50. 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 bytes)

 

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 D I
Los Angeles 24276 5996 41636 48568 13.9 59.0
New York 19308 -4643 50289 54068 -13.5 68.5
Boston 18006 -1566 53490 56461 -4.9 71.3
Chicago 18686 -803 52908 56117 -2.5 70.5
Miami 25478 -2182 38586 46290 -4.9  
Huston 24892 2050 42441 49245 4.7 59.5
Denver 20895 3878 49938 54272 10.5 66.9
San Francisco 23004 6411 43851 49932 15.5 61.4