- Branche: Earth science
- Number of terms: 93452
- Number of blossaries: 0
- Company Profile:
Founded in 1941, the American Congress on Surveying and Mapping (ACSM) is an international association representing the interests of professionals in surveying, mapping and communicating spatial data relating to the Earth's surface. Today, ACSM's members include more than 7,000 surveyors, ...
The quantity used, in reduction of distances measured with radio waves, to account for the effect of atmospheric refraction on the measured length.
Industry:Earth science
The film speed of a photographic material, determined on the basis of the exposure corresponding to a particular gradient of the characteristic curve.
Industry:Earth science
Measurement of the force or acceleration of gravity by any method not requiring a knowledge of the value of gravity elsewhere.
Industry:Earth science
A gravimeter having a mechanical or optical connection between the test mass and the scale such that a change of position of the mass can be read directly.
Industry:Earth science
A gravimeter which measures gravity by the amount of extension in a spring holding a weight in balance.
Industry:Earth science
Having a length greater than or shorter than the length of any other line in the same space between the same two points. Unless specified otherwise, the shortest length is usually meant. The word has more precise definitions framed to include lines in more general spaces than the ordinary Euclidian ones, but those are of interest primarily to mathematicians.
Industry:Earth science
A proof made by printing from type on a printer's galley before it is set up in pages.
Industry:Earth science
A large mass of ice formed, at least in part, on land by compaction and recrystallization of snow, and creeping slowly downward or outward in all directions under the force of its own weight, and surviving from year to year. The term covers ice sheets and ice shelves which are fed in part by ice formed on land, as well as the small glaciers formed in mountainous valleys. It is sometimes restricted to denote only glaciers occurring in mountainous valleys. Such glaciers are otherwise distinguished as Alpine glaciers, valley glaciers or ice streams. The first systematic mapping of glaciers was done by L. Agassiz about 1840, using a plane table. S. Finsterwalder used tachymetry and triangulation about 1886 for mapping glaciers, and introduced photogrammetric surveying in 1889 for the same purpose.
Industry:Earth science
A weighted, horizontal disk suspended by a spiral spring attached at its center and by three threads attached at equal intervals around its rim. The disk is in torsional equilibrium; the weight of the disk tends to pull the disk down and around so as to lower the tension of the threads, but the torsion of the spring keeps the disk in place. Changing gravity turns the disk, which is brought back to its original position by turning the spring through a measured angle.
Industry:Earth science
