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Eng ID Term Definition
5801
Universal Transverse Mercator (UTM) grid
See GRID.
5802
unprotected reversing thermometer
See THERMOMETER.
5803
unrecoverable station
See STATION.
5804
unsurveyed area
An area where HYDROGRAPHIC SURVEY data is non-existent.
5805
unsurveyed clearance depth
The estimated depth over an unsurveyed wreck or obstruction over which the exact depth is unknown but which is considered to have a safe cle... more
The estimated depth over an unsurveyed wreck or obstruction over which the exact depth is unknown but which is considered to have a safe clearance to the depth shown.
5806
upland
The higher GROUND of a region contrasted with the VALLEYS and PLAINS. Used in contrast to LOWLAND.
5807
uplifted reef
A CORAL REEF exposed above water level.
5808
upper branch
That half of a MERIDIAN or CELESTIAL MERIDIAN from POLE to POLE which passes through a place or its ZENITH.
5809
upper culmination
Upper TRANSIT.
5810
upper limb
See LIMB.
5811
upper limit of navigability
The character of a river will, at some point along its length, change from navigable to non‑navigable. Very often that point will be at a ma... more
The character of a river will, at some point along its length, change from navigable to non‑navigable. Very often that point will be at a major fall or rapids, or other place where there is a marked decrease in the navigable capacity of the river. The upper limit will therefore often be the same point traditionally recognized as the head of navigation, but may, under some of the tests described above, be at some point yet farther upstream.
5812
upper transit
See MERIDIAN TRANSIT.
5813
uprush
The rush of water up onto the BEACH following the breaking of a WAVE. See RUN-UP.
5814
upstream
(adj. & adv.). Toward the SOURCE of a STREAM. The opposite is DOWNSTREAM.
5815
upwelling
The process by which water rises from a lower to a higher DEPTH, usually as a result of DIVERGENCE and offshore CURRENTS. See SINKING.
5816
upwind
(adj. & adv.). In the direction from which the WIND is blowing. The opposite is DOWNWIND.
5817
vacuum lead
A CORER which makes use of HYDROSTATIC PRESSURE to force a tube into the BOTTOM SEDIMENT.
5818
valley
A long DEPRESSION or hollow in the LAND lying between HILLS or stretches of high GROUND and usually having a RIVER or STREAM flowing along t... more
A long DEPRESSION or hollow in the LAND lying between HILLS or stretches of high GROUND and usually having a RIVER or STREAM flowing along the bottom.
5819
valley: median
See MEDIAN VALLEY.
5820
valley: submarine
A relatively shallow wide DEPRESSION, the bottom of which usually has a continuous GRADIENT. This term is generally not used for features th... more
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.