Magnetic dip
Encyclopedia
Dip circle
Dip circles are used to measure the angle between the horizon and the Earth's magnetic field . They were used in surveying, mining and prospecting as well as for the demonstration and study of magnetism....
.
Dip angle was discovered by Shen Kuo
Shen Kuo
Shen Kuo or Shen Gua , style name Cunzhong and pseudonym Mengqi Weng , was a polymathic Chinese scientist and statesman of the Song Dynasty...
in the 11th century, who recorded his discovery in his Dream Pool Essays
Dream Pool Essays
The Dream Pool Essays was an extensive book written by the polymath Chinese scientist and statesman Shen Kuo by 1088 AD, during the Song Dynasty of China...
. It was first described in Europe by Georg Hartmann
Georg Hartmann
Georg Hartmann was a German engineer, instrument maker, author, printer, humanist, churchman, and astronomer....
in 1544.
Explanation
Magnetic dip results from the tendency of a magnet to align itself with lines of force. As the Earth's magnetic lines of force are not parallel to the surface, the north end of a compass needle will point downward on the northern hemisphere (positive dip) or upward on the southern hemisphere (negative dip). Contour lines along which the dip measured at the Earth's surface is equal are referred to as isoclinic lines. The locus of the points having zero dip is called the magnetic equator or aclinic line. The range of dip is from -90 degrees to 90 degrees.Importance
The phenomenon is especially important in aviation, as it causes the airplane's compassCompass
A compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the earth. The frame of reference defines the four cardinal directions – north, south, east, and west. Intermediate directions are also defined...
to give erroneous readings during banked turns and airspeed changes.