*origin of the earth's magnetic field

• we've gone from thinking the earth was made from magnetic rocks to knowing the high temperatures deep inside the earth cause rocks to lose any magnetism they had and knowing the earth's magnetic field has reversed in the past (last change was around 500 000yrs ago when north was rlly north)
• The earth's core is the origin of the magnetic field
• Scientists guess on the earths core being the origin of the magnetic field

  the heat generated in teh core made from iron causing it to continually create a magnetic field
• the core also contains nickel (magnetic metal) and the movement in the liquid outer core would explain why the magnetic poles move slowly and occasionally reversed
• magnetic north moves at a speed of about 60km per yr