- 行业: Earth science
- Number of terms: 93452
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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 vertical distance, in the direction of gravity, as determined by echo sounding, from the tidal datum to the sea bottom, using an assumed speed of sound of 800 fathoms (4800 feet) per second and making no corrections for actual speed or actual path of the sound ray.
Industry:Earth science
A coordinate system with its origin the observer's location on the spheroid representing the Earth, and with its other defining axes and planes parallel to those of an equatorial coordinate system having its origin at the center of the spheroid.
Industry:Earth science
A tidal current which flows alternately in approximately opposite directions, with slack water at each reversal. Such currents occur principally in regions where flow is largely restricted to narrow channels.
Industry:Earth science
The set of points, on the Moon's surface, to which coordinates have been assigned either by definition or be determined by measurement, and to which the locations of other points are referred.
Industry:Earth science
(1) A form of ownership less than the whole. (2) The fee ownership of separate portions of multi-storied buildings by statute which provides the mechanism and facilities for formal filing and recordation of a divided interest in real property, where the division is vertical as well as horizontal. (3) A building held in condominium.
Industry:Earth science
The amount by which the observed period P of a pendulum must be increased because the knife edge on which the pendulum swings has a circular rather than V-shaped cross section. The correction amounts to about P/2s, in which s is the quantity √(1 + (d/r)² - 2 (d/r)cos α). r is the radius of curvature of the cross section, d is the distance from the center of gravity to the center of curvature and á is half the angle through which the pendulum swings from side to side. In practice, the radius r may not be measurable; the correction must then be determined empirically.
Industry:Earth science
Dating an event according to both the Julian and the Gregorian calendars. During 1752, Great Britain and her colonies officially replaced the Julian calendar, with 25 March as the beginning of the year, by the Gregorian calendar, with 1 January as the beginning of the year. The difference between the two calendars having increased from 10 days in 1582 to 11 days, the change was made by having 2 September 1752, followed immediately by 14 September 1752. To avoid confusion, dates according to the Julian calendar were marked old style or (O. S. ); dates according to the Gregorian calendar were marked new style or (N. S. ). In double dating early American records, not only the day and the month but also the year are subject to change. In England, at the time of the change, the official year commenced on 25 March, so that 24 March 1730 (O. S. ), corresponded to 4 April 1731 (N. S. ), but the next day was 25 March 1731 (O. S. ), or 5 April 1731 (N. S. ). This practice was not universal, for there was some popular use of 1 January as the beginning of the year even before the official change.
Industry:Earth science
A current moving eastward between the North and South Equatorial Currents of the Atlantic, Pacific, and Indian (in northern winter) Oceans. In the Atlantic and Pacific Oceans, its axis lies about latitude 7<sup>o</sup> North, and in the Indian Ocean, about 7<sup>o</sup> South.
Industry:Earth science
A borrowed word from French for describing a road with dead end, blind alley or court.
Industry:Earth science
