It has long been known that earth has a
magnetic field whichis very similar to the field produced by a huge magnet which
is supposed to beat its centre. Its north pole lies towards the
geographic south and South Poletowards the geographic north. The axis of the earth's
magnetic does not coincidewith the geographic axis, the angle between them being about 19 degree. The positionof the magnetic poles is not well defined on the globe - they are spread overan area. The magnetic pole on the northern hemisphere is located on a peninsulain northern Canada.The opposite magnetic pole in the southern hemisphere lies on the Antarcticcontinent, south of Australia.Earth’s magnetic field is supposed to arise from electric currents in themolten, iron rich outer core surrounding the solid inner core of the earth.Field lines usually or come out of the earth's surface at some angle. The angleis called magnetic inclination or magnetic dip at that place. At magneticpoles, the angle of dip is90degree. The line on the earth's surfacepassing through the places having angle of dip 0 degree is called magneticequator. It passes through Thumb in south India,where the space research centre is located.