gravimetry

Click a letter for the index

Or search the encyclopaedia:

 

 

Go

 

Click image to enlarge
Measurement of the Earth's gravitational field. Small variations in the gravitational field (gravimetric anomalies) can be caused by varying densities of rocks and structure beneath the surface. Such variations are measured by a device called a gravimeter (or gravity-meter), which consists of a weighted spring that is pulled further downwards where the gravity is stronger. Gravimetry is used by geologists to map the subsurface features of the Earth's crust, such as underground masses of dense rock such as iron ore, or light rock such as salt.

The large star symbolizes the common programme of the Communist Party. The small stars represent the four economic classes: peasants, workers, petty bourgeoisie, and ‘patriotic capitalists’. Effective date: 1 October 1949. >>