LECTURE DEMONSTRATION MANUAL | Instructional Research Lab : ucla physics
Earth's Magnetic Field

E.3.1 Earth's Magnetic Field

A magnetic declination and inclination needle is provided for determining the direction (deviation and dip angle) of the earth's magnetic field in the classroom.

A globe of the earth may help to illustrate these concepts.

ertmgnfl.gif (4443 

The total magnitude of the magnetic field vector is about 0.5 Gauss units or equivalently 50,000 nanoTeslas (nT). To find the components of the magnetic field anywhere visit the Standard magnetic Field Model and enter the date, and your geographic latitude, longitude and elevation. The table below shows the representative components for June 1, 1999 at sea level. Bx, By and Bz are the components in units of nT, B is the total field strength also in units of nT, D is the declination angle between geographic and magnetic north, and I is the inclination or Dip Angle, in degrees below the local horizontal plane.

Average Magnetic Components
City Bx By Bz B DI
Los Angeles 24276 599641636 48568 13.9 59.0
New York19308 -4643 5028954068 -13.5 68.5
Boston 18006-1566 53490 56461 -4.971.3
Chicago 18686-803 52908 56117-2.5 70.5
Miami 25478 -218238586 46290 -4.9
Huston 248922050 42441 49245 4.759.5
Denver20895 3878 49938 54272 10.566.9
San Francisco23004 6411 43851 4993215.5 61.4

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