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.


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 |