- 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, ...
That zone, of variable width, lying between the shoreface and the seaward limit of the breaker zone.
Industry:Earth science
A physical quantity which, to a certain degree of approximation, remains unchanged during a slow spatial or temporal change in a system.
Industry:Earth science
(1) A correction applied to the reading from the scale on any graduated device used for measurement, to compensate for a constant error such as would be caused by displacement of the scale from its proper position.
Industry:Earth science
A vertical control datum with zero at mean sea level at Pointe au Pere, Quebec, as determined from readings over the period 1941-1956. It is used primarily for hydraulic studies and for the definition of chart datums in the Great Lakes and connecting waterways. Elevations on this datum are based on leveling from Point au Pere to Lake Ontario and along all connecting waterways, to Lake Superior. Elevations on the lakes are derived by water-level transfer based on the assumption that the mean water level in each lake, for the months of June, July, August and September during the period 1941-1956, constituted an equipotential surface. Elevations are stated in units of dynamic number as defined by Bowie and Avers, 1914
Industry:Earth science
Not able to be defeated, revoked, or made void. The term is usually applied to an estate or right which cannot be defeated.
Industry:Earth science
The absolute refractive index of an atmosphere; in particular, of the Earth's atmosphere.
Industry:Earth science
A line, on a map, joining points of equal angular difference between grid north and magnetic north.
Industry:Earth science
A single staff or pole on which a surveyor's compass or other instrument was mounted. A Jacob's staff was used instead of a tripod. It was fitted with a ball-and-socket joint at its upper end so that the instrument could be adjusted to a level position. A metallic spur was fitted to the foot so that the staff could be pressed firmly into the ground. Many of the early land surveys in the USA were made with surveyor's compasses mounted on Jacob's staffs.
Industry:Earth science
The average difference between the two high waters or two low waters of the day at the time of tropic tides. The first is called tropic high water inequality; the second is called tropic low water inequality.
Industry:Earth science
A small, rounded hill rising less than 500 fathoms (about 1000 meters) from the floor of the ocean and of limited extent across the summit. The term is sometimes confused with guyot.
Industry:Earth science
