- Industry: 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 mathematical surface which correspond to a hypothetical Earth in the same way that the geoid corresponds to the real Earth.
Industry:Earth science
(1) An instrument for measuring the state of, or recording facts about, a phenomenon. Also spelled gauge. (2) The horizontal distance between the inside heads of the two rails of a railroad track. The distance is measured between points 5/8 inches below the top of the rails. The standard gage in the United States is 4 feet 8½ inches.
Industry:Earth science
A weighted, horizontal disk suspended at its center by a helical spring and at the rim by two threads attached at diametrically opposite points. A change in gravity pulls down and rotates the disk from its position at equilibrium. The amount of rotation is a measure of the change in gravity.
Industry:Earth science
An equipotential surface which would coincide with the average level of the oceans if the waters were at rest. This definitions assumes that the average level of water at rest must be an equipotential surface. It is therefore equivalent to defining the marine geoid as an equipotential surface which would coincide with the average level of the oceans if the oceanic surface were an equipotential surface.
Industry:Earth science
The range of tones, in a picture, from the brightest highlights to the deepest shadows.
Industry:Earth science
The study of the Earth - the materials of which it is made, the processes that act on these materials, the products formed, and the history of the planet and the life on it since its origin. Geology considers the physical forces which act on the Earth (physical geology or geophysics), the chemistry of the materials of which the Earth is made (geochemistry), the shape of the surface (geomorphology) and the biology of past life as evidenced by fossils. It differs from geography, of which it is a part, in not being concerned with present day life on the Earth.
Industry:Earth science
A pentagonal prism having four dihedral angles of 112.5<sup>o</sup> between faces and one dihedral angle of 90<sup>o</sup> between faces.
Industry:Earth science
A variation of the rigid-tripod graver, designed so that the scribing point, the vertical vane, and one supporting leg lie on one line. It is used with a straight-edge for drawing long, straight lines.
Industry:Earth science
