Use the “Quick Search” box to locate your required term and/or definition. The following “Search conditions” can be used to refine your search: “Contains”, “Begins with”, “Ends with”, “Equals”, “Does not contain” or “Does not equal.”
Eng ID Term Definition
1781
false target
See ECHO: FALSE.
1782
fan
A relatively smooth, fan-like depositional feature normally sloping away from the outer termina­tion of a CANYON or canyon system. Also call... more
A relatively smooth, fan-like depositional feature normally sloping away from the outer termina­tion of a CANYON or canyon system. Also called CONE.
1783
farad
The unit of electrical capacitance, in the SI SY­STEM.
1784
farewell buoy
The outermost BUOY marking the ENTRANCE to a CHANNEL or HARBOUR. Also called sea buoy. Known as landfall buoy in British terminology.
1785
fast ice
SEA ICE which remains fast, generally in the position where originally formed, and which may attain a considerable thickness. It is found al... more
SEA ICE which remains fast, generally in the position where originally formed, and which may attain a considerable thickness. It is found along COASTS, where it is attached to the SHORE, or over SHOALS, where it may be held in position by ISLANDS, grounded ICEBERGS or grounded polar ice.
1786
fata morgana
The name originally given to a multiple mirage phenome­non often observed over the Straits of Messina, and supposed to be the work of the fa... more
The name originally given to a multiple mirage phenome­non often observed over the Straits of Messina, and supposed to be the work of the faity (in Italian: fata) Morgana; later, it was applied to any impressive multiple MIRAGE.
1787
fathogram
A graphic record of depth measurements obtained by a fathometer (erroneously applied to any ECHOGRAM).
1788
fathom
A unit of length equal to 6 FEET or 1.83 ME­TRES.
1789
fathom curve
See FATHOM LINE, DEPTH CURVE.
1790
fathom line
A DEPTH CURVE with DEPTH expressed in FATHOMS. Also called fathom curve, isobath.
1791
fault
In GEOLOGY, a break of shear in the EARTH's CRUST with an observable displace­ment between the two sides of the break, and parallel to the p... more
In GEOLOGY, a break of shear in the EARTH's CRUST with an observable displace­ment between the two sides of the break, and parallel to the plane of the break.
1792
Faye anomaly
See FREE-AIR ANOMALY.
1793
feature code
An alphanumeric code (label) attached to all point, line or area data describing a cartogra­phic feature of particular quality.
1794
Federation of Astronomical and Geophysical Services (FAGS)
Facilitates and promotes the collection of observations, information and statistics in the field of astronomical and geophysical sciences. T... more
Facilitates and promotes the collection of observations, information and statistics in the field of astronomical and geophysical sciences. The Interna­tional Time Bureau is one of the services.
1795
fender
A device let down between the side of a ship or a WHARF or other ship to protect from chafing when ships are lying alongside or to take the ... more
A device let down between the side of a ship or a WHARF or other ship to protect from chafing when ships are lying alongside or to take the shock of a bump when going al­ongside.
1796
fetch
An area of the sea surface over which SEAS are generated by a WIND having a constant direction and SPEED. The length of the generating area,... more
An area of the sea surface over which SEAS are generated by a WIND having a constant direction and SPEED. The length of the generating area, measured in the direction of the WIND in which the SEAS are generated.
1797
fiducial axes
In PHOTOGRAM­METRY, the lines joining opposite FIDUCIAL MARKS on a PHOTOGRAPH. Also called photograph axes.
1798
fiducial marks
In PHOTO­GRAMMETRY, INDEX MARKS, usual­ly four, which are rigidly connected with the camera lens through the camera body and which form IMAG... more
In PHOTO­GRAMMETRY, INDEX MARKS, usual­ly four, which are rigidly connected with the camera lens through the camera body and which form IMAGES on the NEGATIVE and usually define the PRINCIPAL POINT of the PHOTOGRAPH. Also marks, usually four in number, in any instru­ment, which define the axes whose intersection fixes the PRINCIPAL POINT of a PHOTO­GRAPH and fulfills the requirements of INTERIOR ORIENTATION. In SURVEYING, an index line or point. A line or point used as a basis of reference.
1799
field board
(British terminology). Wooden board, or zinc or plastic sheet, used by HYDROGRAPHERS and land surveyors for plotting and recording the detai... more
(British terminology). Wooden board, or zinc or plastic sheet, used by HYDROGRAPHERS and land surveyors for plotting and recording the details of the SURVEY in the field. Separate boards are usually prepared for TOPOGRAPHY and SOUNDING respectively. The former are referred to as topography boards; the latter as sounding boards. See also BOAT SHEET, and PLANE TABLE.
1800
field chart
See CHART.