
ridges and seamounts. (IHO-IOC Publication B-6, Standardization of Undersea Feature Names,
2nd Edition)
- peak: a prominent elevation either pointed or
of a very limited extent across the summit. (IHO-IOC Publication B-6, Standardization of
Undersea Feature Names, 2nd Edition)
- province: a region identifiable by a group of
similar physiographic features whose characteristics are markedly in contrast with
surrounding areas. (IHO-IOC Publication B-6, Standardization of Undersea Feature Names,
2nd Edition)
- rise: (a) A broad elevation that rises gently
and generally smoothly from the sea floor. (b) The linked major mid-oceanic mountain
systems of global extent. Also called mid-oceanic ridge. (adapted from IHO-IOC Publication
B-6, Standardization of Undersea Feature Names, 2nd Edition)
- sea channel: a continuously sloping, elongated
narrow depression commonly found in fans or abyssal plains and customarily bordered by
levees on one or both sides. (adapted from IHO-IOC Publication B-6, Standardization of
Undersea Feature Names, 2nd Edition)
- seamount chain: several seamounts in linear or
orcuate alignment. Also called: seamounts. (adapted from IHO-IOC Publication B-6,
Standardization of Undersea Feature Names, 2nd Edition)
- shelf-edge: a narrow zone at the seaward
margin of a shelf along which is a marked increase of slope. Also called: shelf break.
(adapted from IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Ed.)
- sill: a sea floor barrier of relatively
shallow depth restricting water movement between basins. (adapted from IHO-IOC Publication
B-6, Standardization of Undersea Feature Names, 2nd Edition)
- slope: the slope seaward from the shelf edge
to the upper edge of a continental rise or the point where there is a general reduction in
slope. (adapted from IHO-IOC Publication B-6, Standardization of Undersea Feature Names,
2nd Edition)
- terrace: a relatively flat horizontal or
gently inclined surface, sometimes long and narrow, which is bounded by a steeper
ascending slope on one side and by a steeper descending slope on the opposite side.
(IHO-IOC Publication B-6, Standardization of Undersea Feature Names, 2nd Edition)
- valley: a relatively shallow, wide depression,
the bottom of which usually has a continuous gradient. This term is generally not used for
features that have canyon-like characteristics for a significant portion of their extent.
Also called: submarine valley; sea valley. (IHO-IOC Publication B-6, Standardization of
Undersea Feature Names, 2nd Edition)
- canal: an artificial water course used for
navigation.
- lake: a large body of water entirely
surrounded by land. (IHO Dictionary, S-32, 5th Edition, 2629)
- river: a relatively large natural stream of
water.
- reach: a straight section of a river, specially a navigable river between two bends or an arm of the sea extending into the land (adapted from IHO Dictionary, S-32, 5th Edition, 4239)